[2506CYL]

Hey everyone,

This is Chris again, I was wondering whats the diffrence between 2 and 4 Bolt blocks and does it affect the performance? And whats the best way to have a 2 bolt block running mild perfomance.Thanks

chris <img src="confused.gif" border="0">

[willys36@aol.com]

Many, many reliable high horsepower 2-bolt SBCs have been made over the years. You can extract a lot of power from them with little concern for reliability. That being said, the 4-bolt main bolcks (came from the factory as heavy duty truck engines) are desireable due to a little more robust bottom end. If you have a 2-bolt block you want to do a mild hop-up to, go ahead with out any worrys.

[tm454]

I agree with willies36 about the 2 bolt main blocks. They can be beefed up with a splayed 4bolt brgn block and the block drilled for the 2 extra bolts if you want to make lots of HP with one of them. Don't know what kind of HP your talking about so by mild performance you might upgrade the cam and port and polish the heads. Add headers and a highrise intake. Is this a roller engine or and older block? You can run a solid roller cam and roller rockers. What size car are you planning to run this in and how deep are your pockets? $$$$ makes Hp and torque. I love this Hobby!


Todd

[larson_lars64]

i would agree that 2 bolt main blocks are good for power, but if you start pushing too much power i would have it made into a 4 bolt main. It just depends on how much power you are putting into the engine. I always think it's better to be safe instead of taking the risk of wrecking the engine. A machine shop can put in splay bolts to make it a 4 bolt main.

[Centerline]

I agree with Willys36. The world is full of powerfull 2 bolt main small block Chevys. If you're going racing a 4 bolt main block would be what you really need but mild or even more than mild small blocks run very reliably with 2 bolt mains all the time.

Centerline
<a href="http://hrrp://www.hotrodsandhemis.com" target="_blank">hrrp://www.hotrodsandhemis.com</a>

[Biggarmike]

Anything under 6500 or 7000 RPM 2 bolt mains are fine. You can make gobs of horsepower below 6k. Basic answer: if its for the track where you will be winding it to its limits on a consistant basis, a 4 bolt would make sense. A studly street machine with the occasional visit to the tree will be fine with a 2 bolt. (balance every engine, no matter what! it will save you money)

[deuce_454]

your money is much much! better spent ballancing your rotating assembly than spending money on 4 bolt main caps, and allign boring and subsequent honeing.

A dynamically ballanced rotating assembly in a squaredecked 2 bolt block with arp studs will survive 550 hp and 7000 rpm for years of driveing.

[ January 13, 2003: Message edited by: deuce_454 ]</p>

[72 chevy]

previous discussion

[2506CYL]

Thanks guys, you've given me alot of insight about the 2 bolt blocks.I found a bone Stock 327 chevy small block that is a 2 bolt. I may consider buying this instead of that 350. The 327 is only $600.00 what you guys think?Its bone stock with 1.94 heads. I will try to get more infomation on it later on tonight. Thanks guys for all your help. Thanks

chris

<img src="confused.gif" border="0">

[2506CYL]

<img src="graemlins/spank.gif" border="0" alt="[spank]" /> for got to tell you guys that I only plan on giving it about 450-475 HorsePower at the Fly wheel. I intend on dropping it in a 68-72 Nova. Its a street car no like serious track only stuff lol.If you guys got a combo for a 450-475 HP at the flywheel for a 327 2 bolt that would be appreciated. I dont intend to spend over 2,000 on the engine. Thanks

much appreciation

chris

[bo 1972]

Can anyone tell me where to get photos,info,websites on 1933 chevy 1/2 ton chevy trucks.Also I am looking for a grille for a 1933 chevy1/2 ton..
Thanks Bo

[Biggarmike]

450 HP out of a 327 for $2000 will be tough. You shouldn't have any trouble hitting 350-375. What year 327? if it's a pre-68 engine, you may have a steel crank. Check the casting numbers on the crank, heads and block. (mortec.com) With the right heads, CR, cam, and manifold you will be in business.