carpunk

im gathering bits for my build and have been checking out old threads here
is there a problem using fomoco bolt on 1.73 roller rockers and a solid f246 crane cam? also i have adjustable pushrods are these ok or should i junk them for normal type(lash adjustment?)
its not an out and out racer but any advise?

xdclevo

I used adjustable pushrods once many years ago. I had them for 1 hour. They break easily. Right on the threads. I will never ever use again.

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

brenx

You may get a flex issue in the unbrako due to the spring pressure required for an F246. Guideplates will help but for how long I don't know.

__________________
XB Fairmont (street car) 11.07@123.02mph.

carpunk

my ford r/rs dont require guideplates and the engine has ran for years with adj p,rods i was just concerned the solid cam may change things?
if they are so crap why do they still sell them?
maybe some of you are running overly strong spring rates?
i had a straight six motor a while back with over the top springs and the tops of valves were beaten over like the head of a well used chisel!
what rate does the f246 require? there nothing to gain from springs stronger than they need to be

brenx

They aren't crap the mounting bolts (5/16th unbrako's) can't handle the spring pressure.

__________________
XB Fairmont (street car) 11.07@123.02mph.

carpunk

sorry im a bit lost are you tralking about adj p,rods or the ford rr,s?
is there any problem running my ford rr,s with this solid cam?
whats unbrakos? iv never heard that b4

brenx

Roller rockers. Bolt on adjustable ones don't like the spring pressures used on solid cams. The 5/16th unbrako's fail due to flex. An unbrako is the 5/16th bolt that holds the RR to the head.

__________________
XB Fairmont (street car) 11.07@123.02mph.

xdclevo

Is STROKEXD using 5/16? I can remember somewhere reading it a while ago. He may be able to let us know how they went.
I, like brenx would prefer the 7/16 screw in stud type for a solid cam with 570/590 lift.

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

TruBlu351

He's got the bolt on Yella Terras with 5/16 standard size bolts.

The rockers themselves are bullet proof, but they're only as good as the weakest link (5/16 bolt). IMO it's worth the extra few hundred $ for head machining and guide plates.

I'd recommend the stronger 7/16 screw in studs too. I've got some gold crane ones.........just need the studs.

__________________
XE Falcon
393 Tremec TKO 9"

brenx

The beauty is stud mount RR are cheaper than bolt on versions. The savings there pays for the machining etc for stud mount RR's.

__________________
XB Fairmont (street car) 11.07@123.02mph.