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MGA MGA question - desperate

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TFR

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Need to find a person who is willing to talk to me about an MGA problem. I am the third person who has tried to remedy the problem and need some help.
It is a top end sound that can not be found. Need some ideas on whethe rthis is common or can be attributed to a certain area.

Please PM your number and I'll phone you as soon as possible.
 
TFR said:
Need to find a person who is willing to talk to me about an MGA problem. I am the third person who has tried to remedy the problem and need some help.
It is a top end sound that can not be found. Need some ideas on whethe rthis is common or can be attributed to a certain area.

Please PM your number and I'll phone you as soon as possible.
Click to expand...

How about explaining it to the rest of us. Who knows, you might get lucky. This site has people with expert advice on our cars from around the world. Waiting for a phone call from someone that knows nothing about the problem could be quite a lengthy experience. JMHO. PJ
 
Is it a consistent sound, or something that changes with engine speed? Mechanical issues such as too much of a gap between the rocker arms and valve. Head gasket/exhaust gasket blown possibly? Crack in the head or exhaust manifold? Give us some more details and let us help you sort it out.
 
Here's a quick explanation.

Engine rebuilt (complete top to bottom - professional engine shop (not british car shop)). After rebuild making top end noise. RATTLE, rattle rattle. Like ball bearings inside. Adjusted rockers three or four times. Still has the noise. When oil pressure builds noise is reduced. When rpms are raised noise becomes louder and louder.
Taking it to another LBC guy today.
 
I suppose that it might be noise from the rocker shaft. This was a known problem in MGBs and a factory service bulletin was put out about installing shims under the two middle rocker shaft stands. Barney has a mention of the shims on his web site https://mgaguru.com/mgtech/engine/ch105.htm but nothing on the service bulletin giving the shim thickness.
 
Given rising oil pressure is a factor in helping keep the noise down I would also suggest the area is rocker shaft related.

Get a mechanic to use a stethoscope on a running engine and isolated the problem that way.

Anyone else have any thoughts on this?

Pete.
 
Thats where I'd start. Also check the rocker bushings and shaft for wear and the rocker spacers/springs for gap or breakage. Can't remember which the A uses.
Also chect the pedistal bolt torque.
 
Guys I think my problem is the rocket shaft. It isn't getting any oil. Have not determined the reason but will in the next couple days.
Will post my findings.

Thanks for all the support. This is a wonderfull web sight.
 
Do you perhaps have a later B head on the engine? The design was changed and the oil holes at the rear rocker stand don't line up between the early head and the later rocker stands or vice versa. It's a pretty common problem that guys replacing cracked heads run into.
 
'specially if they aren't familiar with these engines.
 
Don't think this head is an old head. It has a "16" on the top. The holes align.

I discovered the hole change while thinking of buying B valve train parts. See that there is more then one type.
 
Well I got the oil to feed but it didn't remedy the noise. ARGH!

Now when test driving a freeze plug popped out. What the heck would cause that to happen.
 
The guy who owns the car took it to a shop where they decided the engine should be rebuilt. The shop in turn sent it to an engine rebuild shop. After it was reinstalled the engine made a rattle sound. The owner asked me to investigate the sound. I found the pistons in backwards and thought that might create the noise. They rotated the pistons and it didn't help.
The engine has new everything. The head and block were surfaced. The sleeves bored to .020" and new pistons. New, new, new.
I am still chasing the noise. Today while driving it to another LBC guy the freeze plug popped out overheating the engine. Making me have it towed in ($60.00).
ARGH! again
 
Just based on the problems you've disclosed so far I'd take it back to the engine rebuild shop and make them figure it out, plus do it for free. They probably charged a pretty penny for the parts and service. Hopefully there's some kind of warranty or guarantee of their work if nothing else.
 
Better have a look at the cam and lifters. Improper oiling, oil, installation etc will wipe a cam in very short order. Wiped cams on B series engines have a distinct rattling sound. If I remember correctly, at least some of the cam lubrication comes from return oil from the rocker hsaft. Also, when you got oil to the rockers, did you pull the shaft apart and look for damage? The freeze plug likely came out from improper fitting, or the wrong size/type plug being used. Check the area carefully for cracking (Worst case scenario) Ahh, the perils of haveing Joe Smallblock rebuild your LBC engine....
 
The rebuild shop had the engine twice and finally gave it back and ALL the money ($2500). So basically they have wiped their hands in the matter.
I'm on vacation next week so "out comes the engine".
 
Removed and disassembled the engine. The cam bearings were worn. Cam has some chattering marks on low side. The cam was tight in the bearings.

Looks like I'm going to replace the bearings, lifters and cam. Will post back on the results of the changes. If you have any other suggestions please post
 
A bit of a heads up: Those cam bearings will likely need aligned boring to size/tolerance after replacement.
 
Hmmm, chattering marks on low side... How about checking valve spring tension, and fit of valves to guides also. In fact, I would assume the worst case all the way through the engine. Check everything like it was a virgin engine that you had never seen before. I hate with a passion having to go over work I paid a "professional" to complete for me. If I wanted to babysit the job, I would have done it my self. The worst part is that with a string of evidence that you have now, you can have no idea what "smallblock Joe" might have screwed up. Sometimes the incompetant can be very inventive. Reminds me of the saying that you can't make anything foolproof, as they keep inventing better fools.
 
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