tazmaniac

what does this do to the compression and the power output,or is it better in the long run to use a 351 crank non standard rod's and forged piston's.

xbgs351

351c & 302C blocks are the same.

Power and torque goes up as the capacity is 16% greater.

302C heads have a smaller combustion chamber, which will give you too much compression unless you open up the combustion chamber.

tazmaniac

it's been suggested that i use a shorter piston any idea's on what's available?

xbgs351

That's only if you retain the 302 rods. ACL, Hypatec and KB make pistons to suit.

pinkbits

351 crank , 302 rods and acl pistons to suit with open chamber heads give about 10.5:1 compression which is a bit too much for a daily driver

get a bit machined out of piston dome to get 9.5 compression , with a stage 3 cam , edelbrock performer manifold , extractors and 3 inch sytem with 2500 stall auto youll get about 230hp at wheels ( this is about 350 hp or 260kw at engine)which will sound great and go too

brenx

Theres no reason 10.5:1 compression can't be run on pump fuel. I used to run 10.5:1 on pump fuel. I used to run 98ron and 95ron without detonation. All with cast iron 2V's. I know run 11.2:1 on 98/95 and 91 due to my alloy heads.

Doming the pistons is the worst thing you can possibly do.

Brenden

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XB Fairmont (street car) 11.07@123.02mph.

xdclevo

Is that with lumpy top pistons?

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10.70 @ 125.00 on the black fun top
408 Cube Cleveland.

russxr67

Pinkbits,how does one get 10.5 with open heads.With a flat top piston my calcs struggle to make 9 to1. As suggested by xdclevo the only way to make that comp is with dome pistons.

pinkbits

10.5 is with open chamber and 6inch (302 )rods and acl pistons ( they make a piston to suit 351 with 6 inch rods-part 8mkry9356)
theres nothing wrong with modifying a piston , if its done accurately and the short block is ballanced properly

xdclevo

The question was are they pop tops or flat top. Just because there is a 6 inch rod on a 351, doen't mean the compression is going to change.
The only piston i see mentioned for the 302 rodded 351, is a flat top, which is low compression with oc heads.

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10.70 @ 125.00 on the black fun top
408 Cube Cleveland.