If you mean adding splayed 4 bolt caps to a 2 bolt block it would much stronger than a stock 4 bolt.

 

If you mean adding splayed 4 bolt caps to a 2 bolt block it would much stronger than a stock 4 bolt.

hey buddy

saw one of your posts on hotrodders. what needs to be done to convert a 2-bolt block to a 4-bolt. is it simply a matter of purchasing 4-bolt caps and having the block drilled and tapped for the new caps. what are splayed caps anyway.

Lee

 

Its not quite as simple as drilling and tapping. You will also have to have the block and caps align honed. Splayed refers to the fact that the bolts will not be "square" to the block. I have also heard it said that once you remove the material from the webs by drilling for the other two bolts that the structural integrity of the block may be compromised so it may or may not be stronger than a stock 2 bolt.

 

Its not quite as simple as drilling and tapping. You will also have to have the block and caps align honed. Splayed refers to the fact that the bolts will not be "square" to the block. I have also heard it said that once you remove the material from the webs by drilling for the other two bolts that the structural integrity of the block may be compromised so it may or may not be stronger than a stock 2 bolt.

Most every race shop says the converted stock block to splayed 4 bolt is stronger than the factory 2 or 4 bolt. They should know, they blow them up all the time.... LOL

www.readershotrods.com add your ride

 

I have also heard it said that once you remove the material from the webs by drilling for the other two bolts that the structural integrity of the block may be compromised so it may or may not be stronger than a stock 2 bolt.

Sounds like your thinking of the production 4 bolt 400 blocks which are weaker than the 2 bolts because of the lack of meat in the main areas. Probably due to the larger main bores but dont quote me on that.

 

Had my dog splayed...He's got main bolts but no nuts...

 

how far would you veteran engine builders/racers push a all motor 350 2 bolt block or a 400 4 bolt block as far as HP ? would you be afraid to full time race a 350 2 bolt block ? you know some where in the 450HP all motor range ? you know something in the mid 12s or high 12s.


or full time race a 450HP to 500 HP all motor 400 4 bolt block ?







Mustangsaly

 

not all 4 bolt blocks are splayed caps.a 4 bolt splayed block is stronger then a standard 4 bolt block.so why would you compair any of this?fact is stength would be that a 2 bolt block is weaker with or without splayed caps it's the cap that is stronger,also depending on casting #'s as to the tin and nickel percentage.heavier castings are going to be thicker in the main webing and different main cap casting #'s also make a difference.
my question is why would you want to take a 2 bolt block and spend the money to make it a 4 bolt splayed cap?cuz if you your going to make that kind of power you should go with an after market block with splayed caps to begin with,or you will break the block and be buying an after market block in the long run or just throwing good money after bad.
just my thoughts,i have done these modifications to 2 bolt blocks before because the customer wanted and insisted it was better.i have built a 2 bolt block up to between 400-500hp with no breakage.if you break'em then your not just racing your beatin on it and there is a difference.

 

Im FAR from an engine builder but I personally ran a studded 2 bolt main flat top 350 for 4 years in a 3400-ish lb camaro. 6.90@102 1/8 mile. 7000 rpm shifts with 125 shot of nitrous. After 2 years I freshened the engine and the caps did show signs of walking.I ran it 2 more years and ended up spinning a bearing.

 

so I assuming a 2 bolt 350 block is plenty strong for 450ish + HP on strip time ? what do you think a 350 4 bolt main block is good for ? (assuming both are high nickel/tin blocks)

any opinions on what a 1 piece rear main 350 2 bolt block (1986 up) is good for HP wise ? I'm asking cause most of these were roller blocks, and I have one.


Nothing I'm asking about would there be need for a aftermarket block. I'm thinking a 450HP 355 and a 525HP 383







Mustangsaly