anyone here ever swap the stock bolts out with no additional changes? im thinking of trying to get rid of some front end weight by swapping my K member and A arms out and that would allow me to drop the oil pan. i know upgrading to arp 2000 rod bolts is worth it but havent heard many people do it.
swapping rod bolts
- Thread starter stal94gt
- Start date
He is right, leave them alone. I do not think I remember hearing of anyone having problems with the stock bolts on an original motor. Plus if the new bolts have higher holding pressure at the same torque rating it could close up the tolerance a little on an already tight motor.
When you install new rod bolts you need to have the big end of the rod resized by a machine shop.
Are you sure about this?
OP, dont change the bolts. A supercharged engine actually puts LESS stress on the rod bolts because the added pressure in the cylinder pushes the piston/rod assembly down, rather than a NA engine doing some PULLING of the rod back down.
When you pull a stock rod its going to have areas that are out of round on the big end from trying to stop the piston from flying out the head.
I don't agree with the supercharger puts less stress on the bolts. If you are pushing down harder there is a rod and piston combo going up on another side with more force now and it needs to be stopped when it reaches TDC so it doesn't fly out the top of the bore. All that force is placed on the rod bolts and big end cap to hold that shit together.
If running a lot of boost on stock motor id be more worried about head studs than the rod bolts.
I bought a set of ARP2000 bolts and never used them. I would still like to install them but dropping the K on just jack stands doesn't sound like a whole lot of fun.
If you are not bumping the rev limiter up they probably are not going to be needed for most of us. However revving to 7 regularly or over would make them a viable mod.
The big end resizing I believe is not going to be needed for cap screw style rod bolt like ours, but may be required for rods with bolts like these:
Without a doubt if the bolt size is increased.
If you are not bumping the rev limiter up they probably are not going to be needed for most of us. However revving to 7 regularly or over would make them a viable mod.
The big end resizing I believe is not going to be needed for cap screw style rod bolt like ours, but may be required for rods with bolts like these:
Without a doubt if the bolt size is increased.
Jimmy is correct...the 03 04cobra rods take just a bolt. The ones in the pic remind my of rods from my pushroded 351w. Thats what the stock bolts looked like with a bolt and nut at the bottom.people call them foot ball heads cause the top of the bolt is shaped like a football.
Last edited:
I didn't.
I would have had them checked for roundness as I know my stock rods on the big end you can feel where its out from the force of the piston being stopped.
Did you at least check them or just rebearing and toss in?
Read #2 here. Those are the replacement bolts for our rods.
I've rebuilt hundreds of motors so yes I checked them. Most people don't know how to use a micrometer and are just weekend warriors so for them I'd recommend having a machine shop mic everything for them.
some forged h-beam rods do need machining to fit the ARP2k bolts, but I'm have never used the the factory manley's, so I can't confirm compatibility on those.
Users who are viewing this thread
