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1500 cylinder head

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terryke5hwe Silver Member Terry Halbert
Rogers, AR - Arkansas, USA   USA
1978 MG Midget 1500 "Midge"
1979 MG MGB "Money Pit!"
My 1979 Midget was running rough and oil is coming out the dipstick. Compression test not good, 90-100 psi. Pulled head today it was 23 degrees outside! Gasket and head doesn't look too bad and no scoring in cylinder's. Going to do a valve job and rings while I have it apart. Replaced oil pump and bearings last year. Can't afford a full rebuild right now. This should get me down the road for a while...

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jmac Platinum AdvertiserAdvertiser Jere McSparran
Greenup, IL, USA   USA
1971 MG Midget "Joy Ride"
1978 MG Midget "Therapy"
1978 MG Midget "(SOLD)"
Hey Terry, it's been a while since we talked or texted.

That head gasket doesn't look bad and I don't see much build up on your valves. I circled an area at your #3 cylinder, is that a crack or is that just a place that got scraped when you removed the head or the gasket?

I would suspect your rings. It would be good if you could measure the diameter of the cylinders and your pistons. If there is a difference of .0025 or greater it won't do much good in replacing the rings, the job won't last very long. Also, in order for your new rings to seal properly you should take a hone and bust the glaze on the sides of the cylinders. This will remove a small amount of metal and increase the clearance even more.

Good luck friend.



JMac
JMAC Engine Shop
http://www.jmacengineshop.com


Member Services:
Midget/Spitfire 1500 engine rebuilding.

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terryke5hwe Silver Member Terry Halbert
Rogers, AR - Arkansas, USA   USA
1978 MG Midget 1500 "Midge"
1979 MG MGB "Money Pit!"
Thanks for the reply! Waiting to hear from the machine shop about the head. They are very familiar with MG"s. Going to check the cylinder's for ring gap and was told to use a ball hone instead of the stones? I'm going to be very careful with the crank, I replaced the bearings and oil pump last summer..

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terryke5hwe Silver Member Terry Halbert
Rogers, AR - Arkansas, USA   USA
1978 MG Midget 1500 "Midge"
1979 MG MGB "Money Pit!"
Forgot to add that there were no ridges in the cylinder's, just carbon that I removed with some emery cloth.

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GeorgeOhr Nonya Business
Yes, confused, USA   USA
I had a ridge in mine and could see the rings and gaps I had so much clearance. My rering lasted about 30k so you should be fine

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terryke5hwe Silver Member Terry Halbert
Rogers, AR - Arkansas, USA   USA
1978 MG Midget 1500 "Midge"
1979 MG MGB "Money Pit!"
Got the piston's back in today. The machine shop cleaned them for free. Head will be ready next week. Doing this in-frame is a p.i.t.a. so much easier on an engine stand!

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GeorgeOhr Nonya Business
Yes, confused, USA   USA
I’d put flat tops in it if I were you

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jmac Platinum AdvertiserAdvertiser Jere McSparran
Greenup, IL, USA   USA
1971 MG Midget "Joy Ride"
1978 MG Midget "Therapy"
1978 MG Midget "(SOLD)"
Are you going to install new rings? If so, be sure to gap the rings. It is just a matter of putting the rings into the cylinder bore one at a time and then measuring the gap. 11/1000 (.011) is good. If it is too tight you will need to take a little off until it is. I use a fine grit wheel (bit sharpener stone) and twist the ring as little as possible; just enough that I can get the end to touch the side of the wheel. Then make sure there are no burrs before putting it back in the bore for a remeasurement. It takes time, but a step you don't want to miss.



JMac
JMAC Engine Shop
http://www.jmacengineshop.com


Member Services:
Midget/Spitfire 1500 engine rebuilding.
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