Another engine ???

[rwdstag]

I have just taken the engine apart After the water pump sized and shredded the Jack shaft also propelled it self up into the water pump cover killing the pump and cover
number 7 cylinder has had water in it which has left pitting
the engine has been re bored to +40 so if all the rest measure up ok it will need lining
number 2 piston has score marks and kinked oil ring BUT no marks on the bore
RH cylinder head is in great shape and looks like it's never been skimmed
LH cylinder head is the complete opposite and looks like I may get away with one more skim
so my question is another block and re use my plus 40 Pistons or line all the bad cylinders and get new rings .I plan on doing a stagdad Essex water pump so the Jack shaft and water pump cover will be ok
Any advice would be FAD
TA Mucho
Rich


s

[Munter]

Hi Rich, your probably going to tell me to go fourth and multiply, but in your case and as you seem to know your stuff, l’d be thinking Ford 302 crate motor, about the same weight and size of the Triumph engine but 1 1/2 litre larger and a shedload more torque, and you’’d still get that nice V8 burble only a bit louder.

[rwdstag]

Made me laugh and sort of tempting but not on this car

[flying farmer]

The current engine I am working on had two badly corroded cylinders that needed liners even after boring from +20 to +40. I was fortunate in that it had been previously linered and it was possible to cut the old liners out and press new ones in which reduced the machining cost considerably.
It is really a matter of balancing the costs of reboring another second hand block and relining the one you have got, second hand bare blocks used to be really cheap a few years ago but most Stag stuff has got considerably more expensive recently.
I once got hold of a cheap rebored block to use my high compression +20 pistons rather than liner two corroded bores, then ended up doing the liners anyway a few years later for another engine build as it was cheaper than a full rebore on the worn block that I was working on.
Neil

[rwdstag]

Is the number 2 scored piston an issue if I put new rings in once honed and with in tolerances??
i really want to keep the original engine but not at all costs
again all advice welcome
cheers
Rich

[edd]

I like the description of your problem. To often blame is put on the shaft it self not the pump seizing causing extra friction which leads to failure.
I'm so glad I converted mine to the stag dad pump.

[Ian P]

I like the description of your problem. To often blame is put on the shaft it self not the pump seizing causing extra friction which leads to failure.
I'm so glad I converted mine to the stag dad pump.

+1 Took Edds advice when restoring my stag and not looked back

[flying farmer]

Is the number 2 scored piston an issue if I put new rings in once honed and with in tolerances??
i really want to keep the original engine but not at all costs
again all advice welcome
cheers
Rich

Rather depends on how badly scored it is. Is it a few deep scores which don't really affect the shape of the piston, or is it a large area that has removed several thou of material?

One engine I rebuilt a few years ago had quite a lot of scuffing on the skirt of no8 piston. It looked worse than it actually measured, and has not given any problems since the rebuild quite a few years ago.

Neil

[rwdstag]

[flying farmer]

At least you were lucky enough to have the pin shear. When my jackshaft and pump failed it snapped the timing chain and bent several valves and broke some valve guides for good measure

[Guest]

When my jackshaft and pump failed it snapped the timing chain and bent several valves and broke some valve guides for good measure

You were lucky.
I bought a 16V Dolomite which some Froggy numpty had just messed around & failed to shim the pump,- (Duhh.....they thought the shims were just gaskets!!).

The gears were so tightly in mesh they went blue, followed by seizure of the jackshaft in the block, which then tore the front end of the camshaft off, ripped the entire set of duplex timing gears off tensioners inc the chain and dumped the lot of bent & smashed fragments down the front timing cover.

When I took the thing to bits, I did finally manage to extract the jackshaft, and polish the damage out of the front journal, by some miracle.
None of the 16 valves touched pistons, but that low mileage French car was out for the count.

[rwdstag]

I’m taking all the parts to the machine shop tomorrow
will let you know how I get on
thank all
Rich

[rwdstag]

Hmm not good news
every bore is worn badly so not hone able
so do I get another block and bore for £200 and get that bored out
buy new pistons etc or line every bore @ £1000 odd with machining and liner ?
on the plus side the heads seam salvageable
if I get another engine then should I insist that it comes with the Jack shaft or will the one I have marry up ok ??????
If not then what are the options
again thanks for all the advice /help etc
Rich

[rwdstag]

I didn’t mean block and bore just the block for £200 then the machining costs to bore out to plus what ever
Rich

[flying farmer]

Probably worth looking for a second hand block if it is going to cost £1000 to get your old one fitted with liners. IIRC a straight rebore on my last block was 280 +VAT. If you do manage to source a block just make sure it doesn't have corrosion pitted bores that will need liners anyway.
Neil