Mustang Tech

Been doing my head in this one. Built up a 347 using a new Summit 5.0 block, Scat forged moving bits. Ford racing X303 cam and FMS R302 roller lifters. Heads are AFR 185's and fitted with scorpion rockers. Required pushrod length checked and fitted all geometry is spot on. Start the engine and immediately there is a lot of clatter from the rockers. Started off adjusting the rockers with 3/4 turn from zero lash and have taken it up in quarter turn increments to 1.5 turns with no change in noise. The head, rocker combo was fine in the previous block with stock lifters. There is a HV oil pump fitted and plenty of oil is evident up top.

Any one have any ideas

Are they leak down lifters?

Factory replacements. recommended for use with the X303. I'm running the same lifters in my engine with no issues and the TFS cam I'm running is pretty much the same lift and ramp. Thoughts on using a set of the Crane 877 short travel lifters?

Nuts wrote:Factory replacements. recommended for use with the X303. I'm running the same lifters in my engine with no issues and the TFS cam I'm running is pretty much the same lift and ramp. Thoughts on using a set of the Crane 877 short travel lifters?

I normally buy compcam magnums I have a set of Comp short travel in the cupboard though

I might try screwing them down a bit more. If I have no success, i'll replace the lifters with some crane 877's.

1.5 turns is already quite a lot generally speaking. Should definitely be no play left in them there.
Were the lifters new, or from the old engine?

All new. Only real change from the original engine is the cam and lifters.

Years ago I bought the genuine Ford workshop manuals for a 1995 HO Mustang (mainly to reverse engineer the wiring).

The manual said to adjust roller lifters/rockers so that the pushrods still spin in the seat with no verticle movement and that's it. Are all of them clattering or just a couple of offenders?

I'm guessing you've done enough engine work to know the difference between lifter noise and exhaust blow-by?

BTW I used Eaton brand roller lifters in my 347 and they are fine. Apparently they are OEM anyway.

Yeah Luke, running almost the same setup in my engine and they're as quiet as.. I've built a few engine over the last 50 years and i've never had a lifter issue like this before. Screwed them down another quarter turn and it won't run so off with the manifold and we'll see what the hell is going on.. The block is a virgin block, maybe we've popped an oil gallery plug? Still getting plenty of oil up top though but maybe low on pressure??.. If I can't find anything i'll replace the lifters.

Here's a left field thought.

Are you sure its the lifters making the noise? I have had exhaust leaks on both banks of mine and each time would have sworn the racket was mechanical and metallic but turned out to be pneumatic. I eventually found them with a bit of hose in my ear as a stethoscope and once detected I could feel the air pulsing out at the leak location.

Just a thought.

rockers aren't touching an oil baffle are they

Both good things to look for but no cigar Guys. Geoff, no exhaust leak. And Shaun covers are clean. No interference between rockers and the valve spring retainers.

I actually though Shaun was on to something then, oh well. TBH I've never used conventional roller rockers. I've either had the Ford Motorsport ones you had to shim or the shaft rockers I have now which you can only adjust at the pushrod end.

Use Geoff's suggestion (hose or stethoscope) to ID what bank/s or cylinder/s are at issue and when you pull the manifold you will know where to focus your attention to ID the cause. OR ask to use JBB's ears as they found my 'dodgy lifter' that was the blown exhaust gasket.