I saw a completes rotating assembly for sale from Hardcore racing. It is a 427 Stroker kit. Would I use a 350 or a 400 block for that. what would have to be done to the block? IF it isnt to much more work than a 383 I would like to get that kit and build a 427 cubic inch small block. It would be cool to tell some I have a 427 in my 1le. they would be like you have a big block. Then I would be like like NOPE its a SBC motor. That would be sweet!


THanks for any info you guys can give me!

 

A 427 SBC is a 400 block with a 4" stroke crank. The 396 referred to above is a 350 .030" over with a 3.875" stroke.

What you would have to do to the block would depend on what's in the kit. Mostly, you might have to grind around the oil pan rail and the bottom of the cylinders for rod clearance, and you might have to use a small base circle cam. The thing that would make the most difference is what rods they supply.

The biggest I've ever made was a 434... same thing as a 427, except .030" overbore. But that's not the same as saying the biggest possible.

I wouldn't recommend anything of that kind for an inexperienced builder.

 

Ok so what if I showed the kit to a good engine building/machine shop. Would they know what would have to be done to the block? I could just take them the block and the kit and have them assemble a short block for me. What kind of an aftermarket block are we talking about? I have never really looked at them. What kind of advantages do they have? And which kind should I use for a set up like this. How much money are we talking about? The kit I can get the guy wants 1,600 for. He said it is still brand new and he paid 1,900 for it. He never used it or even opened it up. But I looked at the kit in Summit and it has a forged4130 steel crank, clevite bearings, forgend 4340 steel rods, JE/SRP pistons, and speed pro rings. I have about 7,000 dollars to build a motor and I already have a set of Edelbrock RPM heads. would these feed enough air to that number of cubic inches? Also what is the difference between 4130 steel and 4340 steel? Is it strength? If so why wouldnt you want you crank and rods to be the same strength?

 

The World Products Motown blocks look very promising. 4.125" bore, no rail clearancing required, fixed the problems production blocks had for performance/stroking, etc. About $1800 bare.

4130 is a chrome-moly steel alloy, 4340 is a higher carbon, nickel-chrome-moly alloy (the last two numbers represent the carbon content, xx30 has .3% nominal carbon content, xx40 .4%, etc.). 4340 also has a slightly higher manganese content. There's no particular reason why they should be the same material. The crank needs to sustain torsion, compression and tension forces, while the rods are primarily under compression and tension. Their overall design is really completely different, so material choice doesn't have to follow one with the other.

 

I really like Mark Stielow's Donovan 427 he uses for road racing in his 68 Camaro. Wow, except that's a lot of money.

 

friend of mine has a 432 sbc in his 72 rs/z28 and its makin about 530 hp with out juice. just my .02

 

I've heard as high as 454, but that puts a big crunch on reliability. Really thin walls speciality parts all around. Lots of money. I wouldn't ever recomend going farther than .060 over on a street engine.

 

Those world products look dammn good but there are some nice Bowtie blocks out there in GM land!

 

The 454 SBC can't be done with a factory production block. You need an aftermarket block with thicker cylinder walls to be able to bore it out more.

427 and 434 can both be done with production blocks but again you're really pushing it. Is it worth investing that much money on the chance of the factory block failing.

Another think to consider when making a large SBC. You need to invest in very good heads. Even the smallest BBC heads flow more than most good SBC heads. You need to get the air into those cylinders to be able to use all those cubic inches.

 

motown makes a 443 crate motor

 

Not only does that expose stength problems but also over bore on a 400 block usually causes excessive heat between cylinders
3,5 and 4,6.
Not the easiest of beast for a street car.

 

be careful about dealing with the vendor you mentioned. their bare parts (blocks, heads) are good quality, but their machining, assembly and after sale customer service leave something to be desired. I live near their facility and most of the locals know to steer clear of their machine shop work.