rod trouble

[scotiascrapiron]

bought 393w crank,using stock rods and 302 pistons,had crank balanced. installed right bank and everything looked good,tried to install #1 piston and both rods won't fit on journal. what would be my next best course of action? should i try to machine down the sides of the rods? anybody got any thoughts?

 

[mikepotts]

YIKES! sorry for the bad luck... ive thought about building one of those motors for a long time. i probably would have the rods machined.

 

[scotiascrapiron]

YIKES! sorry for the bad luck... ive thought about building one of those motors for a long time. i probably would have the rods machined.

wonder how much I can have ground off and still be safe? I would hate to go to much and have rods flying all over the place.

 

[Combs Customs]

I hate to ask. You do have the bearings installed the correct way right? I know there is a radius on the side of the rod journal, and the bearings should have a matching radius. That would be best case scenario.

 

[scotiascrapiron]

I hate to ask. You do have the bearings installed the correct way right? I know there is a radius on the side of the rod journal, and the bearings should have a matching radius. That would be best case scenario.

yea the tang on the bearing is in the slot on the rod. it kinda surprises me that the clearances are so far off because I used the bearings that eagle recommended and i'm not even close to having enough room for both rods.

 

[baddad457]

Do you have the rods turned the right way on the pistons?

 

[mikepotts]

before you do anything, now that i have thought more about it i would contact someone a ESP, and find out if there should be a need to have the rods machined, or if there is something else they could recomend to solve the problem.

 

[scotiascrapiron]

Do you have the rods turned the right way on the pistons?

the rods are on the piston so the bearing locks are facing the outside of the motor and the valve reliefs are eyebrow in towards the intake.thats right isn't it? a guy on another site suggested narrow bearings. How much extra clearance will they give me?

 

[mikepotts]

the rods are on the piston so the bearing locks are facing the outside of the motor and the valve reliefs are eyebrow in towards the intake.thats right isn't it? a guy on another site suggested narrow bearings. How much extra clearance will they give me?

actually that is wrong... the valve reliefs should be on the exhaust manifold side of the piston, think about it... the pushrods are on the upper side of the head (close to the intake), the valves are opposite, on the lower(exhaust) side of the head, angled out... again toward the exhaust, therefore when the valve travels toward the piston it would need the relief on the lower (exhaust) side of the piston.

as for the rods, ive always installed them with the stamped numbers toward the outside of the motor corrosponding with the side of the motor the rod is installed in.

does that make sense?

 

[scotiascrapiron]

actually that is wrong... the valve reliefs should be on the exhaust manifold side of the piston, think about it... the pushrods are on the upper side of the head (close to the intake), the valves are opposite, on the lower(exhaust) side of the head, angled out... again toward the exhaust, therefore when the valve travels toward the piston it would need the relief on the lower (exhaust) side of the piston.

as for the rods, ive always installed them with the stamped numbers toward the outside of the motor corrosponding with the side of the motor the rod is installed in.

does that make sense?

www.kb-silvolite.com/downloads/KB-Hyper-Automotive.pdf
this would be for the 351w

 

[baddad457]

actually that is wrong... the valve reliefs should be on the exhaust manifold side of the piston, think about it... the pushrods are on the upper side of the head (close to the intake), the valves are opposite, on the lower(exhaust) side of the head, angled out... again toward the exhaust, therefore when the valve travels toward the piston it would need the relief on the lower (exhaust) side of the piston.

as for the rods, ive always installed them with the stamped numbers toward the outside of the motor corrosponding with the side of the motor the rod is installed in.

does that make sense?

You've got it backwards. The valvereliefs used are on the intake side of the piston. The radius side of the rod has to be on the fillet (radiused side) of the crank journal.The numbered side of the rod does go toward the outside of the engine, that puts the radius side of the rod in the correct position with the crank fillets. If there's a notch on the piston top, that always is on the front, toward the front of the engine.

 

[mikepotts]

You've got it backwards. The valvereliefs used are on the intake side of the piston. The radius side of the rod has to be on the fillet (radiused side) of the crank journal.The numbered side of the rod does go toward the outside of the engine, that puts the radius side of the rod in the correct position with the crank fillets. If there's a notch on the piston top, that always is on the front, toward the front of the engine.

oh yeah, i was sitting on my head when i was contemplating the piston orientation! so i had it backwards.

 

[scotiascrapiron]

man you fellas are really being alot of help,it's nice to know that I can come here and get useful info. THANKS!! I called ESP today and their tech guy said the the narrow bearings should fix my problem. where I bought the crank needs to call them to,because they are the ones that recommended the wrong bearings in the first place.no milling on the rods but 3x the price for narrow performance bearings.

 

[mikepotts]

SWEET! glad you got some good info!


at least from ESP!

 

[baddad457]

You shouldn't need narrower than stock bearings at all. Unless the crank has narrower than stock journals