350 or 400 mains

Which one is better to get in a WP block if you were building a 427 sbc? Just trying to check out som prices of different things while i'm deciding what to do. Also would it be better to go with a WP or a dart block..any advantages to either?

Which one is better to get in a WP block if you were building a 427 sbc? Just trying to check out som prices of different things while i'm deciding what to do. Also would it be better to go with a WP or a dart block..any advantages to either?

350=less friction=less heat.

any opinion on the dart or WP block? thanks for the help

any opinion on the dart or WP block? thanks for the help

No,it's whatever one fits the app best.The 'Little M" is a good one.
If I were going to build a customer a 427,I would go with the biggest bore(4.155) and shortest rod and shortest stroke I could to make it a 427.The largest heads I could afford and the best intake.Cam would depend on the head selection,and compression=DCR.

What you trying to do here? Depends on the power level, stroke and rod journal in my choice of 327/350/400 mains.

Bret

heres what i thought the common way to make the 427 was: 4.125" bore with the 4" stroke on a sbc 6" rod. I already have some h beams w/ the arp l19 bolts that are 6" long so i was planning on using them with a 4" stroke crank and then picking up some pistons with the correct pin height, compression, etc. I plan on bolting on some sb2.2 heads that have been ported and are flowing in the the 430 cfm...intake will either be the spider intake or a sheet metal..not sure yet. Also planned on running the iron block since saving a minimal amount of weight didn't really justify me purchasing an alum block. Let me know what you'll think about this...

I like GM blocks....
Second choice would be Dart
World products would be last.

I personally like using a long rod....we have done many back to back dyno comparisons/R&D with our GTA and road race programs, they have all shown that the long rod motors make a flatter-broader torque curve.

heres what i thought the common way to make the 427 was: 4.125" bore with the 4" stroke on a sbc 6" rod. I already have some h beams w/ the arp l19 bolts that are 6" long so i was planning on using them with a 4" stroke crank and then picking up some pistons with the correct pin height, compression, etc. I plan on bolting on some sb2.2 heads that have been ported and are flowing in the the 430 cfm...intake will either be the spider intake or a sheet metal..not sure yet. Also planned on running the iron block since saving a minimal amount of weight didn't really justify me purchasing an alum block. Let me know what you'll think about this...

The dyno test I have done,there is NOT a nickle's worth of difference in a 5.7 to a 6.0 in. rod.In fact ya may loose some HP&TQ with a 6.125"rod and those heads.

Ya don't NEED all the brain damage that comes with an aluminum block.It's completely different when ya are having the machine work done and with the assembly. There are ALL kind's of little TRICKS to do to it.

How much are the bowtie blocks running? Would it be better to run the raised cam location in the block or just stick with the stock location?

How much are the bowtie blocks running? Would it be better to run the raised cam location in the block or just stick with the stock location?

Don't know price but they are spendy.
I would go with the raised cam to clear your crank. There will be special timing chain and distributor.

bowtie blcoks already come machined like the darts? The blocks may be a little spendy but by the time you get all your machine work done the right way, you might as well start with the better block

I already have some h beams w/ the arp l19 bolts that are 6" long so i was planning on using them with a 4" stroke crank ...

BTW a L19 bolt head needs clearancing on a 355, let alone what happens on a 427, that's going to be scary.

BTW Rod Length is a pretty small thing to look at, but it does have uses in situations where you want to grow or shrink a head port in a motor.

Bret

i have already clearanced the l19s in a 383 and know what it takes. in the WP block, WP told me the bolts will clear fine with the 4" stroke but they may have just said that. What is your opinion on the raised cam and which block to go with bret??

I would do the raised cam even though it costs more for lots of reasons.

Bret

dart block work out then?? Can you get the dart block with the bores not finished so that you can hone them to your specs...all the ones i see through summit have finished bores. With the raised cam, you have to run the diff. timing chain set up and do you run a shorter pushrod to compensate for the cam being higher? How much more is the raised cam set up going to run then a normal cam set up? thanks bret and everyone else

dart block work out then?? Can you get the dart block with the bores not finished so that you can hone them to your specs...all the ones i see through summit have finished bores. With the raised cam, you have to run the diff. timing chain set up and do you run a shorter pushrod to compensate for the cam being higher? How much more is the raised cam set up going to run then a normal cam set up? thanks bret and everyone else

If ya had to get the accessories anyway for the LT-1,it would not be but $1-200 more and a screaming set up.
I would get the block that would let me go to close to a 4.150 bore or a tad less,with one more boring left to rebuild.
Those heads will flow ungodly if ya REALLY unshroud the valves.Don't let anybody tell ya .080 is enough,the more ya have the better the air column and more of it into the cyl.

