Largest exhaust valve possible on LT1 and Vortec heads
Thread Starter
Registered User
Joined: Jul 1999
Posts: 211
From: craplanta ga
so since you spojke from your experence i take it that you have used a large valve on a vortec or lt1 head????????As you put it..
Trust me behind a PC is not the place id be insuliting you if i ever felt the need..Actually i do know the rules..The topic has been discussed at the season opener with PRO officials and if you look back the camshaft wont be in the engine at the atlanta meet..
Trust me behind a PC is not the place id be insuliting you if i ever felt the need..Actually i do know the rules..The topic has been discussed at the season opener with PRO officials and if you look back the camshaft wont be in the engine at the atlanta meet..
Banned
Joined: Oct 2002
Posts: 6,518
Other than you don't come off really well to anyone here, some comments on the Pro Cheap Street Engine for the other guys around here.
I'd love to see these engine rules in the Engine Masters Contest one year, that would be a very fun contest to do that year.
385 max cubes, no 400 blocks. I'd rather do a 377 w/ a 400 block but that's illegal. A 383 means you also have to run 180lbs more weight.
Cylinder heads leave you with very little choices. E-Tec or Vortec's are the good choices. The valve job here is very important, the valve size isin't really going to matter since you can't go any bigger than a 1.60" exhaust valve. Intake manifold choices are important here too.
Unless you are looking at a Ford engine setup here, you have to be creative to get a good setup, but a offset ground 351 crank would get you where you want to go, or maybe not. Being creative with pistons and rods will get you a cheap setup there. I'd also look at the aftermarket heads you get to run there too, only thing bad I see with the Ford is the large journal size on the crank.
Stop looking at the dam valve size, you can't change the port anyways to match it so why bother? I would spend my time and money on the things that can't be claimed. Going with a good setup like a Wilson Plate N2O System would be very beneficial as would using the right header.
BTW I like the launcher setup, if it's "legal" or not that's yet to be determined.
Bret
I'd love to see these engine rules in the Engine Masters Contest one year, that would be a very fun contest to do that year.
385 max cubes, no 400 blocks. I'd rather do a 377 w/ a 400 block but that's illegal. A 383 means you also have to run 180lbs more weight.
Cylinder heads leave you with very little choices. E-Tec or Vortec's are the good choices. The valve job here is very important, the valve size isin't really going to matter since you can't go any bigger than a 1.60" exhaust valve. Intake manifold choices are important here too.
Unless you are looking at a Ford engine setup here, you have to be creative to get a good setup, but a offset ground 351 crank would get you where you want to go, or maybe not. Being creative with pistons and rods will get you a cheap setup there. I'd also look at the aftermarket heads you get to run there too, only thing bad I see with the Ford is the large journal size on the crank.
Stop looking at the dam valve size, you can't change the port anyways to match it so why bother? I would spend my time and money on the things that can't be claimed. Going with a good setup like a Wilson Plate N2O System would be very beneficial as would using the right header.
BTW I like the launcher setup, if it's "legal" or not that's yet to be determined.
Bret
Thread Starter
Registered User
Joined: Jul 1999
Posts: 211
From: craplanta ga
They havent said anything about the cams as of yet..I did look into the ford stuff but i need to build what i have lying around the house.. Friom what i have to use is a 3.50 stroke crank, 6" eagle H beams, a filled 350 block and some valvetrain components.Or refreshing my Lt1 (almost the same internals) with rings and bearings to go at it..Either way the intake will be a 2925 edelbrock with a turtle expoxied in it..
The headers i will be building myself since the engine is probally going into a non chevy.
The headers i will be building myself since the engine is probally going into a non chevy.
Registered User
Joined: Nov 2001
Posts: 2,985
From: In a house by the bay
Originally posted by LT1 1980 malibu
so since you spojke from your experence i take it that you have used a large valve on a vortec or lt1 head????????As you put it..
so since you spojke from your experence i take it that you have used a large valve on a vortec or lt1 head????????As you put it..
Back in the early 70's we were trying larger exhaust valves with nitrous engines. Thought that might be the key to the kingdom... what we learned is that working the exhaust port (when allowed) is worth alot more for the effort. That and getting the exhaust valve timing correct. I don't discount the theory of using a larger valve but then again, we go back to the rule book and it becomes a moot point.
