400 chevy block in C4?
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Joined: Nov 2006
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From: McKinleyville CA
400 chevy block in C4?
Considering building an engine based on the Chevy 400 to replace my factory L98. Any problem areas with this conversion? Clearance, exhaust, mounting, or intake issues or is it just about a direct replacement? Yes, I have used the search function!
Drifting
Joined: Apr 2007
Posts: 1,339
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From: port charlotte fl
Go and buy John Lingenfelters book"modifying small block chevys" It's $15.00 and a wealth of info.That engine is discussed and should put out around 525HP and 543 ft/lbs.Torque monster.And it fits.
Race Director
Joined: Sep 2000
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From: The Top of Utah
Originally Posted by 94ZR1
Just use a 350 block with a 400 crank for a 383
The 400 is just another small block, with a few of it's own peculiarities. All of the external dimensions are common to all SBCs. The heads, intakes, exhausts, etc. all interchange. The 400, being a pre 1986 engine, has a two piece rear main seal and the accompanying crank shaft. The 400 uses it's own unique flywheel/flex plate and damper due to the external balance. A 400 (406) in place of an L98 is a piece of cake. Although not particularly advisable for a high output engine, the stock TPI will bolt up and work.
RACE ON!!!
Melting Slicks
Joined: May 2001
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From: Winchester VA
Cruise-In V Veteran
Good luck getting a 400 crank to sit down into the 350 block main bearing saddles.
The 400 is just another small block, with a few of it's own peculiarities. All of the external dimensions are common to all SBCs. The heads, intakes, exhausts, etc. all interchange. The 400, being a pre 1986 engine, has a two piece rear main seal and the accompanying crank shaft. The 400 uses it's own unique flywheel/flex plate and damper due to the external balance. A 400 (406) in place of an L98 is a piece of cake. Although not particularly advisable for a high output engine, the stock TPI will bolt up and work.
RACE ON!!!
The 400 is just another small block, with a few of it's own peculiarities. All of the external dimensions are common to all SBCs. The heads, intakes, exhausts, etc. all interchange. The 400, being a pre 1986 engine, has a two piece rear main seal and the accompanying crank shaft. The 400 uses it's own unique flywheel/flex plate and damper due to the external balance. A 400 (406) in place of an L98 is a piece of cake. Although not particularly advisable for a high output engine, the stock TPI will bolt up and work.
RACE ON!!!
And with an internally balanced rotating assembly...your 350 balancer and flywheel/flexplate will work.
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Joined: Sep 2000
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From: The Top of Utah
True. But at great expense. The stock 400, externally balanced damper is 8" in diameter. It won't fit unless the cross member is modified. The other alternative (other than internally balancing the engine) is to pick up a specialty damper that is smaller (stock is 6 3/4") with the 400 imbalance. You, also, could probably have the L98 damper re-weighted to meet the 400 spec. The 400 was never available with a 153 tooth flywheel or flex plate. In the rear, if it is an auto, it is easiest to retain the 168 tooth, 400, flex plate and switch to (or the nose piece for) a 400 starter. If it is a manual, the 400, 168 tooth, flywheel won't fit inside of the C4 bell housing. A 153 tooth (for a two piece seal), flywheel will have to be balanced to 400 specs.
These are all just details that will have to be dealt with along the way. The short answer is...It's a bolt in.
RACE ON!!!
PS. And you won't even need a reduced base circle camshaft.
These are all just details that will have to be dealt with along the way. The short answer is...It's a bolt in.
RACE ON!!!
PS. And you won't even need a reduced base circle camshaft.
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Pro
Joined: Jul 2006
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From: chiefland fl
hey bro, im doing this mod right now as we speak, the guys are right about the harmonic balancer. its an 8" and you have to pound out a small area on that cross member, mine is still on the stand though, so i havent got to that point yet. there is some good info about building the engine here http://www.chevyhiperformance.com/te...ild/index.html
i got rid of the crossfire setup and went 4 barrel carb, stayed pretty close to the chevy hp mag build with a few changes, i am putting up pics on my website and info as i go along at http://www.billybonesmusic.com/ under the link Bill's Vette, any info you need ill be around to help ya, but the 400 is one TORQUEY MOTOR!
i bought the Scat balanced rotating assy off my brother in law who bought it from Summit, bored 30 over it's a 406cid. so that had the pro performance dampner, balanced flexplate, and the rest to get you going, you have to modify the head gaskets as well or drill steam holes in your heads (if you don't use the 400 origional heads) because the 400 requires additional cooling if you are gonna run it as a daily driver on the street, other than that, and a few other tricks its a done deal. 383's are cool but i wanted cubic inches along with the stroke! check out the website though, lots of good info!
i got rid of the crossfire setup and went 4 barrel carb, stayed pretty close to the chevy hp mag build with a few changes, i am putting up pics on my website and info as i go along at http://www.billybonesmusic.com/ under the link Bill's Vette, any info you need ill be around to help ya, but the 400 is one TORQUEY MOTOR!
i bought the Scat balanced rotating assy off my brother in law who bought it from Summit, bored 30 over it's a 406cid. so that had the pro performance dampner, balanced flexplate, and the rest to get you going, you have to modify the head gaskets as well or drill steam holes in your heads (if you don't use the 400 origional heads) because the 400 requires additional cooling if you are gonna run it as a daily driver on the street, other than that, and a few other tricks its a done deal. 383's are cool but i wanted cubic inches along with the stroke! check out the website though, lots of good info!
