I am building a 460 (possibly a stroker) for my truck. It will be used for mud bogging but I want to put 87 octane in it. What compression ratio and bore size is best for this application?? I found a stroker kit that says 4.300" stroker crank forged dished pistons .030 over for pump gas compression ratios. As far as I know the engine I have has never been apart. Is .030 over too much,just how much is too much and what is the best compression ratio for 87 octane pump gas?

 

.030 over shouldn't be any problem at all. If you look at the 514's they are like .080 over

 

8:1 or 8.5:1 is about all you can run with 87 octane without having to resort to using "band-aids" to keep the engine from detonating (pinging).

 

Don't most of the 514's use a special FRPP block?

 

No. They use a 2-bolt block.

 

Wow, that's alot of faith in a 2 bolt block, but I guess it works.
Jimmy

 

Anybody here used the Keith Black hyperutectic pistons or is it best to used forged ones like the trw's? I'm building a budget motor and really want a good piston with about 10:1 compression. What has to be done to the stock rods to use a floating pin or where can I get a decent set of aftermarket rods? Thanks, Rick

 

I have heard that they work good unless you are using NOS or Forced Induction. The 5.0 Engines had them from 93-up. No problems that I know of.
I don't think that they were Keith Black brand, but I know that he has built many a top fuel Hemi engine.
They should be fine.
Jimmy

 

.030 over is a good "first rebuild" amount. It leaves plenty of meat for future rebuilds amd will usually allow the engine to run a bit cooler than if you really hogged it out. .060 is the usual maximum bore out, but with an expereinced shop and probably checking the block for core shift, you can go larger but will run hotter and the next rebuild would probably require sleeves and not be worth it for a normal engine.

Hyper eutectics are good for normal use but don't like high heat and pressure such as NOS or a supercharger, so I have read.

Good Luck,

Jim Henderson

 

Thanks, I'm basically building the FMS crate motor with a few changes. It's not really that radical of a motor. Any other worthwhile upgrades I can or should do I have a bet with a friend to make 500hp for less than $2 grand not including the
price of the motor since I had it already. I'm also have to use the D3VE heads.

 

I'd think a good 200-250hp on the crate engine comes from the stout cam (not an ideal street cam), high compression, aluminum CJ heads and full headers. Low compression (87-octane) and D3 heads are going to make 500hp tough to obtain.

 

Only thing I'm not using there are the aluminum heads. Compression will be around 10.25 to 1, heads will be heavily ported and I'm using the same cam as the 514 crate motor. I'm also planning on boring it .060 over and will also be using roller rockers. The motor is going into a 3000 lb Mustang with a 3K stall converter and 3.73's. It won't be driven daily so if it isn't totally streetable, doesn't really matter.