The V8 Owners Forum -

Hi,

I am doing a trial build of my 5L engine with Wildcat heads from Lloyds and Kent M238 cam.

With the pushrods Lloyds supplied (3/8ths, 8.8" long) my valve gear binds up. The pushrod binds up against the rocker body, and the pushrod looks to just graze the pushrod hole.

With the lift of the M238 cam, I suspected my pushrod was too long, so I bought a 5/16ths adjustable test pushrod. I think 8.7" rods will work. I think 3/8ths will also bind, so I ordered 5/16ths rods and new Chevy SBC guide plates, assuming the Wildcats used Chevy gear. ( To get optimal rocker geometry, I think my pushrods need to be longer than 8.8, but that won't work, so just getting clearance is the goal).

The new guide plates don't fit. The fixing centres and pushrod centres are further apart than the guide plates supplied with the heads. Not sure how to post an image, otherwise I would.

Has anyone with Wildcat heats encountered this? Are the guide plates perhaps Ford items, or are they custom made? The fixing centres are perhaps 1/4inch further apart.

I'll call Lloyds tomorrow, but hoping someone can give me some insights here?

Can’t help with the guide plates, but did Lloyds supply the cam,followers and push rods ?
As not all makes of followers are the same size ?
Did you get this resolved ?

Hi,

Thanks for the reply. Lloyds did supply the pushrods, but not the followers and cam.

I did get the binding issue resolved by using 5/16ths rods and adjustable guide plates. I had to modify the guide plates slightly to allow for sufficient adjustment to get the correct pushrod centre-to-centre distance, but I think the binding issue is resolved. I have read that some builders like to put a spot of TIG weld on them once the plates are adjusted -- not sure if I shall do that or not yet.

However, it turned out I had additional problems.

Lloyds informed me that ACR (where Lloyds sources them) changed the design of the heads to be speced for roller cams only, and it turns out my set were indeed speced for a roller cam (didn't tell me that when I bought them). He said my spring pressures would be much too high. I think I identified which springs I have installed on my heads (and I took a very crude measurement with bathroom scales), and I concur that the spring pressures are far higher than those Kent recommends for the cam (60lbs closed and 224lbs open, compared to 120lbs closed and well over 300lbs open with the springs supplied with the heads).

Roller cam not in the budget (spaffed it on brakes ), so I have had to find suitable softer springs. I have had some spring locator/spacers made to get the correct installed height for the springs I have opted for, and waiting for these to be delivered. I am not worried about the narrower 5/16ths pushrods with the spring pressures I am expecting now.

Also, I didn't realize I needed Chevy lifters due to the pushrod ball end diameter (5/16ths chevy v 3/8ths Rover), so have purchased new lifters.

Everything clears, and my rocker geometry will have to be what it is. My contact pattern is centred on the valve stem.

However, I have read conflicting views on what constitutes correct geometry.

A) Some builders say the roller should contact the valve stem just inboard of centre when closed, be just outboard of centre at half lift, and return to inboard of centre at full lift. That makes sense to me, as that minimizes the movement across the valve stem.

B) Others (including Real Steel) say that the roller should be inboard of centre when closed, centre at half lift, and outboard of centre at full lift. This is exactly what I have achieved with my current solution. This makes sense to me for a non-roller lifter.

To achieve scenario A, my pushrods would have to be much longer that the ones Lloyds supplied, which would certainly bind up. My geometry is consistent with scenario B), which e.g.Real Steel recommend on their webpages.

Which view is correct?

You and real steel are right !
You do seem to be having a run of bad luck.
When I bought my TA heads, I had the valve pockets machined for a roller cam, but springs put in for a solid cam, then when I had enough funds, I just had to change springs,retainers,p/rods etc, and my geometry was good to go, You should of been told springs were for a roller cam, huge difference in pressure,
you can’t supply push rods without knowing what lifters are going in
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