MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - Cam Lift

I used a dial indicator to measure the cam/lobe lift and these are my results.

1-.220
2-.205
3-.220
4-.223
5-.219
6-.220
7-.221
8-.218

Number 2 is about .015" below average. It shows no pitting or obvious wear.

I will be replacing the lifters with new ones.

I'd like opinions here as to using this existing cam for the re-build.

TIA,
Mort

Mort 50 TD (Mobius)

Mort,
My opinion is to grab a roller lifter package while you can. I did. You won't be asking this same question a decade or two from now when considering the next rebuild. Those roller lifter setups, like superchargers, may not be readily available next time you want one. You may be really sorry later that you reused your old cam, but you won't ever be sorry going to one of Len's babies. Plus, you'll get that extra gusto, to boot.

With #2 down .018" from #3, I have to wonder what the original lobe lift is, and what they all wore down. I'm going to try to remember to mike ours today at work to compare notes. How frequently did that one valve clatter and need attention? You could be facing disintegration at an exponential increase and the thoughts of changing a cam later isn't very appealing, especially after all those other shiny new parts have run with iron particles & "fines" circulating in the oil. I put 4 low power speaker magnets in the sump when I overhauled this one engine a dozen years ago and they were covered in iron fuzz. I think this time I'll throw in some neodymium magnets and also attach one in (or on) the 1 gallon spin-on filter that's in the works, too.

You know there are two different lifter profiles for the different cam grinds. If you guess wrong on the type of cam you have, the results will not be to your liking. Yesterday, I mentioned in another thread that I'm willing to bet .012 and .019 lash cams have virtually the same lobe lift and the increased valve lift results from the .007" reduction in lash. Can someone else provide evidence to the contrary? Please do!

Remind me, is yours supercharged? One of Len's grinds is the only one cut specifically for a supercharger on the street. The minimal overlap was a really appealing feature to me. I might install another one in our '51 with a Marshall even though it is officially retired for now.

Opinionated JIM

JRN JIM

Mort,
I chucked our used cam into the lathe and used a dial indicator to come up with the readings very similar to yours: .212" .216" .215" .220" .200" .222" .218" .209"

Again, there's no identification on the cam. The engine had been rebuilt prior to our owning the car. As it had the coffin valve cover, there's no tag for valve lash to lend a clue.
JRN JIM

Jim,
You have a high of .222 which, using a 1.5 rocker ratio would give you a .333 valve lift. The numbers are not precise but that would indicate a later cam.
Your low of .200 gives about a 10% variation. I'm sure any competent engine re-builder would regrind or replace our cams. Since mine is still in the car and I only have a low on one lobe, I am thinking about leaving it alone. If I pull it I would go with one of Len's roller lifters and cam ground for the supercharger.
Decisions, decisions.

Mort(Too lazy to pull the engine and do it right)
Mort 50 TD (Mobius)

Any one who can remove the pistons & rods & re install them, in a T car with the engine in the chassis, can install one of my roller cam kits without removing the engine.
Len Fanelli

Mort,
I posted this in another forum for an owner of a supercharged TD asking about Len's cam package.
For what it's worth...

"Should I get Len's cam/roller kit?" I did.

Len has cam grinds specifically for supercharged engines. I have the "street supercharged" grind going in this winter. It has very little overlap (and enjoys longer exhaust, too), which is very important to myself so very little charged is blown out the exhaust under boost. That translates into better power and fuel mileage, and hopefully will cut down on the engine compartment and footwell temps. The TDs are my wife's toys and at 80mph and 4psi boost, my feet can get scorched on the passenger side, the engine compartment gets that hot (even with the exhaust pipes covered with flexible stainless tubing). I recently installed a thermocouple to measure exhaust temps with stock cam vs Len's, but the early winter set my plans back for test rides with the existing camshaft.

Of course there are other important benefits, like more power WITHOUT long durations, so it idles and runs at lower RPMs smoothly and provides a strong midrange. With our MGB 3.9:1 gearing, cruising at 60-80mph/3000-4000rpm is in the midrange and not peak power.

Also rollers will eliminate the threat of catastrophic flat lifter & lobe wear associated with our modern oils, especially if stronger springs were installed. This isn't just an "old MG engine" problem. A buddy recently rebuilt a small block Chevy engine, and on initial startup, he adjusted the hydraulic lifters, then readjusted as they started to clatter, then again and again... the lobes worn down in a matter of minutes wasting that freshly rebuilt engine.

I've got no affiliation with Len, just posting my 2 cents worth. Am also contemplating procuring another set while they're still available (we have a retired '51 just setting around with a Marshall).
JRN JIM

This thread was discussed between 16/01/2014 and 18/01/2014

MG TD TF 1500 index

This thread is from the archives. Join this live forum now