T-Series & Prewar Forum

I recently started my TD for the first time in many years. Removed plugs, primed oil pump, filled oil filter, pressure fed oil to head then turned the engine over for about 20 seconds to verify I had oil pressure before firing. Pulled the starter knob and she fired up in seconds, registered 45 psi oil pressure and ran for 15 minutes or so at 1,500 RPM before I shut it down, satisfied everything was ok. There’s more issues in the startup story that can wait for another post.

The engine was rebuilt over twenty years ago. Like most folks, I replaced the cam with the only available option from Moss Motors in 1999, the Crane cam (451-260) and shorter push rods (433-335). FYI, I purchased the cam from Checker Auto Parts for $189 rather than $239 at Moss.

At some point, possibly 2010, Moss started selling modified tappets (current part # 433-365) to go with the Crane cam. The claim is the cam does not have a flat profile and crowned tappets are needed so they will rotate properly. More importantly, the modified tappets have enlarged oil holes to improve cam lubrication. By this time, my engine had been reassembled using new but original style tappets. I simply missed the information about the modified tappets and I now fear I might have a problem. All this has created a raft of questions.

Has anyone had success or problems using a Crane/Comp cam with flat tappets?

Can I pull the tappets I’ve installed and replace them with the modified tappets? I’m assuming the shorter pushrods I installed with the cam do not need to be replaced.

Crane recommends the valve lash is set HOT as follows: intake .018, exhaust .020. They also recommend adding .002 if setting the valves COLD. Has anyone setup a Crane cam with these settings?

Crane also describes a laborious procedure for setting valve lash. Basically, it ensures the tappet is positioned on the cam base circle. Doesn’t the procedure described in the MG Workshop manual do the same thing?

Thanks in advance for any help!

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Gregg
1950 TD #1844
A Lifetime Project

My 55TF is set up that way. I followed Cranes suggestions on installation. That was about 10 years ago and it runs great. PJ

Did a TF 1500 engine around 1989 with one of the first large lobe Crane cams, and whatever tappets were supplied then. Very few miles on the car since then, valves sound great and last time I adjusted they were perfect. I put a Crane "original replacement" cam from Abingdon in my engine around 20 years ago. Not large lobe, but same .018-.020 clearance. Works fine. Follow manufacture's clearance specs to adjust. I have always used "rule of 9s"- ie adjust 4 if 5 open, 1 if 8 open, etc. George

Moss was selling the crowned and modified oil slot tappets in the early 2000's as that is what when in my TF. My experience of running the engine pretty hard says you can expect this after 10,000 miles. A second new set of tappets with the same cam went in at that point and after 10,000 miles the tappets were again going south. This time I sent them to Delta Cams were they did their magic. After close to another 10000 miles they looked like the last photo. At this point I rebuilt the engine with a new cam and set of tappets. The rods I used call for a good deal for side clearance and I expect they are throwing a lot more oil around the cam. Will they last any longer? Probably not. Just my experience with them. And yes the cam was broken in properly and Valvoline 20W 50 racing oil was being used with regular oil changes.

The issue with the Crane cam is the ramp design - faster ramps allow you to build much higher cylinder pressures than a traditional cam design. This places much higher stresses on the lifter faces, so proper hardness lifters is key. Moss lifters are soft, as are most. Look for a good set of hardened lifters built for racing applications. Manley Ford may be a good source? Rockwell 55 is about where you want to be.

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jeff@advanceddistributors.com

Ran across this on a Facebook post from an AMC restoration company: "Similarly, there are only a couple of camshaft manufacturers remaining that harden their cams correctly and nearly all flat tappet lifters are now such terrible quality and inconsistent hardness that we are no longer willing to risk losing a cam due to poorly made cams and lifters. In fact, we now only use either rollers or custom ground flat tappets with Johnson made lifters from Howard or Herbert. For example, we have probably used 50 or more Summit cams over the past 15 years but the last 4 we used did not even make it through break in so they too are now off the list of acceptable quality parts as well." So not just MG issue. George

See what Newman Cams UK have to say about performance cams and hardened followers.
Dave H

Newman Cams are currently on my "do not use" list. The last cam and lifters I ordered from them had multiple serious issues and failed in 30 minutes. I made the reseller aware, and it turns out every engine he pulled apart that had one of those cams had the same problem. People were driving around on disintegrating lifters without even knowing about it. This is why you always check for correct operation and break-in. Don't just drive along and assume everything is fine.

It's been a few months so they may have corrected the problem by now, but I haven't used another one to confirm.