the dart block can be bored to 4.185 maximum. Is there really much difference in boring it 4.125 or 4.150 for the first round? Seems like by boring it out to 4.150, you are limiting yourself to less rebuilds on the block. With the 4.125 it is a 427.43 cubic inches and with the 4.150 bore, you would have 432.629 cubic inch motor. You owuld gain about 6 cubic inches.

the dart block can be bored to 4.185 maximum. Is there really much difference in boring it 4.125 or 4.150 for the first round? Seems like by boring it out to 4.150, you are limiting yourself to less rebuilds on the block. With the 4.125 it is a 427.43 cubic inches and with the 4.150 bore, you would have 432.629 cubic inch motor. You owuld gain about 6 cubic inches.

Only for valve unshrouding.Its not the 6CID.

So you think that unshrouding them that much more will make a huge diff. or is it going to be minimal?

So you think that unshrouding them that much more will make a huge diff. or is it going to be minimal?

The more ya have the better.I can't say that it would be a huge difference,but one overbore will last 8-10 years if ya don't blow it up.

Can you put a rough number on the differnce in hp so i can put it in perspective? Or does that all depend on ten million other things?

Can you put a rough number on the differnce in hp so i can put it in perspective? Or does that all depend on ten million other things?

No
But I will site an example:
A guy had a 598?BB and made it a 640? with a .060 smaller bore and the rest in stroke. He used the same heads,cam,intake. The car was running 8.60's and slowed down .3 tenths.He changed cam's and that didn't help. He talked to other engine builder's and they all scratched their head.
We got to talking and determined it was valve shrouding.He bored it to the other block size and used the same style pistons,except .060 larger,and changed nothing else just to see.
The car went a 8.26 it's first pass after the bore job and has since gone quicker.

So valve shrouding IS important and everybody thought the bore size of that BB wouldn't shroud the valve, but it did. The extra few cubes didn't do it either.

Alright that def. puts it in perspective then. I didn't realize that the valve shrouding would be bad since the heads were originally set up for a 4.125 bore. I guess the last question in concern tot he block is should i keep it stock deck height or get the taller deck that dart offers? thanks for all the help.

Alright that def. puts it in perspective then. I didn't realize that the valve shrouding would be bad since the heads were originally set up for a 4.125 bore. I guess the last question in concern tot he block is should i keep it stock deck height or get the taller deck that dart offers? thanks for all the help.

Stock.The tall deck get's REAL expensive to make it do what it's suppose to do HP wise. Automatic new intake and header's and a bunch more.

www.summitracing.com part number DRT-31121211


so that looks like the block for the application then? wheres the best place to get it so i don't have to weight till august 16?

No
But I will site an example:
A guy had a 598?BB and made it a 640? with a .060 smaller bore and the rest in stroke. He used the same heads,cam,intake. The car was running 8.60's and slowed down .3 tenths.He changed cam's and that didn't help. He talked to other engine builder's and they all scratched their head.
We got to talking and determined it was valve shrouding.He bored it to the other block size and used the same style pistons,except .060 larger,and changed nothing else just to see.
The car went a 8.26 it's first pass after the bore job and has since gone quicker.

So valve shrouding IS important and everybody thought the bore size of that BB wouldn't shroud the valve, but it did. The extra few cubes didn't do it either.

So the heads were cut for the big bore the first time? Make sense that he slowed down. OTOH you can make heads work on a smaller bore, al la LS1... only problem with those things is the heads flow like mad but make power like crap for the cfm. 330cfm should make 700hp if done right, not 550-600hp.

I'm still a fan of bigger bores. Actually a old GM engineer wrote in to Hot Rod about the Bore vs. Stroke story and told the tale of the "mystery motor" development and the shrinking of the 396 bore to use the common crank with the 427 and they lost HP on the motors, once they motored them to find frictional losses TA DA! there was all the HP losses... sometimes it's frictional losses sometimes (especially on BBC's it's bore shrouding issues)

Bret

so from your point of view bret, would you bore the motor over to 4.150" or just leave it at 4.125 and be able to get more life out of the block in case you need it down the road? Just trying to get everyones point of view. Also if you'll could post up some link for where to get the block and let me know if thats the correct part number. thanks

So the heads were cut for the big bore the first time? Make sense that he slowed down. OTOH you can make heads work on a smaller bore, al la LS1... only problem with those things is the heads flow like mad but make power like crap for the cfm. 330cfm should make 700hp if done right, not 550-600hp.