If the LTx or Vortec head didn't accept a 1.625 valve then it'd be the first head I've ever seen that wouldn't. We were trying em on 292s, 186s, 041s, whatever we could get are hands on.... so the question of physically fitting becomes obvious.
-Mindgame
Banned
Joined: Oct 2002
Posts: 6,518
Originally posted by LT1 1980 malibu
Either way the intake will be a 2925 edelbrock with a turtle expoxied in it..
Either way the intake will be a 2925 edelbrock with a turtle expoxied in it..
"1.21 INTAKE MANIFOLD
INTAKE MANIFOLD: Cast aluminum, single carburetor type intake manifolds with a common plenum required for all combinations. Intake manifold must be commercially available and mass-produced. Porting or port-matching prohibited. Welding or epoxy on any part of inside, outside, or plenum of intake prohibited. Carburetor spacers limited to a maximum thickness of 2". Tunnel rams of all types prohibited."
Last edited by SStrokerAce; Jul 5, 2003 at 08:34 PM.
Banned
Joined: Oct 2002
Posts: 6,518
Game,
We might as well just talk up this category reguardless. It's pretty interesting to look at.
Since you have to work with what they allow you to do here, looking at the other makes is something to think about.
In any contest, the first thing I look at is the heads.
Edelbrock E-Tec's look to be the better Chevy choice, but a Vortec is pretty good also.
The Brodix ST 5.0's are the Vortec equivalent for the Fords, and the Edelbrock Perf RPM's look good there too, they also come with the smallest chambers to start with and that's good when there is a flat top rule. The 4bbl Clevelands are not allowed so that's actually good so you don't have to convert the heads to a Windsor style block.
The Edelbrock Perf RPM 340's are pretty nice too. They seem to have the best flow of all the heads.
Now the big question is on the heads, which one has the biggest min cross sectional area? When you are getting 650-700hp with N2O out of a 350-385cube engine you need a much bigger head than they give you here to work with.
So then you have to look at the rules, the $3,000 claim and the pluses and minuses of the engines.
The Chevy is the cheapest, but I don't think it's the best one here.
The Ford has the compression advantage with the smallest chambers, 2nd in pricing and maybe not the best manifolds.
The Mopar has the best heads, you can change the lifter bore angles, a intake on par with the Chevy but it costs the most to build.
Then there are all the other choices. How big do you want to make your engine? How do you get a cheap advantage in the parts they let you work with?
The N2O shot is about 150Hp with that .063 jet size right, that's my guess at least.
Bret
We might as well just talk up this category reguardless. It's pretty interesting to look at.
Since you have to work with what they allow you to do here, looking at the other makes is something to think about.
In any contest, the first thing I look at is the heads.
Edelbrock E-Tec's look to be the better Chevy choice, but a Vortec is pretty good also.
The Brodix ST 5.0's are the Vortec equivalent for the Fords, and the Edelbrock Perf RPM's look good there too, they also come with the smallest chambers to start with and that's good when there is a flat top rule. The 4bbl Clevelands are not allowed so that's actually good so you don't have to convert the heads to a Windsor style block.
The Edelbrock Perf RPM 340's are pretty nice too. They seem to have the best flow of all the heads.
Now the big question is on the heads, which one has the biggest min cross sectional area? When you are getting 650-700hp with N2O out of a 350-385cube engine you need a much bigger head than they give you here to work with.
So then you have to look at the rules, the $3,000 claim and the pluses and minuses of the engines.
The Chevy is the cheapest, but I don't think it's the best one here.
The Ford has the compression advantage with the smallest chambers, 2nd in pricing and maybe not the best manifolds.
The Mopar has the best heads, you can change the lifter bore angles, a intake on par with the Chevy but it costs the most to build.
Then there are all the other choices. How big do you want to make your engine? How do you get a cheap advantage in the parts they let you work with?
The N2O shot is about 150Hp with that .063 jet size right, that's my guess at least.
Bret
Registered User
Joined: Nov 2001
Posts: 2,985
From: In a house by the bay
First a big thumbs up to Chris B.
Hell, I got it with that explanation and it's been a loooong time since chemistry for me. Very well put.
I'm 'game for that discussion Bret.
I had to read the rules before having any kind of intelligent conversation about it and even then... I may have missed a few things in my skim-read. So I apologize before hand if any mistakes are made...
Engine choice.....
