400 small block
Thread Starter
Intermediate
Joined: Apr 2002
Posts: 49
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From: Sault Ste Marie Mi
400 small block
I'm starting a build on a 400 small block and would like some input on cams, heads, pistons, cranks or whatever anyone has advice on or experience with. I would like a setup for street in the 400-450 hp range with matching torque. Also would like carb size info. Thanks, :p:
Pro
Joined: Jun 2001
Posts: 683
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From: Calgary
Re: 400 small block (Mighty Mouse)
1st of all get your block sonic checked before you do any machining. Some 400 blocks have really thin bores. Then buy David Vizard's book on how to hot rod small block Chevy's, there is a lot of good basic info in the book.
How much money do you have to spend? 400 and larger need the best of heads to make top power. I have AFR 210's, which flow pretty good. Also 400's make a lot of compression with a flat top piston, so you will need 76cc heads if you go flat top piston (AFR 210's are 76 cc). 750 should be all you need for carburation. I'm running a crane roller cam with 222 in and 230 ex duration at .05 lift. I could have made up to 50 hp more with a more aggressive cam, but chose to have a really streetable set up (I have a mild lope at idle). I ditched the stock crank and replaced it with a Scat crank designed and balanced for 6 inch rods. I am running 4340 6 inch eagle h beam rods, and srp forged flat top pistons. Also Team G 7530 single plane intake. Results are in my sig.
How much money do you have to spend? 400 and larger need the best of heads to make top power. I have AFR 210's, which flow pretty good. Also 400's make a lot of compression with a flat top piston, so you will need 76cc heads if you go flat top piston (AFR 210's are 76 cc). 750 should be all you need for carburation. I'm running a crane roller cam with 222 in and 230 ex duration at .05 lift. I could have made up to 50 hp more with a more aggressive cam, but chose to have a really streetable set up (I have a mild lope at idle). I ditched the stock crank and replaced it with a Scat crank designed and balanced for 6 inch rods. I am running 4340 6 inch eagle h beam rods, and srp forged flat top pistons. Also Team G 7530 single plane intake. Results are in my sig.
Melting Slicks
Joined: May 2002
Posts: 2,508
Likes: 0
From: Wisconsin
Re: 400 small block (Mighty Mouse)
JD pistons are the lightest so they make the more power and allows you to get the revs up quick. Problem with 400's is that there is no waterjacket between the cylinders so they run a bit hotter and you can't get that factory chamfer out of the cylinders. You need to go .020 over to get it all machined smooth for maximum power. A good book is The Chevrolet Racing Engine by Bill Jenkins. They go through all the steps of building up a small block. Out of print now I'm sure. My dad loaned it to me to read. It is leftover from his drag racing days :cool:
Racer
Joined: Jan 2002
Posts: 440
Likes: 2
From: Smithfield NC
Re: 400 small block (Schmucker)
I plan on building a small block 427.400 block with 4inch crank.I'm going to have to look for these books.I have to find a 400 small block first.They're harder to find than 327 double hump heads.
Melting Slicks
Joined: Dec 2000
Posts: 2,198
Likes: 2
From: Eastern Connecticut
Re: 400 small block (blackLS1)
I used flattop pistons (10:1 comp), 882 (884?) heads with 2.02/1.60 valves, and the first L82 cam with 1.6 rockers. That motor loved to rev, really woke up at 3000, and would turn to 6000 no problem. I used stock rods with ARP bolts. Had the assembly balanced too. It was fun in a 2500 lb street rod with 4.11 gears and a 4-speed. Tough to launch, but the torque was awsome. Joe
Instructor
Joined: Jan 2002
Posts: 185
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From: Surrey BC
Re: 400 small block (Mighty Mouse)
I put my 400 together this spring and am very happy with it so far, good power and torque, no temp problems. Most info is in my sig. My brother recommended the cam after he tried 4 other ones in his 400 over a 2 week span. It's an Ertle hyd. cam # 115871, cam lift: .339 int, .355 ex, dur @ .50:244 int, 254 ex. The engine desktop dynoed @ 420 hp@ 5500 and 480 f/lb @4500. I would have preferred AFR 210 heads, but they were a bit out of my budget at the time. The motor sounds very grumpy and pulls good right off idle. Hope this helps, but there are a million different comboes to choose from.
Dave :cheers:
PS: I started with a Holley 650 but later put a 750 on, Much better!!!
Dave :cheers:
PS: I started with a Holley 650 but later put a 750 on, Much better!!!
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Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Re: 400 small block (lyndave75)
It's an Ertle hyd. cam # 115871, cam lift: .339 int, .355 ex, dur @ .50:244 int, 254 ex. The engine desktop dynoed @ 420 hp@ 5500 and 480 f/lb @4500.
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Re: 400 small block (74vetteman)
73vetteman
I have that book and it is an excellent reference. I hear conflicting info from some forum members but I like to have as many reference as possible before doing something I know little about. The thing I like most about it is he is making suggestions for building a 'streetable' high performance engine and knows that most street engines live from idle to 5000 or 6000 rpm's not from 4000 to 7000. As as he notes, some of the info is dated so make sure you look for the latest info.
I have that book and it is an excellent reference. I hear conflicting info from some forum members but I like to have as many reference as possible before doing something I know little about. The thing I like most about it is he is making suggestions for building a 'streetable' high performance engine and knows that most street engines live from idle to 5000 or 6000 rpm's not from 4000 to 7000. As as he notes, some of the info is dated so make sure you look for the latest info.
Drifting
Joined: Jun 2001
Posts: 1,809
Likes: 0
Re: 400 small block (Mighty Mouse)
If you haven't checked out his sight it might help http://www.ryanscarpage.50megs.com/ It has a lot of small block combos and at least one 427 sb combo.
Thread Starter
Intermediate
Joined: Apr 2002
Posts: 49
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From: Sault Ste Marie Mi
Re: 400 small block (Mighty Mouse)
Want to thank everyone for their input. I think I am heading in the direction I want to go. Learned allot as usual on this forum. Keep up the great work guys. :cheers:
C6 the C5 of tomorrow
Joined: Nov 2000
Posts: 6,665
Likes: 2
From: Twin Cities Minnesota
Re: 400 small block (Mighty Mouse)
Be very cautious about listining to people who want you to build a drag race motor. unless you plan on building a drag ONLY car there is no need for forged pistons, splayed main caps and all that BS.
Build a good streetable motor, Hyperuteutic pistons, a nice wide lobe seperation, and a good dual plane manifold. Yea, there will be guys around with 1000hp blown / sprayed / intercooled blah blah blah, but so what?
BTW I built a 434 small block and am living with some questionable decisions, IM or Email if you want more info...
Build a good streetable motor, Hyperuteutic pistons, a nice wide lobe seperation, and a good dual plane manifold. Yea, there will be guys around with 1000hp blown / sprayed / intercooled blah blah blah, but so what?
BTW I built a 434 small block and am living with some questionable decisions, IM or Email if you want more info...
