P38A Feckity feck!

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martynv8

Well-Known Member
Posts
2,258
Location
Sheffield
OK, here goes.........

So after spending a fortune in May last year on a top hat block, new pistons, crank etc. All was well with the rebuild until October when the LH Bank head gasket gave way (stretch bolt had eventually pulled a weak thread between cyl 5 & 3) & got a blow out between the 2 cylinders causing one hell of a misfire.
So, i had the offending thread in the block helicoiled & head checked & skimmed. All went back on....all ok......until now.
Noticed a 'chuffing' from the engine yesterday so had a look around. First of all oil just registering on dipstick (& i do check this at least once a week). Looked underneath to see the sump & bellhousing covered in the stuff. Topped up oil & took a closer look at things. Taking the oil filler cap off whilst engine was running & was met with what resembled a locomotive chimney...exhaust gasses chuffing out. So, I have exhaust gasses getting into the valley. A closer look underneath & i can see gasses bubbling out between the head & block around the middle cylinders. I guess the huge addition to the manifold pressure is causing the major oil leaks from the top end?
In the 4 years i've had the P38, this is the 4th HG failure across 2 engines despite meticulous maintenance.

So, what to do????
Head says : call it a day on the old girl & move on & stop throwing time & money at what is a very tidy P38 but with a pretty big achilles heel (the Rover V8 engine). It would be a huge shame to sell as spares / repair especially as everything else works perfectly (well, apart from some dodgy pixels on the HVAC display).
Heart says : strip it down myself & see where the fault lies this time. At the moment i'm suspecting that maybe the original block may have had a few too many head changes in it's previous life & the threads are starting to weaken, or of course the helicoil may have failed?

Apologies for yet another HG Fail thread!!.......:(
 
My heart goes out to you mate.

If it was me.. and I had the space, i'd be stripping it myself for investigation and rebuild.
 
Do the heads yourself. I would say that though, to try and legitimise my own stubborness!

I'd even think about Helicoiling all the block threads. Doing it yourself might only take a day, and at least you'd know the threads were strong.

4 in 4 years across 2 engines has go to be either unlucky, or something else is wrong no?

Are you not still covered by any waranty for all the new stuff you fitted? It was only May.
 
Do the heads yourself. I would say that though, to try and legitimise my own stubborness!

I'd even think about Helicoiling all the block threads. Doing it yourself might only take a day, and at least you'd know the threads were strong.

4 in 4 years across 2 engines has go to be either unlucky, or something else is wrong no?

Are you not still covered by any waranty for all the new stuff you fitted? It was only May.

I'm feeling i've nothing to lose by stripping it down to at least see whats going on. Just been reading up on issues with thin walls around the bolt holes in the block & cracking etc so helicoiling does scare me a little.
No warranty i'm afraid. I bought the top hat block, pistons, crank from a guy on the bay who builds them for racing etc. This block was from an unfinished project of his. Everything else i got from Turners as it was a full rebuild job. In hindsight a short engine from Turners would have been a better option but you live & learn.
 
At least if they've been off recently, the fastenings won't be rusted and you should be able to take an internal look pretty easilly. I spent 2 days this last weekend just trying to undo stuff on mine.
 
At least if they've been off recently, the fastenings won't be rusted and you should be able to take an internal look pretty easilly. I spent 2 days this last weekend just trying to undo stuff on mine.
Hope all goes well with yours. May be asking some advice soon enough! Think i might get myself a torque wrench & have a go.;)
 
Martyn am I right in remembering you still have the block that you originally took out of it.If so how about send that block away for top hatting take the engine out that is in there now and swap everything out (crank ,pistons, etc) and put it in the new top hat block. Long process but not as expensive or heart breaking as the alternatives.
 
Odd that MrGorsky's was blowing in almost exactly the same place. The head bolts came out a lot easier in the middle than at each end as well. I found that I little odd at the time and must say it worries me a bit when we're planning to put a fair amount of torque on them to get them done up again. Even more worried now after hearing Martyn's story.
 
Martyn am I right in remembering you still have the block that you originally took out of it.If so how about send that block away for top hatting take the engine out that is in there now and swap everything out (crank ,pistons, etc) and put it in the new top hat block. Long process but not as expensive or heart breaking as the alternatives.
Yep, still have my old block, i just haven't the inclination to go through yet another engine rebuild unfortunately. Plus, i still have 2 HG's fail on middle cylinders on that block :(
 
Odd that MrGorsky's was blowing in almost exactly the same place. The head bolts came out a lot easier in the middle than at each end as well. I found that I little odd at the time and must say it worries me a bit when we're planning to put a fair amount of torque on them to get them done up again. Even more worried now after hearing Martyn's story.
My mechanic has always ranted about how random the stretch bolt torques are. Maybe ARP studs are the way to go?
 
You will be needing a long breaker bar to get them off then the torque wrench to get them started the the breaker bar for the final x 2 90 degree turns
Cheers Dave, any recommendations for a torque wrench? Still need to go through my tools (shed got broken into late last year & whilst i replaced most things via insurance, i'm still discovering tools that have gone).
 
I'll have a few reasonably specialist tools you can borrow too if you do it.

I've just bought a good quality 5/8 impact socket, and a torque dial guage for starters. I'll post them up if you want.

A 4 foot breaker bar is a must, I'd consider renting a torque wrench if you haven't got one. You need a few imperial sockets too. Everything from the exhaust manifolds back to the engine is imperial. Everything forward is metric.

I got the HG kit from Turners. And a box of stretch bolts from them too. All in it was £115 or thereabouts.
 
any decent torque wrench should do a 4 ft breaker bar would be good i had to use a bit of scaffold pole on the end of my 2 ft bar impact sockets are much stronger iv got a decent set here i use rather than my standard sockets
 
I'll have a few reasonably specialist tools you can borrow too if you do it.

I've just bought a good quality 5/8 impact socket, and a torque dial guage for starters. I'll post them up if you want.

A 4 foot breaker bar is a must, I'd consider renting a torque wrench if you haven't got one. You need a few imperial sockets too. Everything from the exhaust manifolds back to the engine is imperial. Everything forward is metric.

I got the HG kit from Turners. And a box of stretch bolts from them too. All in it was £115 or thereabouts.

Cheers fella, i'll bear that in mind. Just pricing up the parts from Turners. They do a full top end kit i,m looking at :

http://www.turnerengineering.co.uk/acatalog/Gaskets---Seals.html

Also, guess i need the sealing compound (Dirco S) for the inlet manifold gasket?
Will check my sockets tomorrow.
Was looking at the LPG pipes etc...that's going to be fun!
 
My mechanic has always ranted about how random the stretch bolt torques are. Maybe ARP studs are the way to go?
I just posted my misgivings about stretch bolts on Mr gorskys thread. Breaker bar on an ali block wtf. I've got ARP on mine, 70lbft, you could just about pull that with a combi spanner.
We use norbar torque wrenches at work
 
any decent torque wrench should do a 4 ft breaker bar would be good i had to use a bit of scaffold pole on the end of my 2 ft bar impact sockets are much stronger iv got a decent set here i use rather than my standard sockets
Cheers Dave,
Ive got a 2 ft good quality bar (got it to remove a rather stubborn transfer box filler plug).
 
Point taken Martyn was just a thought to save a decent p38. If all else fails you could get a bare block from turners and build it up as a last resort.
 
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