And?
350 or 400?
Thread Starter
Pro
Joined: Oct 2005
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From: Chicago IL
350 or 400?
Hey guys, I'm going with either a 350 4 bolt main or a 400 4 bolt main engine. We've been leaning towards a 400 for a while, but now my dad heard from some others that we should go with the 350. What would CF recommend? We're looking to get the most power out of it. The vette is going to be a street car. Thanks in advance.
Team Owner
Joined: Aug 2006
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From: Columbia Missouri
Originally Posted by BerniesVette
The 400 gives you more before you start making any mods.
Bernie
Bernie
You can stroke the 350 to 383 or more depending or bore, and the 400 can be bored and built up. I like the torque of the 400, and have learned within the last few days that you can lengthen the rods a touch, use a high duration cam, balance everything, add some good high flow heads, top everything off with a well tuned high CFM carb and get somewhere close to 600 HP.
Race Director
Joined: Dec 1999
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From: Forked River NJ
Originally Posted by Durango_boy
You can stroke the 350 to 383 or more depending or bore, and the 400 can be bored and built up. I like the torque of the 400, and have learned within the last few days that you can lengthen the rods a touch, use a high duration cam, balance everything, add some good high flow heads, top everything off with a well tuned high CFM carb and get somewhere close to 600 HP.
To get 600HP from a 400 you had better have a big roller cam and huge heads. I have driven a 421 SB with 580 HP with AFR 227 heads and a big roller cam and a 950 carb. This was tuned to perfection and it dynoed at 580 HP. A beast of a motor. A well built 400 will get you a tad over 500 HP without going to exotic.
Le Mans Master
Joined: Oct 2001
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From: Wildwood IL
If you haven't purchased a 511 casting 400 4-bolt yet...don't! The 2-bolt 817 or even more desirable but hard to find 2 bolt 509 high tin high nickel blocks are stonger. The 400 is basically a 350 block bored to 4.125. That doesn't leave much "meat" between the cylinders. The 4th main bolt is drilled into that already thin webbing. If your looking for a high RPM 500HP 400ci...a 4-bolt is not gonna stand up. Your better off using a 2 bolt with "splayed caps" on the mains. Many guys here have sucessfully built 2 bolt 400's that are high horsepower high torque screamers.
Hope I can join that club when mine is done
Eddie
Hope I can join that club when mine is done
Eddie
Racer
Joined: Oct 2000
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From: Houston, Texas
Originally Posted by Durango_boy
You can stroke the 350 to 383 or more depending or bore, and the 400 can be bored and built up. I like the torque of the 400, and have learned within the last few days that you can lengthen the rods a touch, use a high duration cam, balance everything, add some good high flow heads, top everything off with a well tuned high CFM carb and get somewhere close to 600 HP.
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Race Director
Joined: May 2005
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From: Millington Illinois
St. Jude Donor '08-'09
715 Hp 406 Na
http://forums.corvetteforum.com/show....php?t=1492587 600 HP out of a 406 is probably not streetable and won't run on pump gas but it can be done. Properly matched components go a long way to achieving optimum power. If the components are not matched correctly you can actually lose power with an upgrade. Throw a big cam in a stock motor. it will lope nice but a lot of times it will be slower and less streetable. Put huge heads on the same stock motor, same results. 750 DP on the same motor, same results. Falls on it's face at the bottom end. MATCH YOUR COMPONENTS TO COMPLIMENT EACH OTHER THROUGHOUT THE ENGINE!
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Pro
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From: Chicago IL
Originally Posted by Edzred72
If you haven't purchased a 511 casting 400 4-bolt yet...don't! The 2-bolt 817 or even more desirable but hard to find 2 bolt 509 high tin high nickel blocks are stonger. The 400 is basically a 350 block bored to 4.125. That doesn't leave much "meat" between the cylinders. The 4th main bolt is drilled into that already thin webbing. If your looking for a high RPM 500HP 400ci...a 4-bolt is not gonna stand up. Your better off using a 2 bolt with "splayed caps" on the mains. Many guys here have sucessfully built 2 bolt 400's that are high horsepower high torque screamers.