Pro
Joined: Jul 2006
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From: chiefland fl
with my kit, it had the Scat I beam forged rods with capscrews, i STILL had to have Lunati custom grind me a Voodoo cam because the bracket master II cam i had with 489 lift hit the rods! i was soooooooo pis|$%|! they were supposed to be stroker clearanced rods, clearanced for what i dont know! but there are no troubles with the Eagle rods, or H beams from what i hear, but i had probs, but nothing $250 couldnt clear up LOL.
Pro
Joined: Jul 2006
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From: chiefland fl
I disagree........no substitute for cubic inches! if i had to do it all again, and hit the lotto, i would build the new ls6 is it? the small block GM just put in Reggie Jackson's camaro? its a roller block that can be bored out to over 500cid's and its a SMALL block? schweeeeeeeeet! less weight with all the stuff the BIG blocks got! it sells for like $1900 so its not as expensive as those 400 aluminum blocks.
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Joined: Sep 2000
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From: The Top of Utah
Originally Posted by steven mack
A 383 using an 87 and later 350 roller block would be a better choice.
Originally Posted by billybonesmusic
i STILL had to have Lunati custom grind me a Voodoo cam because the bracket master II cam i had with 489 lift hit the rods! i was soooooooo pis|$%|!
RACE ON!!!
Drifting
Joined: Apr 2007
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From: port charlotte fl
Forgot to mention I was doing some browsing the other day and saw some after market 400 cranks already ground to 350 journal size,2.45"with one piece rear seals for, I think, about $375.Don't remember about the balancing set up.I have the 383Lingenfelter and it has the small external balancer which I assume is an aftermarket addition.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
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From: Kempner Texas
Yep, I'm running a retro-fit roller cam setup in my 415, which has a 400 block. Bored .030 and ai drilled the steam holes in the heads. Aftermarket damper that is smaller in diameter than the stock 400 damper in order to clear the chassis and steering in a 86 without any mods.
Also, I'm running early 5.7" rods. The difference is in the rod big end diameter, 2.000" Vs 2.100"' I believe those are the numbers.
Jake
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Joined: Sep 2000
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From: The Top of Utah
Yes, the crank rod journals changed from 2.00" to 2.10" in 1968, when Chevy increased the mains from 2.30" to 2.45". Only the 327 was made with both bearing sizes. All 350s and all 400 came with the "large" 2.10" rod journals. The 400 had 2.65" mains.
RACE ON!!!
RACE ON!!!
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Advanced
Joined: Nov 2006
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From: McKinleyville CA
What about the power handling capabilities between the two? Build formula I am working on is around 500HP but may shoot up to 700hp-750hp if I decide to go with forced induction. I know those power levels will be stressfull on either an L98 or a 400... But which one may accept the torture better?
Melting Slicks
Joined: May 2001
Posts: 3,270
Likes: 26
From: Winchester VA
Cruise-In V Veteran
hey bro, im doing this mod right now as we speak, the guys are right about the harmonic balancer. its an 8" and you have to pound out a small area on that cross member, mine is still on the stand though, so i havent got to that point yet. Scat balanced rotating assy off my brother in law who bought it from Summit, bored 30 over it's a 406cid. so that had the pro performance dampner, balanced flexplate, and the rest to get you going, you have to modify the head gaskets as well or drill steam holes in your heads (if you don't use the 400 origional heads) because the 400 requires additional cooling if you are gonna run it as a daily driver on the street, other than that, and a few other tricks its a donedeal. 383's are cool but i wanted cubic inches along with the stroke! check out the website though, lots of good info!
Internally balanced can use 350 (your stock) flywheel/flexplate, dampner (harmonic balancer) = small, starter.
Externally balanced (stock 400 configuration) requires mods mentioned by CFI-EFI (pound crossmemeber, starter snout.....)
My 5 yr old internally balanced 408 ran all 350 parts on the outside, no steam holes in the heads, and never had a balance or overheat problem.
If someone is going to run an aftermarket rotating assy (strongly recommended as you are likely in for overbore and new pistons anyway) it is no more expensive to go with an internally balanced setup and you can reuse your stuff (harm balancer, starter, fly/flex)
Drifting
Joined: Oct 2006
Posts: 1,328
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From: Stafford Connecticut
I know you can put a retro roller cam in a 400 cause I have a destroked 400 block in my vette now and its a roller cam.It is just cheaper and easier to use a factory roller block.and you can get just as much power and torque out of a 383 as a 400 .
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From: McKinleyville CA
What is the purpose in DE-stroking the 400? Revs?