Excellent numbers!!! Makes me wanna dump a 383 into the Trans Am...I may have to remember that in a couple years come motor building time...

 

6spd? auto? converter?

 

Good job gentlemen.

Trey,
Who recommended that you use a billet connecting rod? Second, why did you believe them?

Take care

 

Yeah Ill have to work on the timing...Thanks Dr Mugde. Yeah I could have just recammed and put a M6 in but the rings on the old motor were shot and it was leaking everywhere. Last year I had 325rwhp with my A4, for that price I got a whole new motor and 100+ rwhp. Not too bad. Although I do see where you are coming from.

 

A plug: I drove the car and while I didn't pound on it, it feels very strong. In case anyone isn't a believer in the "short duration/high lift" cam scenario, this combo should help them make up their minds. Also it's a poster child for narrower LSA on an NA combo. Obviously, it's inherently a little misleading to talk about things like LSA in isolation, but those who have been following the cam discussions here will have the right frame of reference.

Nice work, Bret and Matt

Rich Krause

 

peak yes............but area under the curve, i guarantee the 383 owns a heads/cam 350.

 

I've seen a few of the cam discussions on this and other forums and there is no doubt where the misconceptions stem from. I have yet to see a message forum that didn't have it's "experts" who don't actually test and build engines. There in lies the problem.
Normally aspirated small block chevies (those looking to make 1.3hp/cid or better) will always respond best to lobe seperation angles of 112º or less. I actually prefer 108-110... backed by extensive testing and engine development.

Take care

 

I dont know, i also used a forged piston for an NA motor
Luckily someone sold me thier *new* rods for like $400 or so it wasn't that big a deal. All it really did was get me ohhhs and ahhhs from the machine shop and people who've helped me on the car (drop oil pan when i was done, no facilites at school)...


now silly question-

how come phil is making 412rwhp through shorties, tame cam. old and LT1 casting and this 383 is making 433rwhp though full bolt ons...

obviously i'm not attacking or insulting your motor, i myself am PRAYING for 425rwhp (fat chance through a stalled auto) but yo have cubes, LT4 heads, long tubes, and a hand full of gurus. I was talking to Jon about it before. Someone is going to bring it up, might as well be me. Were all thinking it.

What am i missing? I thought this was an auto at first which COMPLETLY flattened me. now i'm just stunned .






I dont know the cam specs on this cam, but i grabbed the 236/242 on a 111 LSA with high lift (.608/.613?). Is this concidered a high lift for its durration? "high lift" is an ohhh-so relative work


Mr. HP-
would you still advise a 108-110 LSA (again not to speak of it in isolation like rich said above) for a vehicle using 3 gears?


anyway,
hope to see you guys soon. my (current, not home ) state sucks as far as tuning goes. If nothing else, i want a ride any i may or may not be able to resist the temptation to hump your fenders

 

For Matt's budget and setup. The KB's were a cheap way to go and also fit the budget.

Why? well the -19cc dish and 50cc chamber gave us about 11:1, which is very conservative, this thing is a 99% street car. Second the hypereutectic pistons has tighter piston to wall clearance and is about as close to a strong "stock" replacement for this setup as you can get. Basically if GM was going to build a HO 383 setup it would be pretty close to this.

Look around here this week, when we become a sponsor you'll see that I have to agree with you on the Forged setup.

Bret

 

Thanks Chuck, belive me it means somthing.

I do have to laugh at the billet rod comment. I totally agree.

Bret

 

Thanks from you too Rich. All of this on a larger than normal intake port too. Talk about the small cam, high lift, big head B.S.

I like 110's alot for LSA but you have to watch yourself with them on EFI street cars. Matt wanted an agressive idle and I wanted a smaller cam so the 110 LSA was a perfect match. I really look more at the Intake Valve Closing point. So things like LSA, advance, duration all play a big part in that. The 110 LSA does help the Dynamic Compression Ratio out though, which is one of the benefits of it that I like.

Bret

 

Trey your point is well taken. First off my first comeback would be the timing. The only thing i know right now is that I have no knock retard. I may have too much but most likely I do not have enough. I myself have not tuned cars on a dyno but a few degrees here and there can make a huge difference from what Im told. In one case something like 40 HP was to be had within a degree either way. So it is possible that I may even see 450rwhp although we wont know until it goes back on the dyno.

Another would be that my cam could be considered even smaller than the ones posted on Phil's site. Infact I know mine is. This car is no doubt a street car. It idles like a dream and feels like it has more vacuume and street manners than my old head cam setup did. Infact I just drove a car with just headers and a hot cam and besides the noise and the obvious difference in power you really couldnt tell a difference in street manners.

Although the cubes play a huge roll were talking 50+ ftlbs of torque over what they have also....cant forget that

In a previous thread discussing the rwhp of strokers the average seemed to be in the 420-440 range for HP and 380-420 for the torque. Some of the figures posted in the thread were

415/379
416/383
410/??? -> A4
390/??? -> Th400
436/??? Jim S. '95Z28
425/??? Injuneer Fred
451/416 INTMD8

INTMD8's numbers were the highest posted and this was with a 250/251 solid roller. My hydraulic isnt anywhere near that. So it looks like its right were its suppossed to be.

A solid roller maybe in the future next year which could make some exceptional numbers.

For now Ill take it. 433 is a handful as it is.

 

I just have to insert this shamelss plug for fred-

his is an NA 425- dont forget his NAWSSS
hes also got a TH400, non-locking converter and 12 bolt sucking up power

his car is a work of art-
i'd hate to be the one figuring out where all those wires and steel braided lines go

 

i dunno about that 40 hp gain within a degree change either way comment... i could see 5 maybe but 40? i have struggled with this timing bs for quite some time now and while i have learned quite a bit about it in the last few weeks.. i still dont know much! but hey man those are some nice numbers for sure so maybe you already have it dialed in. either way, nice work for all those envolved.

i am also a big fan of the smaller cam with a narrow LSA... XE224/230-110 LSA here and i love it!

 

Trey,

It's not silly. For once.

Anyone care to look at the difference in curves from the 383 to the 350? How about 50 ft lbs? And it's there most of the way up. That's a ton. I usually don't see LT1's that are 420 ft lbs and 430hp. That's alot of TQ from a crappy intake manifold. Another thing was to keep the HP peak down, that is going limit some things. Namely HP. If we moved the peak up another 500rpm then it would take more budget to do it right (to not lose TQ) but I could get feaseably another 15-25hp. Droping a Solid Roller in this (which is basically a cam and lifter swap in his motor) will get you there easier.

BTW cubes (as in going to 383 from 350) is not going to make HP. You can make the same HP from a 350 as you can a 383 for the most part on a street engine. Mainly due to the fact that you are using the same parts, which will limit you. In racing, yeah you could gain anywhere from 60-80 hp with the whole engine designed around those extra cubes. On the street that's generally much less.

There are a few things I would like to try on Matt's engine in the valvetrain to gain some more power, but the basic setup is not bad at all. What are they? Those 3 things are most likely not going to be found on the forum for a while, but guys could take a good guess at one of them, the next two probably not. BTW it's not changing the cam specs. One hint is that it's applying some LS1 technology to LT1's. Like I said it's only going to get us to about 450rwhp or so.

Trey, your cam in comparison to Matt's is a monster.

Bret