Valve lifters wrecked again!

[Amphibian]

First post here so please be gentle! Interesting problem for you. This is about my 998cc Sprite engine.

The valve clatter just got intolerable again. Pulled out a cam follower (lifter I believe to you guys over there). Same old problem. Face eroded and vertical score marks on the sides. This is 3,000 miles after the third rebuild in 13,000 miles. Cam is a new (or was) Kent 276, new Minispares followers, new cam bearings, lube used on assembly, broken in exactly as per Kent instructions. No spring binding, clearances exactly to spec (but now impossible to keep right of course). Rocker bushes checked and OK, geometry adjusted by shimming the pillars. Oil is Duckhams 20/50, and gives 60 psi hot with a 10-row cooler. What more can I do? I have gone through 3 cams so far. Never had any probs like this over the last 40 years with A-series lumps. /ubbthreads/images/graemlins/frown.gif

 

[GB1]

A few questions?

How much pressure are you running cold?

How do the cam journals look?

Are the valve springs upgraded?

Do the followers have oil holes drilled in them?

Patrick

 

[spritenut]

276 cam should have rockers set at .016, not .012.
Are the cam bearing oil journals lined up with the block borings?
1275 pushrods in a 998? They are taller.

 

[healeyneil]

For what its worth, there have been problems with cam followers in big Healey engines. Modern made stuff just not as good quality as originals it would seem

 

[Bugeye58]

Do you have any idea of the spring pressure and installed height?
Jeff

 

[Hap Waldrop]

Alot of the low end lifters plain and simple are junk. Also if your Kent cam was a rigrind then chances are it is not hardened. See what Mini Spares has in a hardened (nitrited) regrind or go with a billet cam, then buy the best lifters or you chaps say tappets, either the MS lighten lifters ( they check out to about 57 Rockwell C) or the Chilled iron lifter, or source a set of APT lifters in California. Bottom line new stock lifters are junk, reground non hardened cams are junk, you need a hardened cam and lifters that spec close to the same Rockwell C. Since you are in the UK, I would buzz Kieth Calver, he'll put you on the right path to what parts to buy. Keith Calver and Peter May are both knowledgable buildiers in the UK and can source you the correct pieces and get you on the right path.

 

[JerryB]

""""""vertical score marks on the sides. """"""

in addition to the above sounds like you might have an oiling problem.

have you driven out those silly brass insert plugs in
the oil galleys and given the galleys the scrubbing?

Oil pump functioning well?

 

[Amphibian]

Thanks guys for all this. Answers as follows:

Lifters were not drilled. I've seen conflicting opinions on this point.

Oil gallery has been scrubbed to death!

Oil pressure is 65 psi cold, 55-60 hot.

Cam journals are fine - bit polished on the thrust side. Oil holes correctly lined up - the problem is with lobes not bearings.

I am using 1098 conrods.

Clearance always set to 0.016".

Don't know if Kent cams are hardened. I will ask them.

There is no coil binding - head was set up by local tuning shop and they looked up the correct springs (supposedly). Kent doesn't supply spring data other than which of their own springs to use.

The cam lobes were down about 3 thou, with one exhaust lobe down 5-6 thou so I have replaced the cam with a new one - Kent again. This was not exchange so presumably it wasn't a regrind - I'll check with supplier.

Have now fitted Isky type lifters from Minispares which are lighter and look much better made.

All going back together now.

 

[jlaird]

Keep us updated, a very intresting problem.

 

[Hap Waldrop]

Unless Kent has changed, they use unhardened regrinds, which in my opinion is a recipe for failure. If you got a billet cam you will know it, by price alone. Nitrited regrinds work fine but most don't bother with this for profit reasons. For the street I'm pretty much plugged into using APT's billets and a few of his nitrited regrinds now, atleast I know I can trust David and his products.

 

[jlaird]

Hap, what should a GOOD street cam cost, ball park only please.

 

[GB1]

Jack:

My cam from APT cost $212 and the followers were $98.

Patrick

 

[Hap Waldrop]

[ QUOTE ]
Jack:

My cam from APT cost $212 and the followers were $98.

Patrick

[/ QUOTE ]

That was a nitrited regrind then, which is fine, you can trust David to shoot you straight. The problem with the nitrited regrinds is you the grinder has to source cores, so this will become a thing of the past in the future. David and I had a good talk this week about this, he says he been getting alot of garbage in for cores which are costing him money because he can't use them, so in the future expect it to be billets only, which depending on the cost of stele will run you anywhere from $300-400, but you geting what you pay for, and always with the hardened or billet cams use a good set of lifters like the APT units.

Patrick, what you have should work wonderfully and you bought them just in time as David is getting ready to have a price increase if he hasn't already done it.

 

[DrEntropy]

I think I heard Jack pounding the telephone keys from HERE! /ubbthreads/images/graemlins/jester.gif

 

[jlaird]

Naa Doc. Jack is going to get everything up and running then work on a very warm street engine that looks stock on the outside.

 

[GB1]

Hap, thanks that is interesting. They charged me a $10 core charge and I told Phil it wasn't worth sending my core back for that price.

Patrick

 

[Amphibian]

Sorry folks, I keep forgetting to check back here. Thanks for all the advice. I have put it all back together now with a new Kent regrind (which I had already bought before hearing all the tales of woe about regrinds), and the Isky-type nitrided lifters from MiniSport. Fingers crossed! If it happens again obviously the only next step possible is a billet cam. But essentially the wear has been far worse on the lifters than the cam.