385,400,427 ???
Thread Starter
Racer
Joined: Oct 2007
Posts: 284
Likes: 6
From: Palm PA
385,400,427 ???
It's snowing so I am thinking about a better engine for my car. I have a 350 block to be bored and stroked for a 385. I can also get a 400 block from the machine shop. Both of these would work fine. Is it possible to stroke the 400 block with a 4" throw on the crank to make it a 427" small block and have the crank clear the cam with 6" connecting rods? I will do the assembly myself. This would be a "cruiser motor" with the occasional open road blast now and then. Any comments or info on the three engines will be helpful.
Thanks,Dave
Thanks,Dave
Drifting
Joined: Jul 2002
Posts: 1,944
Likes: 20
From: The only Corvettes in Highett Victoria
427???
vetteman,
You won't get 427 cubic inches with a 4.00" stroke and the standard 4.00" bore. That will only give you 402 ci. You will need to bore out to about 4.125" to get to seven litres. You can obtain 7 litres with a 4 inch bore, but would have to stroke it to 4.25" and then the rods would be getting pretty friendly with the camshaft.
Not saying it can't be done, but it would take $$$$$$$$$$$$$$$$$. If only Chevrolet had put the camshaft passage in the block about half an inch higher up and the side rails about half an inch further apart. I guess we'd never have had the big block if they'd done that.
Regards from Down Under
aussiejohn
7 months to go
You won't get 427 cubic inches with a 4.00" stroke and the standard 4.00" bore. That will only give you 402 ci. You will need to bore out to about 4.125" to get to seven litres. You can obtain 7 litres with a 4 inch bore, but would have to stroke it to 4.25" and then the rods would be getting pretty friendly with the camshaft.
Not saying it can't be done, but it would take $$$$$$$$$$$$$$$$$. If only Chevrolet had put the camshaft passage in the block about half an inch higher up and the side rails about half an inch further apart. I guess we'd never have had the big block if they'd done that.
Regards from Down Under
aussiejohn
7 months to go
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
people do make 4 inch stroker 350's and 400 blocks. I prefer the 3.875 cranks.
I do not like or build stock 400 blocks.
www.flatlanderracing.com is where I buy the complete rotating kits
I do not like or build stock 400 blocks.
www.flatlanderracing.com is where I buy the complete rotating kits
Thread Starter
Racer
Joined: Oct 2007
Posts: 284
Likes: 6
From: Palm PA
vetteman,
You won't get 427 cubic inches with a 4.00" stroke and the standard 4.00" bore. That will only give you 402 ci. You will need to bore out to about 4.125" to get to seven litres. You can obtain 7 litres with a 4 inch bore, but would have to stroke it to 4.25" and then the rods would be getting pretty friendly with the camshaft.
Not saying it can't be done, but it would take $$$$$$$$$$$$$$$$$. If only Chevrolet had put the camshaft passage in the block about half an inch higher up and the side rails about half an inch further apart. I guess we'd never have had the big block if they'd done that.
Regards from Down Under
aussiejohn
7 months to go
You won't get 427 cubic inches with a 4.00" stroke and the standard 4.00" bore. That will only give you 402 ci. You will need to bore out to about 4.125" to get to seven litres. You can obtain 7 litres with a 4 inch bore, but would have to stroke it to 4.25" and then the rods would be getting pretty friendly with the camshaft.
Not saying it can't be done, but it would take $$$$$$$$$$$$$$$$$. If only Chevrolet had put the camshaft passage in the block about half an inch higher up and the side rails about half an inch further apart. I guess we'd never have had the big block if they'd done that.
Regards from Down Under
aussiejohn
7 months to go
The 400 blocks have a 4.125" bore from Chevrolet as the standard size. Unfortunately they also have a cracking problem on the decks where the "steam holes" are. Hope it's warm where you are. Cold weather sucks.
68 Vetteman
Thread Starter
Racer
Joined: Oct 2007
Posts: 284
Likes: 6
From: Palm PA
people do make 4 inch stroker 350's and 400 blocks. I prefer the 3.875 cranks.
I do not like or build stock 400 blocks.
www.flatlanderracing.com is where I buy the complete rotating kits
I do not like or build stock 400 blocks.
www.flatlanderracing.com is where I buy the complete rotating kits
They have some interesting stroker crate engines.The shop that has the 400 block told me they have a problem with cracks on the decks near the head bolts.
68 Vetteman
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Best bang for your buck is a 406ci,400ci block and 3.75" stroke crank, no clearancing necessary and big cubes and big power. Check into it, get the block from the machine shop doing the work, then it's their responsibility 
I built a 427ci but used aftermarket Motown block and 4 inch crank, very happy with the results
I built a 427ci but used aftermarket Motown block and 4 inch crank, very happy with the results
Thread Starter
Racer
Joined: Oct 2007
Posts: 284
Likes: 6
From: Palm PA
Best bang for your buck is a 406ci,400ci block and 3.75" stroke crank, no clearancing necessary and big cubes and big power. Check into it, get the block from the machine shop doing the work, then it's their responsibility
I built a 427ci but used aftermarket Motown block and 4 inch crank, very happy with the results
I built a 427ci but used aftermarket Motown block and 4 inch crank, very happy with the results
The stroked 400 block sounds tempting. Great looking 427. How close does the crank come to the cam with a 4" stroke? Did you have to use a small lobe cam on your 427?
Thanks, 68 Vetteman
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