I'm still a fan of bigger bores. Actually a old GM engineer wrote in to Hot Rod about the Bore vs. Stroke story and told the tale of the "mystery motor" development and the shrinking of the 396 bore to use the common crank with the 427 and they lost HP on the motors, once they motored them to find frictional losses TA DA! there was all the HP losses... sometimes it's frictional losses sometimes (especially on BBC's it's bore shrouding issues)

Bret


From looking at his heads the chambers didn't appear to have been laid back to the edge of the bigger bore. IMO it all had to do with the distance between the valve and the bore and I feel that was proven.

Got a first hand idea on what the 330CFM will make.That won't make 700 IF everything else isn't dead nuts.

From looking at his heads the chambers didn't appear to have been laid back to the edge of the bigger bore. IMO it all had to do with the distance between the valve and the bore and I feel that was proven.

Got a first hand idea on what the 330CFM will make.That won't make 700 IF everything else isn't dead nuts.

.060 on a bore is a big amount either way.... It would have been interesting to see the flow on the bench with both bores to see if there was a difference as well.

As for the LS1 heads.... they ain't gonna make 700hp out of 330cfm unless you spend lots of money on the R&D of the port... only a few guys out there that can do that too.

Bret

.060 on a bore is a big amount either way.... It would have been interesting to see the flow on the bench with both bores to see if there was a difference as well.

As for the LS1 heads.... they ain't gonna make 700hp out of 330cfm unless you spend lots of money on the R&D of the port... only a few guys out there that can do that too.

Bret


I was speaking my engine .

I was speaking my engine .

lol

I was thinking about a stock cube LS1 I'm working on lol

Bret

lol

I was thinking about a stock cube LS1 I'm working on lol

Bret

OOOKKKK

lol

I was thinking about a stock cube LS1 I'm working on lol

Bret

Here is some HP!!!!!


A REPORT said that scientists at Seikei and Aichi universities have discovered a lubricant that promises near to zero friction.

According to the report, in today's Nikkei Business Daily, the multilayer material consists of arrays of ball shaped fullerene molecules, between a sandwich of ultra thin films of graphite.

The graphite layers are around 1.3 nanometres, says the paper, with the fullerene balls about .7 nanometres in diameter, with molecular forces keeping the balls spaced evenly.

The report claims that when pressure is applied, it operates at a friction force of less than .4 nanonewtons - that compares to top lubricants exerting one nanonewton.

The Nikkei Business Daily reckons that the stuff can be turned into a powder and applied to mechanical parts to extend their active life. µ

Here is some HP!!!!!


A REPORT said that scientists at Seikei and Aichi universities have discovered a lubricant that promises near to zero friction.

According to the report, in today's Nikkei Business Daily, the multilayer material consists of arrays of ball shaped fullerene molecules, between a sandwich of ultra thin films of graphite.

The graphite layers are around 1.3 nanometres, says the paper, with the fullerene balls about .7 nanometres in diameter, with molecular forces keeping the balls spaced evenly.

The report claims that when pressure is applied, it operates at a friction force of less than .4 nanonewtons - that compares to top lubricants exerting one nanonewton.

The Nikkei Business Daily reckons that the stuff can be turned into a powder and applied to mechanical parts to extend their active life. µ


so about that part number i posted up and where to get the block?? that way i can get it on the way then we can go back to nanotechnology while i wait forever lol

so about that part number i posted up and where to get the block?? that way i can get it on the way then we can go back to nanotechnology while i wait forever lol

I would shop around and see if ya can get it cheaper than Summet
Call Dart,WP,and GMPP they all have similar blocks and see what is to be offered and price and shipping.Ya know the "Let's Make A Deal" story.The shipping could be a deal maker or breaker.As far as quality they mostly are about the same with Dart and GM being a bit better on their finished machine work from what I have seen.

ok cool.....bret you gave me a crazy idea..what about running a single turbo on this 427...opinions?

ok cool.....bret you gave me a crazy idea..what about running a single turbo on this 427...opinions?

OOOOOHHHHHHH 1500HP AAAAHHHHHH

the qustion is would the t88 sitting in the garage be big enough for that??

Probably.

I just did a 355 that has a GT42R attached to it for a street motor.

Bret

the qustion is would the t88 sitting in the garage be big enough for that??

NAAAA
Go whole hog and put a 100MM on it.
1500HP AHHHH. :eek:

Larry, why are you and I on at the same time everynight?

Larry, why are you and I on at the same time everynight?

Same time same station folks--Tune in tomorrow for further adventure of Frick & Frack

LUCKEY I guess :shrug:

The Tappet Brothers? I thought they were Click and Clack?

haha its just going to stay NA and the turbo is going on the eclipse gsx

The Tappet Brothers? I thought they were Click and Clack?

Frick & Frack are the ones that FIX the Click & Clack..

Keep those card's and letter's rolling in folks........ :shrug: