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Engine timing

Falkon

Senior Member
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I will soon be putting my engine back together. I was wondering and wanting advice on how to match the timing up on everything. I know a little about timing the engine but not much. ANY advice would help. :thankyousign:
 
Do you mean with the timing chain, or perhaps static timing the distributor?
 
Best "first move" is to find a Bentley Press "Complete Official MG Midget" repair manual. Amazon or E-Bay. It's a nealy exact copy of the original workshop manual and is an invaluable resource for repair info. Haynes/Chilton's etc. are okay but have some inaccuracies.

Welcome to the Form, lots of folks here to help guide you.

Is this a complete down-to-component level rebuild you're doing? Machine shop for the cylinder bores, crank polish/undersize, and so-on?
 
yes it is a complete engine rebuild. everything is being done. I just ordered all the parts i need and once i get them all ill have left to do is put it together and get the head cleaned.
 
As a word of advice, be sure to check EVERYTHING for correctness. Micrometers to check that the crank journals are done to the proper diameters, piston to bore clearances are right, etc. Doing this will greatly enhance the chances the thing will run reliably for years.

In a nutshell, final assembly would go something like:

insert cam first, crank next, piston/rod assemblies, oil pump, timing jackshaft, degree the cam/crank sprocket & chain assembly then the pan/timing cover, etc. Lifters, head, pushrods then valve train assembly.

More things like the distributor, water pump, valve adjust and cover, backplate, etc. can be in about any 'order'.
 
Be sure you have the machine shop surface the head AND the block flat while they are working on it. Not doing so has led to a lot of trouble for a lot of folks rebuilding brit engines. If it is'nt done one is inviting head gasket problems.
Kurt.
 
I have to echo Dr. E. If you have a good shop manual, all this will be in it. If you don't, you really need to get one before putting the engine together. These engines are not terribly complicated--but, still, your chances of doing everything correctly, without a manual, are pretty near zero.
 
nomad said:
Be sure you have the machine shop surface the head AND the block flat while they are working on it. Not doing so has led to a lot of trouble for a lot of folks rebuilding brit engines. If it is'nt done one is inviting head gasket problems.
Kurt.

Well that only applies if the block deck is not straight, a straight edge can be used for checking that. Machine work should be done because it is warranted, not just because.
 
:iagree:
 
Guess I did'nt phrase that correctly, Hap, of course it needs to be checked with a straight edge but my experience has been that both need to be surfaced on the brit engines I have had experience with.

Blocks and heads, as you know, tend to change with age. I have always heard that if you are setting up a performance engine it is best to start with seasoned components. Don't you agree?

Kurt.
 
Kurt, I build a dozen or so LBC street engines a year, and most block deck check straight, and don't get decked on street engines, and never give a problem. The main reason we deck the blocks on the race engine is to get them to shorter deck height to increase compression ratio.

I don't know about the seasoned part deal, we build race engines sometimes with brand new billet cranks, new Carrillo/Pauter rods, the way I see it when you build any engine, you measure, remeasure and then measure again. So for me, it not about doing machine for the heck of it, it about making sure every clearence/surface is dictated and checked to be sure thats what it is.

The deal with our blocks is they are very high quality, MG block have some of the highest nickel content of any block made.

The deal for me is to blueprint every engine regardless if it's stock street engine or a full out race motor, I probably have $5000 worth of measuring tools to do this with, just my Sunnen rod gauge was almost $2000 by itself, but it was necessary item for me to have. My background was building race engines, street engines came along as byproduct of that, and I use the same blueprinting methods I do for the street engines as I do for the race engines.
 
Hap;I realize you have a lot more experience with these engines but I seem to remember from long ago that if you were building an US V8 a seasoned block was a good thing to have. As to my limited experience with MG engines I've done 3 B serie's that all needed to have the block trued cause it was low in the center. I just threw away a 1275 that PO had built. It was low in the center of the block and the head was'nt true either. Fitted with a copper head gasket it leaked between 2 and 3 till the block and head were no good. I replaced with a used 1275 that I had. I worked the head and had it skimmed flat but did'nt do the block since I did'nt want to tear it down. It was OK but light could be seen under a straight edge in the center of the block. I did'nt use a copper head gasket since I believe a composite gasket is probably more capable of fitting into uneven surface's.
Just my limited experience so far. On B series engine's I believe I would have both the block and head skimmed just enough to make them flat as a matter of course. On A serie's I think I would have it done on the hotter engines unless they checked nearly perfect.

Just my .02 :smile:

Kurt.
 
Kurt, I use a .0015" feeler gauge to check the block with a Starrett straight edge, if they pass the .0015" they don't get decked, unless that is part of the game plan to raise the compression ratio. On head gaskets, I go for the composite gasket everytime, and always Payen, they are far superior to the copper gaskets. I've also had really good luck with high compression 1275 race engine using the Cometic head gasket, we used the sucessfully with compression ratio as high as 15.5 to 1, it's overkill for most street engines, but they can sometimes be a lifesaver if you have some block deck iregualarities.
 
Thanks Hap, not familiar with the Cometic but have used the Payen. Now I know where to get one!!

Kurt.
 
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