400,406 cid - stem holes ?
Thread Starter
Pro
Joined: Apr 2000
Posts: 589
Likes: 3
From: Acapulco Guerrero
400,406 cid - stem holes ?
Hi,
Please help me with this:
I need an engine for a new project, in this moment I don`t have anything, I want a 400 cid of displacement or 420 from a small block.
I will buy a block from a yunkyard
Can I convert a 350 to 400 ? or will be a better idea to buy a 400
1.- I know that the crank (stroke)will be not a difficult problem (383) but what about the 4.155 inch bore in a 350 ?
2.- If I will buy a 400, I already have the stroke and the bore but what about the siamesed bores (stem holes)in this engine ?
Because I want to install afr 190.
3.- how difficult will be to drill this stem holes on the new heads ?
4.- If I stroke a 350 to 406 I supose that I will not need the stem holes ?
Let me know
Thanks and regards
Please help me with this:
I need an engine for a new project, in this moment I don`t have anything, I want a 400 cid of displacement or 420 from a small block.
I will buy a block from a yunkyard
Can I convert a 350 to 400 ? or will be a better idea to buy a 400
1.- I know that the crank (stroke)will be not a difficult problem (383) but what about the 4.155 inch bore in a 350 ?
2.- If I will buy a 400, I already have the stroke and the bore but what about the siamesed bores (stem holes)in this engine ?
Because I want to install afr 190.
3.- how difficult will be to drill this stem holes on the new heads ?
4.- If I stroke a 350 to 406 I supose that I will not need the stem holes ?
Let me know
Thanks and regards
Melting Slicks
Joined: Dec 2001
Posts: 2,025
Likes: 1
From: Billings MT
Re: 400,406 cid - stem holes ? (Eduardo L98 1991)
You don't want to bore a 350 much over .060, so theoretically, no, you cannot get the 400 your looking for from your 350. You can (i think) however run a longer stroke to make a SB396. [3.850 Stroke, 4.030 bore].
I'm not sure if you can run 4 inches of stroke in a 350, but with the small bore I don't think it would be worth it.
I am currently building a small block 406 from a 400 block, and I'm using the AFR 195's....In fact they are sitting beside me at the moment.
I had AFR machine the steamholes for me, it was only $55 and they came out good. If you want a picture, I'll upload one shortly.
:cheers:
Well, I figured you'd like the picture, so here you go :)
[Modified by VETDRMS, 8:56 PM 5/18/2003]
I'm not sure if you can run 4 inches of stroke in a 350, but with the small bore I don't think it would be worth it.
I am currently building a small block 406 from a 400 block, and I'm using the AFR 195's....In fact they are sitting beside me at the moment.
I had AFR machine the steamholes for me, it was only $55 and they came out good. If you want a picture, I'll upload one shortly.
:cheers:
Well, I figured you'd like the picture, so here you go :)
[Modified by VETDRMS, 8:56 PM 5/18/2003]
Drifting
Joined: Jul 2001
Posts: 1,897
Likes: 0
From: La Fontaine Indiana
Re: 400,406 cid - stem holes ? (Eduardo L98 1991)
Thanks for your answer
Then I will go for a 400 block, and I will ask for the stem holes like you to afr
Thanks and regards
Then I will go for a 400 block, and I will ask for the stem holes like you to afr
Thanks and regards
Le Mans Master
Joined: Jul 2001
Posts: 8,183
Likes: 3
From: Santa Maria, CA
Re: 400,406 cid - stem holes ? (Eduardo L98 1991)
I think there are car 400 blocks and truck 400 blocks with a taller deck height. Check that out before buying it. I think the casting # will tell that.
I am doing 391 CID 3.835 stroke in a 4.030 bore. (350 block) Maybe I can get 1 more rebuild out of those cylinders when the time comes.
There is a nice article in february 2003 Chevy High Performance magazine about drilling steam holes (don't forget the gaskets). I can fax it to you if want.
AFR:
yes tell them to add sensor locations. I didn't and I don't have them. I am using 210cc. Part #1053 (L98 plug angle for corvette). They will take about 2 months if not more to make the heads. Maybe next year AFR moves to a bigger facility to make faster head orders. But they are beautiful heads.
very nice CNC ing. The Fel-pro 1205 fits very nice on the port.
