MG-Cars.info

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

Recommendations

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 MGB Technical - Camshaft swap on 18GB engine

While looking for some lost horses Peter Burgess suggested the Oselli reground cam might be a bit worn. He seems to be be right as I got between 8 and 9 mm lift measured on the valves. I couldnt find data for that cam but Piper fast road "270" cams seem to be closer to 12mm. I was going to get a Piper 270 and followers of course from Peter, I also looked through the archives here and the workshop manual and it seems as though for the 18GB engine its an engine out job. Is that right? If you can do it without I would appreciate any guidance. Thanks guys
(compression and all leak down test are fine and Aldon set it up on the RR laast year so the camshaft makes sense)
Stan Best

Stan-
Yes, you'll have to remove the engine in order to replace the camshaft. I had a Piper 270 camshaft in the original engine of my MGB and found that it delivered spirited performance while retaining easy starting, a smooth idle, and a nice, wide powerband.
Stephen Strange

I had a friend who replace the cam with the engine in place, but for all the work he had to do to accomplish it, he would have been ahead of the game to have removed the engine. Cheers - Dave
David DuBois

I have done them without removing the engine but the engine must be jacked up, engine mounts disconnected and sump removed so not a lot in it time wise and you can do a few extras that you may find necessary with the engine out. Denis
Denis4

Thanks guys, that stacks up with all the written advice that its unavoidable and so out it comes.
Stan Best

Stan, I have a Crane 270 in my 1979. I get a good power band from 2500-4000 and a smooth idle. I also run the car on regular unleaded fuel. I vote yes for a 270 cam

FWIW

cheers

Gary
79 mgb
gary hansen

I put a Kent 718 (Rally, I think) cam in my 18GB engined car with the engine in situ. Agree with all that's been said. Hauling out the engine is just as easy. Plus, you've got to remove the rad/diaphragm/oil cooler whatever you do. The only difference is one doesn't have to undo the bellhousing to engine bolts.

Peter
P A Allen

Don't mean to be a fly in the ointment, but I recall a comparative review by Doug Jackson years ago condemming the Kent cams as lifter eaters. Of course, I could be wrong. The P-270 and P285 are amazing cams. I ran the 285 for 8 years and idled around 650-750 without any lumpbosis. It pulls like a freight train from 3500 up! Cheers, Vic
vem myers

Then again modern oils with low ZDDP are said to be a cause of rapid cam and lifter wear.
Paul Hunt

I've had a Kent 280 cam, in my GB block, going on twenty years now. I rarely have to adjust the valves and the performance is excellent. RAY
rjm RAY

Well there you go then Ray- Good news. I am first time trying the Burgess suggested P255 on the new SC rebuild. The "racing" oils have ZDDP, and cheaper than buying a bottle from Moss. Vic
vem myers

Vic, I use Castrol 4T 20W50 motorcylce oil that has a very high level of ZDDP. I'm sure that it has helped to minimize the amount of wear on the faces of the lifters and cam. RAY
rjm RAY

This thread was discussed between 11/05/2013 and 29/05/2013

MG MGB Technical index

This thread is from the archives. Join the live MG MGB Technical BBS now