For me, I'd still have to go with a chevy, a mopar 360 as my second choice and ford's windsor would come in third.
There are some nice things about mopar small blocks, .904 lifters, shaft rockers (early model), the ability to bore the 71-74 360 blocks .100 over (for 4.1") without a hitch.... 9.6" decks, 6.123 rods.
Only thing is, the bore capability doesn't help us, because of that killer "over 3250 lb" weight penalty. That's a real sticky one there. So I'd stick to building a ~3.5" stroke motor. The mopar's .904 tappet is also nice but we can't really use it to any advantage with the lift limitations.... so I say go Chevy, even though I like the mopar choice.... actually it'd be a toss up for me.
The ford boys will have the GT40 head to work with and it's a nice one, but I'm not to keen on fords. Not for this competition anyways.
As cylinder heads go, the choices for the sbc are not really well known to me. I'd want to consult with a builder who has a bit of experience with them. Chances are, there's a slight advantage from one to the other but it may not be reflected in flow numbers alone. With a nitrous-biased engine, the combustion chamber and exhaust port will probably play a bigger part than anything else IMO.
Which brings up the things that I think will make the difference..... the fuel/nitrous delivery (the carb) and the suspension setup. I'd have a talk with Patrick James at Pro Systems about the carb and have him work his magic on it..... "no annular boosters" which is a pity, but the fuel curve is where it's at either way. The fastest guys IMO are gonna be the ones who've worked the carb to perform well with the nitrous.
It's not gonna be any one thing for an engine like this. Just a combination of little things and getting all the power to the ground in the most efficient manner. Done right, high 9's shouldn't be a problem but look at the payout for the class..... You aint gonna be doing it for the money.... all for the love.
-Mindgame
Hell, I got it with that explanation and it's been a loooong time since chemistry for me. Very well put.
Originally posted by SStrokerAce
Game,
We might as well just talk up this category reguardless. It's pretty interesting to look at.
Since you have to work with what they allow you to do here, looking at the other makes is something to think about.
In any contest, the first thing I look at is the heads.
Edelbrock E-Tec's look to be the better Chevy choice, but a Vortec is pretty good also.
The Brodix ST 5.0's are the Vortec equivalent for the Fords, and the Edelbrock Perf RPM's look good there too, they also come with the smallest chambers to start with and that's good when there is a flat top rule. The 4bbl Clevelands are not allowed so that's actually good so you don't have to convert the heads to a Windsor style block.
The Edelbrock Perf RPM 340's are pretty nice too. They seem to have the best flow of all the heads.
Now the big question is on the heads, which one has the biggest min cross sectional area? When you are getting 650-700hp with N2O out of a 350-385cube engine you need a much bigger head than they give you here to work with.
So then you have to look at the rules, the $3,000 claim and the pluses and minuses of the engines.
The Chevy is the cheapest, but I don't think it's the best one here.
The Ford has the compression advantage with the smallest chambers, 2nd in pricing and maybe not the best manifolds.
The Mopar has the best heads, you can change the lifter bore angles, a intake on par with the Chevy but it costs the most to build.
Then there are all the other choices. How big do you want to make your engine? How do you get a cheap advantage in the parts they let you work with?
The N2O shot is about 150Hp with that .063 jet size right, that's my guess at least.
Bret
Game,
We might as well just talk up this category reguardless. It's pretty interesting to look at.
Since you have to work with what they allow you to do here, looking at the other makes is something to think about.
In any contest, the first thing I look at is the heads.
Edelbrock E-Tec's look to be the better Chevy choice, but a Vortec is pretty good also.
The Brodix ST 5.0's are the Vortec equivalent for the Fords, and the Edelbrock Perf RPM's look good there too, they also come with the smallest chambers to start with and that's good when there is a flat top rule. The 4bbl Clevelands are not allowed so that's actually good so you don't have to convert the heads to a Windsor style block.
The Edelbrock Perf RPM 340's are pretty nice too. They seem to have the best flow of all the heads.
Now the big question is on the heads, which one has the biggest min cross sectional area? When you are getting 650-700hp with N2O out of a 350-385cube engine you need a much bigger head than they give you here to work with.
So then you have to look at the rules, the $3,000 claim and the pluses and minuses of the engines.
The Chevy is the cheapest, but I don't think it's the best one here.
The Ford has the compression advantage with the smallest chambers, 2nd in pricing and maybe not the best manifolds.