[Modified by 89 Paul in Cal, 4:35 AM 5/19/2003]
I am doing 391 CID 3.835 stroke in a 4.030 bore. (350 block) Maybe I can get 1 more rebuild out of those cylinders when the time comes.
There is a nice article in february 2003 Chevy High Performance magazine about drilling steam holes (don't forget the gaskets). I can fax it to you if want.
AFR:
yes tell them to add sensor locations. I didn't and I don't have them. I am using 210cc. Part #1053 (L98 plug angle for corvette). They will take about 2 months if not more to make the heads. Maybe next year AFR moves to a bigger facility to make faster head orders. But they are beautiful heads.
very nice CNC ing. The Fel-pro 1205 fits very nice on the port.[Modified by 89 Paul in Cal, 4:35 AM 5/19/2003]
Pro
Joined: Dec 2001
Posts: 708
Likes: 0
From: Renton Wa
Re: 400,406 cid - stem holes ? (89 Paul in Cal)
I am curious about this Steam Hole drilling? are there reciever holes on the block side? I have a 400 dart block "building a 406 as well" and I don't have any steam holes on the deck surface. So I have just put that issue to the side. Not that it is a big issue, won't take much to drill them out.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: 400,406 cid - stem holes ? (WashingtonRacer)
WashingtonRacer,
I inquired about have those holes drilled in my Bowtie Block. The machine shop said the deck was too thick. Look down an adjacient water passage to see how deep you would have to drill. Better yet, ask your machine shop. All production, 400 sbc's, have the steam holes.
There are no production Chevy "tall deck" small blocks. The responder above, I forgot to note his forum name, is thinking of medium duty truck big blocks.
RACE ON!!!
1984 Crossfire
Member NHRA
I inquired about have those holes drilled in my Bowtie Block. The machine shop said the deck was too thick. Look down an adjacient water passage to see how deep you would have to drill. Better yet, ask your machine shop. All production, 400 sbc's, have the steam holes.
There are no production Chevy "tall deck" small blocks. The responder above, I forgot to note his forum name, is thinking of medium duty truck big blocks.
RACE ON!!!
1984 Crossfire
Member NHRA
Le Mans Master
Joined: Jul 2001
Posts: 8,183
Likes: 3
From: Santa Maria, CA
Re: 400,406 cid - stem holes ? (CFI-EFI)
There are no production Chevy "tall deck" small blocks. The responder above, I forgot to note his forum name, is thinking of medium duty truck big blocks.
this is from Ed's other post:
in my country never sold 400 engines then I need to search one in the junkyard in 70's usa made trucks.
why I mentioned it. Ed is in Mexico and I am Mexican also. I haven't been down south in a few years, but am familiar with how things are down there :D
Just was trying to give a heads up on possible block differences. :cheers:
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Pro
Joined: Dec 2001
Posts: 708
Likes: 0
From: Renton Wa
Re: 400,406 cid - stem holes ? (CFI-EFI)
I would hope don't need to have any drilled, My deck surface is very thick, I don't have any actual numbers on hand, but comparted to a stock block, this deck is much more thick.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: 400,406 cid - stem holes ? (89 Paul in Cal)
Of course I have no idea what Chevy/GMC used or sold in Mexico, but either way, there is no risk of getting "stuck" with an unusable TALL deck small block.
Another source of 400 blocks, are passenger cars. Full sized and some Chevelles, I believe. Again, I have no idea what was made in or for use in Mexico, but cars are an additional venue for the 400 cid sbc.
Just trying to help. Good luck, and...
RACE ON
1984 Crossfire
Member NHRA
that is
why I mentioned it. Ed is in Mexico and I am Mexican also. I haven't been down south in a few years, but am familiar with how things are down there :D
Just was trying to give a heads up on possible block differences. :cheers:
why I mentioned it. Ed is in Mexico and I am Mexican also. I haven't been down south in a few years, but am familiar with how things are down there :D
Just was trying to give a heads up on possible block differences. :cheers:
Just trying to help. Good luck, and...
RACE ON
1984 Crossfire
Member NHRA
