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MG MGA - Engine Rebuilding Time

You saw it coming didn't you?

Many thanks to Mike Parker for the heads up to check the block deck for damage. Sure enough there is straight groove burned from cylinders #2 to #3. You can even see it in the attached picture.

So out comes the block. My machinist wants the block stripped down for planing.

So I'm pretty much forced to go with a rebuild.

Here's the to do list:

Port and polish the head. Bronze valve guides. Stellite exhaust valves. Tidy up valve seats (which look fine)Tidy up intake valves. New heavy duty valve springs.

Deck block.

Hone cylinder bores

Replace piston rings.

Upgrade to fast street cam.

Replace 3 main bearings.

So some questions:

1)Do I have to be concerned with the bore honing? Meaning; how many borings before I have to go up in piston size?

2)is the Moss Fast street came still the way to go or is there a mor current preferred suggestion.

3) I understand that a fast street cam calls for a higher compression ratio. What is the recommended ratio?

4) I've read that Moss' standard stud set is of questionable quality. Is there a recommended alternative? I don't want to go to the extreme of getting ACP's competition stud set for $130 if its not necessary.

Anything els?

T McCarthy

Don't forget to have hardened valve seats installed for the exhaust valves, makes it a no lead head.
The bores needs to be checked for taper, if they exceed the specs (usually about .003) they should be bored and then honed, oversize pistons fitted. Don't forget to add rod bearings and cam bearings to your list. Check the timing chain and gears as well as the sprockets and tensioner. New oil pump.
Make sure your machinest does not grind the rear scroll of the crank or the block area adjacent to it. The Moss cam is a Crane Cam, works fine in ours. A higher compression ratio is not a requirment, the cam is not that hot.

Make sure the block is spotless when reassembling. Oil passages make great hiding places for little pieces of gunk that can wipe out a new set of bearings in no time.

Since your already in this far, do it right, don't skimp. On the other hand avoid putting in every gee wiz gizmo you might read about unless you are racing on a track.
J Heisenfeldt

Make sure your machinist is aware of the tolerances needed to make the bronze guides work, otherwise they'll stick.
Mark J Michalak

This thread was discussed on 11/08/2008

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This thread is from the archive. The Live MG MGA BBS is active now.