The Mopar has the best heads, you can change the lifter bore angles, a intake on par with the Chevy but it costs the most to build.
Then there are all the other choices. How big do you want to make your engine? How do you get a cheap advantage in the parts they let you work with?
The N2O shot is about 150Hp with that .063 jet size right, that's my guess at least.
Bret
I had to read the rules before having any kind of intelligent conversation about it and even then... I may have missed a few things in my skim-read. So I apologize before hand if any mistakes are made...
Engine choice.....
For me, I'd still have to go with a chevy, a mopar 360 as my second choice and ford's windsor would come in third.
There are some nice things about mopar small blocks, .904 lifters, shaft rockers (early model), the ability to bore the 71-74 360 blocks .100 over (for 4.1") without a hitch.... 9.6" decks, 6.123 rods.
Only thing is, the bore capability doesn't help us, because of that killer "over 3250 lb" weight penalty. That's a real sticky one there. So I'd stick to building a ~3.5" stroke motor. The mopar's .904 tappet is also nice but we can't really use it to any advantage with the lift limitations.... so I say go Chevy, even though I like the mopar choice.... actually it'd be a toss up for me.
The ford boys will have the GT40 head to work with and it's a nice one, but I'm not to keen on fords. Not for this competition anyways.
As cylinder heads go, the choices for the sbc are not really well known to me. I'd want to consult with a builder who has a bit of experience with them. Chances are, there's a slight advantage from one to the other but it may not be reflected in flow numbers alone. With a nitrous-biased engine, the combustion chamber and exhaust port will probably play a bigger part than anything else IMO.
Which brings up the things that I think will make the difference..... the fuel/nitrous delivery (the carb) and the suspension setup. I'd have a talk with Patrick James at Pro Systems about the carb and have him work his magic on it..... "no annular boosters" which is a pity, but the fuel curve is where it's at either way. The fastest guys IMO are gonna be the ones who've worked the carb to perform well with the nitrous.
It's not gonna be any one thing for an engine like this. Just a combination of little things and getting all the power to the ground in the most efficient manner. Done right, high 9's shouldn't be a problem but look at the payout for the class..... You aint gonna be doing it for the money.... all for the love.
-Mindgame
Banned
Joined: Oct 2002
Posts: 6,518
Originally posted by Mindgame
I'm 'game for that discussion Bret.
I had to read the rules before having any kind of intelligent conversation about it and even then... I may have missed a few things in my skim-read. So I apologize before hand if any mistakes are made...
Engine choice.....
For me, I'd still have to go with a chevy, a mopar 360 as my second choice and ford's windsor would come in third.
There are some nice things about mopar small blocks, .904 lifters, shaft rockers (early model), the ability to bore the 71-74 360 blocks .100 over (for 4.1") without a hitch.... 9.6" decks, 6.123 rods.
Only thing is, the bore capability doesn't help us, because of that killer "over 3250 lb" weight penalty. That's a real sticky one there. So I'd stick to building a ~3.5" stroke motor. The mopar's .904 tappet is also nice but we can't really use it to any advantage with the lift limitations.... so I say go Chevy, even though I like the mopar choice.... actually it'd be a toss up for me.
The ford boys will have the GT40 head to work with and it's a nice one, but I'm not to keen on fords. Not for this competition anyways.
As cylinder heads go, the choices for the sbc are not really well known to me. I'd want to consult with a builder who has a bit of experience with them. Chances are, there's a slight advantage from one to the other but it may not be reflected in flow numbers alone. With a nitrous-biased engine, the combustion chamber and exhaust port will probably play a bigger part than anything else IMO.
Which brings up the things that I think will make the difference..... the fuel/nitrous delivery (the carb) and the suspension setup. I'd have a talk with Patrick James at Pro Systems about the carb and have him work his magic on it..... "no annular boosters" which is a pity, but the fuel curve is where it's at either way. The fastest guys IMO are gonna be the ones who've worked the carb to perform well with the nitrous.
It's not gonna be any one thing for an engine like this. Just a combination of little things and getting all the power to the ground in the most efficient manner. Done right, high 9's shouldn't be a problem but look at the payout for the class..... You aint gonna be doing it for the money.... all for the love.
-Mindgame
I'm 'game for that discussion Bret.
I had to read the rules before having any kind of intelligent conversation about it and even then... I may have missed a few things in my skim-read. So I apologize before hand if any mistakes are made...