Hope I can join that club when mine is done
Eddie
Hope I can join that club when mine is done
Eddie
Thread Starter
Pro
Joined: Oct 2005
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From: Chicago IL
Originally Posted by 63mako
http://forums.corvetteforum.com/show....php?t=1492587 600 HP out of a 406 is probably not streetable and won't run on pump gas but it can be done. Properly matched components go a long way to achieving optimum power. If the components are not matched correctly you can actually lose power with an upgrade. Throw a big cam in a stock motor. it will lope nice but a lot of times it will be slower and less streetable. Put huge heads on the same stock motor, same results. 750 DP on the same motor, same results. Falls on it's face at the bottom end. MATCH YOUR COMPONENTS TO COMPLIMENT EACH OTHER THROUGHOUT THE ENGINE!
I know about the compliment things, only problem is that my dad bought some 2.02 heads back in the 80's that he never was able to put them on, and now he does so that might be a hitch.
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From: Millington Illinois
St. Jude Donor '08-'09
Originally Posted by Demonic Possession
I know about the compliment things, only problem is that my dad bought some 2.02 heads back in the 80's that he never was able to put them on, and now he does so that might be a hitch.
Some good street combos on this site. I keep posting this when I see people asking for build advice but the mods won't make it a sticky. Check it out at www.ryanscarpage.50megs.com/combos1.html
Last edited by 63mako; Oct 10, 2006 at 11:21 PM.
Thread Starter
Pro
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From: Chicago IL
Cool, thanks for the site, it really SHOULD be a sticky. I just asked my dad and this is what he said about the heads: 2,02 angle plug heads,milled,polished(maybe), 3 angle valve job, and they're cleaned. He bought them in the 80's for the vette, but never had a chance ot put them on. They're still wrapped in plastic.
Le Mans Master
Joined: Sep 2001
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From: Unreconstructed, South Carolina
Originally Posted by Demonic Possession
heads: 2,02 angle plug heads,milled,polished(maybe), 3 angle valve job, and they're cleaned.
Race Director
Joined: Jun 2000
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From: FL
Those heads are very likely old school 2.02 heads. You are better off selling them to someone doing a restoration and buying a new set. The lastest head designs have some incredible flow numbers and you need to be able to flow to make power.
Race Director
Joined: May 2005
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From: Millington Illinois
St. Jude Donor '08-'09
Originally Posted by Demonic Possession
Cool, thanks for the site, it really SHOULD be a sticky. I just asked my dad and this is what he said about the heads: 2,02 angle plug heads,milled,polished(maybe), 3 angle valve job, and they're cleaned. He bought them in the 80's for the vette, but never had a chance ot put them on. They're still wrapped in plastic.
with Steve, Are they stock GM heads? If so post the casting #s and Date code from both heads. The date code should be right under the casting mumber. It is a letter number number number let's see what you got. With the #s will be able to tell the cc and figure flow #s. Some of these older heads are worth more to a restorer than a new set of higher flow aluminum heads would cost.
Le Mans Master
Joined: Jan 2006
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From: Butler Pa
Originally Posted by 63mako
with Steve, Are they stock GM heads? If so post the casting #s and Date code from both heads. The date code should be right under the casting mumber. It is a letter number number number let's see what you got. With the #s will be able to tell the cc and figure flow #s. Some of these older heads are worth more to a restorer than a new set of higher flow aluminum heads would cost.I beleive that the set I have are 68 cc.
Le Mans Master
Joined: Oct 2001
Posts: 5,943
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From: Wildwood IL
Originally Posted by Demonic Possession
Hmmm...never thought of that. How much would the 817 or 509 cost? I went to a few speed shops today and after reading everyone's comment's, it looks like I'm going with the 400( or maybe what edzred suggest need to research it more), thanks!
Too many guys go shopping for parts armed with money...instead of knowledge, and end up wasting it. Don't make that mistake....
Good Luck
Eddie
P.S. On the other hand...Dart makes a great brand new 4.125 bore SB called "Little M". Ready to hone and assemble. Cheapest I've seen is $1800 from Compitition Products in Wisconson.
Last edited by Edzred72; Oct 11, 2006 at 08:58 AM.
C6 the C5 of tomorrow
Joined: Nov 2000
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From: Twin Cities Minnesota
68cc might be a bit small for a 400 without big dishes in the pistons.
My 434 with 76cc heads needed 9cc dishes to keep the compression down to 10.5:1
Get a good aluminum head
My 434 with 76cc heads needed 9cc dishes to keep the compression down to 10.5:1
Get a good aluminum head