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MG Midget and Sprite Technical - Headgasket Picture

Just for you, Prop. Looks ok to me; maybe I didn't need to pull the head?
-Don


don g

hard to say Don...did you get the head checked out, the 25 psi in the last 2 cly was the reason to pull the head and that info came from trying to figure out why the engine is banging...is there damage to the rear of the head gasket between 3/4? it looks like it in the photo but cant be certian


Prop
Prop

Not sure which way round that gasket is but if the blown bit is between 1/2 then the banging is one cylinder firing, and blowing through into the adjacent cylinder whilst the valves in that cylinder are open,. Hence the BANG. And the negligible compression readings for 1 & 2.

Check with a straight edge that the hot gasses haven't eroded the top of the block where the gasket was blown. And if OK, then all you need is to replace the head gasket and torque it down properly. (don't be tempted to over-tighten beyond the specified torques)

Guy
Guy Weller

Prop... I was just joking. Did you look at the picture? it was blown between the 1st and 2nd cylinder.
don g

Cool Don,

I wasnt sure what i was looking at, it looked like a blown out section but my computer screen only recognises photos of nude girls...LOL

I dont recoginise the gasket... do you remember what it was... sorta looks like a fel pro...its not a payen


Prop
Prop

got it from vic british. funny, i ordered 2 in about a month or so, and got 2 different kinds.
don g

Don. I'm feeling really smug now. I said it was head gasket between 1 and 2 on the "engine banging" thread, which Guy agrees with on this thread. Seriously though I'm glad you got it sorted.

Bernie.
b higginson

Bernie-
YES- you should feel smug! You were 100% correct! So, another question that i'm too lazy to look up in the book for the answer...

New gasket... let it get warmed up, then retorque. do you let the engine cool down first? do you loosen 1/4 turn, then tighten, or loosen all 1/4 turn and tighten? do you put some miles on it first, or just let it idle till warm?

thanks in advance!

Don
don g

by the way, i've gotten all but one stud out of the engine block. i keep soaking with PB Blaster, then putting a vice-grips on it and hitting with a hammer. worked with the 3 other trouble ones....
don g

Crumbs- was that really the result of the head gasket blow????

i've never seen one that bad, it looks like it's been chiseled away!!



John...
j b biggs

Well then... ain't it nice to actually find an obvious problem when you're looking for one?

Best of luck with the head and block - hopefully the gasket is the only malady.

-:G:-
Gryf Ketcherside

Don,
Run the engine to temp, then let it cool overnight. Back off 1/4 turn and re-torque in sequence. Don't loosen all 1/4 turn and then torque. You might end up with some leaks.

BTW, your head gasket looks alomst as bad as this one...




Tim Michnay

Tim,

I can see that one vary clear...Is that copper gasket, Im pretty sure Ive neven seen one as bad as Dons, thats whay I want sure what I was looking at.

Prop
Prop

Tim,
you win. but, i might have an old one in the garage that's worse. if so, i'll take a picture. sounds like a new thread- "who has the worst headgasket picture"? No cheating, Prop.

Don
don g

Prop,
If you look closely, you can see it's an AF460. Also, it's hardly fair comparing Don's to this one. This is off the racecar. I think we'd have to have different divisions Don, depending on the type of car. The There would also have to be a separate category for Prop. I know he would find a way to outdo us all.:)
Tim Michnay

I hope I wont have to compete! hopefully 2nd times a charm LOL, looking like Ive about got these last issues resolved.

I got a bunch of new free time opened up as of today, looks like Im back on the midget agian, starting in the next couple of days

BTW Don,

Did you wrap the 2 studs I was discribing in aluminum tape to take up the slack in the 2 locating holes in the HG? I still thank thats a great idea willy had, The more Ive talked to various people over the past week and think about it, its easy to imagine the HG "walking around" as they call it.

I doulbt you had many miles on that last HG change, even though it was 3 years ago So i wonder if the gasket is walking around for you also....It will be interesting to find out if that was the source of the knocking you have been hearing over the past 2 years or so.

Prop...
Prop

Don. Tim's advice is correct. Follow it to the letter and you should be OK.
Tim. That's some blown gasket. I bet that was noisy!

Bernie.
b higginson

thanks again to all. got the studs, taking the head to the machine shop today for a look-over. should be back in business next week!
don g

I'd like to enter the worst head gasket competition. I pulled this one out of my MGA last Thursday. Apparently it blew in multiple spots many, many years ago. A flame cut valve, cracked head, and cracked piston went with this gasket. The engine still had 110-125 psi of compression.

You may notice a bulge between 2 & 3...


Kemper

It is a bulge and is what happens when the pressure can't initially get out. It ballooned the copper and the block side was filled with charcoal.

Still, not bad for 50 years of service on this engine.


Kemper

as usual Kemper

a stylish post

he he

and oh bloody hell

Payen next time round?

:)
bill sdgpm

This thread was discussed between 30/05/2010 and 04/06/2010

MG Midget and Sprite Technical index

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