Engine choice.....
For me, I'd still have to go with a chevy, a mopar 360 as my second choice and ford's windsor would come in third.
There are some nice things about mopar small blocks, .904 lifters, shaft rockers (early model), the ability to bore the 71-74 360 blocks .100 over (for 4.1") without a hitch.... 9.6" decks, 6.123 rods.
Only thing is, the bore capability doesn't help us, because of that killer "over 3250 lb" weight penalty. That's a real sticky one there. So I'd stick to building a ~3.5" stroke motor. The mopar's .904 tappet is also nice but we can't really use it to any advantage with the lift limitations.... so I say go Chevy, even though I like the mopar choice.... actually it'd be a toss up for me.
The ford boys will have the GT40 head to work with and it's a nice one, but I'm not to keen on fords. Not for this competition anyways.
As cylinder heads go, the choices for the sbc are not really well known to me. I'd want to consult with a builder who has a bit of experience with them. Chances are, there's a slight advantage from one to the other but it may not be reflected in flow numbers alone. With a nitrous-biased engine, the combustion chamber and exhaust port will probably play a bigger part than anything else IMO.
Which brings up the things that I think will make the difference..... the fuel/nitrous delivery (the carb) and the suspension setup. I'd have a talk with Patrick James at Pro Systems about the carb and have him work his magic on it..... "no annular boosters" which is a pity, but the fuel curve is where it's at either way. The fastest guys IMO are gonna be the ones who've worked the carb to perform well with the nitrous.
It's not gonna be any one thing for an engine like this. Just a combination of little things and getting all the power to the ground in the most efficient manner. Done right, high 9's shouldn't be a problem but look at the payout for the class..... You aint gonna be doing it for the money.... all for the love.
-Mindgame
BTW nice sig, I almost have to say that's better than the 568rwhp one!
The 360 is a great choice, but the dam $3,000 claimer is gonna kill you. I liked it the most because of the Edel-Performer RPM 340 heads flow the best out of all the choices. The .904 lifter is always nice, but you can never find a use for it here. Now the 4.100 bore is not that bad, actually it could be a big help. 385 cube limit but 365 w/out the weight penalty. So offset grind that crank from 3.580" to 3.460" with a 2.000" Chevy Rod and make it that large 4.1" bore and you are just over 365 cubes. Not like it's going to need a over-bore these things are time bombs. The crank will probably break before the rods or pistons go.
Now the Ford and Chevy are about the same for me since I have a 351 W Block and Crank sitting right here vs a 350 Chevy and stock crank. (Which BTW a Scat 9000 replacement looks really good here)
The Ford with that beefy crank (3.00" main bearings for the other guys reading this) and large rod journals allows you to do whatever you want with it. Obviously I like Chevy Rods here too. The things that I do like on the Ford are the small chamber heads, even though you deck the snot out of them you still start with the smallest chambers, therefore the highest achiveable compression with the flatop rule and 20deg valve reliefs. One more perk I like is the front mount distributor so I can push the engine back to the firewall. Some of the Ford heads flow really well and with a slightly shorter port give you a little more cross sectional & volume(since all the volumes are about 170cc). This leads us into heads........
The valve job, the blending of it and venturi size are huge here, that leaves us with worring about the cross sectional area in the rest of the port. Which unless we have the heads in fron of us we don't get to look at.
So now if you look at these head flow numbers (not that it's the only factor) pick which one you want to work with:
Head A: Head B: Head C: Head D:
.300 188/142 .300 183/142 .300 177/138 .300 190/137
.400 232/171 .400 219/163 .400 215/169 .400 227/151
.500 249/183 .500 251/170 .500 240/180 .500 239/160
(BTW the .100-.200 are all about the same, and the VJ will change most of them anyways)
All of these heads are 170cc, with a 2.02 intake valve and 1.60exh valve.
Obviously Head A is the best on both sides of the equation, it's the dam Mopar head with 18deg valve angles. $3K for a long block with these heads! Good luck.
Head D is second best on intake flow here, but it sucks on exahust flow which is not good for N2O.
