• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

Lifter & Camshaft relationship

Share this page

nissanite

nissanite

Senior Member
Offline
Hello All,

This is just a story about my journey.
I am building a no compromise TR4 engine with 91mm bore & fuel injection. I know!
This is about camshaft & lifters. I ordered a cam & lifter set from vender#1. Decided to get a cam from accross the pond that would work better in an injected motor, vender#2. After installation & 30 min on the dyno, found the lifters not rotating in the bores. My engine builder stated this was imperative. The lifters already had formed a wear pattern & it was suggested they would fail. After other conversations with forums & engine builders everyone had a different opinion. I ordered lifters from vender#3 who agreed in the rotating theory.
Upon inspection these lifters had a slight dome on the surface (recomemended). These were installed & found they would rotate to a position, then stop. Further inspection found they had high & low spots on the surface. They would rotate to the low spot then stop, duplicting the first problem.
We had the cam ground again & had the new lifters surfaced properly & the now rotate without stopping. This shoud allow them to wear evenly & have a long life.
If you know of someone or are building a new engine I highly recommend that you mark the edge of the lifters, install with the cam & rotate before you assemble the rocker shaft. It may save you $$$$ & alot of greif.
My engine is going back together this week & should be on the dyno by the end of the month.
 
Didn't we have a lifter rotation problem a while ago?
Seems it is a good ideas to check. How hard is it to do this?
 
This has been ongoing for a while. The problems have been finaly solved.
When you buy new parts you do not assume that they bad.
I am now reconsidering that last sentence.

There are many different opinions about this issue.
 
nissanite said:
There are many different opinions about this issue.
Click to expand...

I think the most revealing comment was made by Greg Solow, who is a professional rebuilder of TR engines (well, Morgan mostly, but close enough). He stated a few years back that he now does 100% inspection of new lifters, and finds a few bad ones in every batch.

The crown is easy to miss if you don't know to look for it, but not hard to check. Just hold a good metal straight edge up to the bottom, and look for light near the edges.
 
Chris Marx found the European cams are ground flat where the American grinds have some taper.

We're using tool steel lifters that Greg Solow had a small batch of. We're still using welded/reground stock cams. The timing gear on the new blanks is hobbled wrong, imo. We're still breaking reground cams at the timing gear due to the base circle having to be cut down.

Try APT, I believe they check their lifters before sending them out.

When pushing these engines to the limit (over 7200rpm), the valvetrain is the weakest point, especially the camshaft. Out of the last 5 events, 4 have been DNF due to some issue relating to the timing gear / distributor drive gear. Either the camshaft breaks, distributor breaks, or the drive gear gets busted. We suspect this is because the cam is bouncing around at high revs. A real billet cam is the answer, but most Triumph people are cheap, and wouldn't want to shell out the dollars for one. It's too cost prohibitive to do alone.

My .02
 
Not having done a TR engine in years, it may be a dead end, but Crane Cams has reorganized and ~may~ be a source for cams/lifters of good quality. They do still offer the MGA/B line. Worth an e-mail or call, at least.

JMHO
 
Back
Top