So that leaves heads B & C which are pretty close to a tie, but head B is most likely going to give you the most constant port cross section and larger min cross sectional area and better cooling because there are no siamese exhaust ports. (it's the SBF head, the other 2 are Chevy Heads)
The Chevy setup, yep it's the cheapest. I just see another 15-20 ft lbs average from 4000-7000 with the other setups, so it just doesn't seem like the best way to go, and I'm a Chevy Guy. I'd probably have a 365 cube SBC sitting on the sidelines ready to go if I euchred the other engine.
The carb is obviously important here but for a $500 claimer it's kind of hard to see a carb go. I wish it was a $700 claimer, but it's not so you have to take the hit somewhere.
Suspension, car choice and setup are all huge, but since you can swap engines across brands it makes all the choices fun. I'd like a G or early A body GM car with the 4 link setup to start with. Then again a light car like a Nova or Vega even though I don't like the suspension as much can be balanced out better. Then we get into the Ford stuff, but i'd like to run a pre 74 car for the 50 lbs weight break too so a Fox Stang is not my first choice.
Your turn Game.
http://www.fasteststreetcar.com/2003/rules/cheapstreet.html
Bret
Banned
Joined: Oct 2002
Posts: 6,518
Originally posted by EricTheBald
2) There is another mechanism at work here that I am missing, don't understand, or am unaware of.
Because otherwise, it makes NO SENSE that the intake needs a bigger "pipe" than the exhaust.
So what's the deal? [/B]
2) There is another mechanism at work here that I am missing, don't understand, or am unaware of.
Because otherwise, it makes NO SENSE that the intake needs a bigger "pipe" than the exhaust.
So what's the deal? [/B]
Why does the Intake port need to be bigger than the exhaust port? Or Intake valve vs Exhaust valve.
The pressures here are most of the reason why. As I posted above the pressure differences from the cylinder to the respective ports is greatly different. The intake port pressure vs the cylinder pressure in comparison to the cylinder pressure after combustion vs the exhaust port pressure is much different. Fluids move from high pressure to low pressure, that's why A/F enters the cylinder in the first place and then exits the cylinder once combustion has happened.
You could make the two ports equal in size, but that doesn't use the space very efficently.
Bret
Registered User
Joined: Nov 2001
Posts: 2,985
From: In a house by the bay
Yeah, I like the new sig better too, thanks Bret.
On the chemistry... well it's gone well beyond that IMO. I'll call PETA in on this one..... dead horses have rights too.
I'll be back on the Pro cheap stuff after work.
-Mindgame
On the chemistry... well it's gone well beyond that IMO. I'll call PETA in on this one..... dead horses have rights too.
I'll be back on the Pro cheap stuff after work.
-Mindgame
Registered User
Joined: Oct 2002
Posts: 2,931
From: Upstate NY
Originally posted by Mindgame
On the chemistry... well it's gone well beyond that IMO. I'll call PETA in on this one..... dead horses have rights too.
I'll be back on the Pro cheap stuff after work.
-Mindgame
On the chemistry... well it's gone well beyond that IMO. I'll call PETA in on this one..... dead horses have rights too.
I'll be back on the Pro cheap stuff after work.
-Mindgame
Cheap Street: Is 4wd/awd prohibited? I couldn't find anything that outlaws it. I see a Syclone derivative with a SBC or even Bret's SBF. Since 10 inch tires probably limit how much N2O you can use at launch with RWD, the torque split with the Borg-Warner 4472 AWD transfer case appeals to me. 35% front, but varies with wheelspin. LPE boosted current generation AWD pickup at 3800+ driver cuts 1.58 60 ft times on street tires (not even DRs).
Rules legal '90 S10/S15 might get down to min weight.
It's all about ET, so the 50 lb weight break for trucks can't hurt.
I believe 700 hp Syclones are now running quicker than the Cheap Street record of 10.47.
My $.02
Administrator
Joined: Nov 1998
Posts: 71,094
From: Hell was full so they sent me to NJ
This thread is so far from its initial intent that it is useless. Unfortunatley, one person decided to turn it into his personal platform for debate.
Closing.
I will try and split out the important stuff, and preserve that, then dump the rest.
FOLLOWUP: Split successful. PLEASE limit discussion to the original topic.
Fred
Closing.
I will try and split out the important stuff, and preserve that, then dump the rest.
FOLLOWUP: Split successful. PLEASE limit discussion to the original topic.
Fred
Last edited by Injuneer; Jul 7, 2003 at 04:48 PM.
Registered User
Joined: Nov 2001
Posts: 2,985
From: In a house by the bay
Originally posted by SStrokerAce
I'm out of the whole mass/volume deal due to you probably need some chemistry education to understand it.
BTW nice sig, I almost have to say that's better than the 568rwhp one!
The 360 is a great choice, but the dam $3,000 claimer is gonna kill you. I liked it the most because of the Edel-Performer RPM 340 heads flow the best out of all the choices. The .904 lifter is always nice, but you can never find a use for it here. Now the 4.100 bore is not that bad, actually it could be a big help. 385 cube limit but 365 w/out the weight penalty. So offset grind that crank from 3.580" to 3.460" with a 2.000" Chevy Rod and make it that large 4.1" bore and you are just over 365 cubes. Not like it's going to need a over-bore these things are time bombs. The crank will probably break before the rods or pistons go.
Now the Ford and Chevy are about the same for me since I have a 351 W Block and Crank sitting right here vs a 350 Chevy and stock crank. (Which BTW a Scat 9000 replacement looks really good here)
The Ford with that beefy crank (3.00" main bearings for the other guys reading this) and large rod journals allows you to do whatever you want with it. Obviously I like Chevy Rods here too. The things that I do like on the Ford are the small chamber heads, even though you deck the snot out of them you still start with the smallest chambers, therefore the highest achiveable compression with the flatop rule and 20deg valve reliefs. One more perk I like is the front mount distributor so I can push the engine back to the firewall. Some of the Ford heads flow really well and with a slightly shorter port give you a little more cross sectional & volume(since all the volumes are about 170cc). This leads us into heads........
The valve job, the blending of it and venturi size are huge here, that leaves us with worring about the cross sectional area in the rest of the port. Which unless we have the heads in fron of us we don't get to look at.
So now if you look at these head flow numbers (not that it's the only factor) pick which one you want to work with:
Head A: Head B: Head C: Head D:
.300 188/142 .300 183/142 .300 177/138 .300 190/137
.400 232/171 .400 219/163 .400 215/169 .400 227/151
.500 249/183 .500 251/170 .500 240/180 .500 239/160
(BTW the .100-.200 are all about the same, and the VJ will change most of them anyways)
All of these heads are 170cc, with a 2.02 intake valve and 1.60exh valve.
Obviously Head A is the best on both sides of the equation, it's the dam Mopar head with 18deg valve angles. $3K for a long block with these heads! Good luck.
Head D is second best on intake flow here, but it sucks on exahust flow which is not good for N2O.
So that leaves heads B & C which are pretty close to a tie, but head B is most likely going to give you the most constant port cross section and larger min cross sectional area and better cooling because there are no siamese exhaust ports. (it's the SBF head, the other 2 are Chevy Heads)
The Chevy setup, yep it's the cheapest. I just see another 15-20 ft lbs average from 4000-7000 with the other setups, so it just doesn't seem like the best way to go, and I'm a Chevy Guy. I'd probably have a 365 cube SBC sitting on the sidelines ready to go if I euchred the other engine.
The carb is obviously important here but for a $500 claimer it's kind of hard to see a carb go. I wish it was a $700 claimer, but it's not so you have to take the hit somewhere.
Suspension, car choice and setup are all huge, but since you can swap engines across brands it makes all the choices fun. I'd like a G or early A body GM car with the 4 link setup to start with. Then again a light car like a Nova or Vega even though I don't like the suspension as much can be balanced out better. Then we get into the Ford stuff, but i'd like to run a pre 74 car for the 50 lbs weight break too so a Fox Stang is not my first choice.
Your turn Game.
http://www.fasteststreetcar.com/2003/rules/cheapstreet.html
Bret
I'm out of the whole mass/volume deal due to you probably need some chemistry education to understand it.
BTW nice sig, I almost have to say that's better than the 568rwhp one!
The 360 is a great choice, but the dam $3,000 claimer is gonna kill you. I liked it the most because of the Edel-Performer RPM 340 heads flow the best out of all the choices. The .904 lifter is always nice, but you can never find a use for it here. Now the 4.100 bore is not that bad, actually it could be a big help. 385 cube limit but 365 w/out the weight penalty. So offset grind that crank from 3.580" to 3.460" with a 2.000" Chevy Rod and make it that large 4.1" bore and you are just over 365 cubes. Not like it's going to need a over-bore these things are time bombs. The crank will probably break before the rods or pistons go.
Now the Ford and Chevy are about the same for me since I have a 351 W Block and Crank sitting right here vs a 350 Chevy and stock crank. (Which BTW a Scat 9000 replacement looks really good here)
The Ford with that beefy crank (3.00" main bearings for the other guys reading this) and large rod journals allows you to do whatever you want with it. Obviously I like Chevy Rods here too. The things that I do like on the Ford are the small chamber heads, even though you deck the snot out of them you still start with the smallest chambers, therefore the highest achiveable compression with the flatop rule and 20deg valve reliefs. One more perk I like is the front mount distributor so I can push the engine back to the firewall. Some of the Ford heads flow really well and with a slightly shorter port give you a little more cross sectional & volume(since all the volumes are about 170cc). This leads us into heads........
The valve job, the blending of it and venturi size are huge here, that leaves us with worring about the cross sectional area in the rest of the port. Which unless we have the heads in fron of us we don't get to look at.
So now if you look at these head flow numbers (not that it's the only factor) pick which one you want to work with:
Head A: Head B: Head C: Head D:
.300 188/142 .300 183/142 .300 177/138 .300 190/137
.400 232/171 .400 219/163 .400 215/169 .400 227/151
.500 249/183 .500 251/170 .500 240/180 .500 239/160
(BTW the .100-.200 are all about the same, and the VJ will change most of them anyways)
All of these heads are 170cc, with a 2.02 intake valve and 1.60exh valve.
Obviously Head A is the best on both sides of the equation, it's the dam Mopar head with 18deg valve angles. $3K for a long block with these heads! Good luck.
Head D is second best on intake flow here, but it sucks on exahust flow which is not good for N2O.
So that leaves heads B & C which are pretty close to a tie, but head B is most likely going to give you the most constant port cross section and larger min cross sectional area and better cooling because there are no siamese exhaust ports. (it's the SBF head, the other 2 are Chevy Heads)
The Chevy setup, yep it's the cheapest. I just see another 15-20 ft lbs average from 4000-7000 with the other setups, so it just doesn't seem like the best way to go, and I'm a Chevy Guy. I'd probably have a 365 cube SBC sitting on the sidelines ready to go if I euchred the other engine.
The carb is obviously important here but for a $500 claimer it's kind of hard to see a carb go. I wish it was a $700 claimer, but it's not so you have to take the hit somewhere.
Suspension, car choice and setup are all huge, but since you can swap engines across brands it makes all the choices fun. I'd like a G or early A body GM car with the 4 link setup to start with. Then again a light car like a Nova or Vega even though I don't like the suspension as much can be balanced out better. Then we get into the Ford stuff, but i'd like to run a pre 74 car for the 50 lbs weight break too so a Fox Stang is not my first choice.
Your turn Game.
http://www.fasteststreetcar.com/2003/rules/cheapstreet.html
Bret
And I don't have a suspension problem with these cars as my old 65' Nova drag car was a consistent ~1.34 second 60 footer with nothing special next to an underrider bar to control spring wrapup.
Let's not dismiss the mopar just yet though. The 4.1" bore is still enticing. I don't agree with the "time bomb" crank theory as many of these things were reliably turning Richard Petty's race cars in the mid seventies. And if you break this motor... what have you really got in it??
I agree, the mopar has the better cylinder head. That with the big bore gives us piston area and here we're talking nitrous.... PSI, so the more square inch we got, the better IMO. Of course alot of guys are talking this up just like we are. I guess it just comes down to putting the $change$ where the mouth is right.
For an engine builder, that's a promising proposition cause it'd definitely bring business to your doors. For me, it just doesn't mean much but it is an interesting class because anyone can play.
The claim thing is a stickler see... the only guys who can make a claim are those qualifying in the top 5 (I believe) and the chances are that no claims will be made (there have been none so far as I can tell). One of the quickest guys, holding the points title right now, is Jeremy Taylor. He's running a Nova and ironically enough, he's running a Pro Systems nitrous carb.
For the nitrous guys, like I said before, there's alot to be had in the carb. There are also some fudging area with the nitrous delivery. The guy who dominates is definitely gonna be the one tip-toeing on the edge of legality. Compression is only a domed piston away. I know alot of guys don't like domes but for a race car.... you have a lot less worry.
Disorganized thoughts and my apologies for that but I'll be back later to cover the stuff I'm missing.
-Mindgame