Mopar Muscle Association UK

Dave81 wrote:Sorry to see that the engine is constantly showing up new issues.

On the positive side, all the stuff you have found would ony hurt HP......................So when rebuilt and to the right way, you should find your stroker is putting out a load more power!!!!!

Trying to find the positive........

To be honest I could of done without it, but am glad it has shown up now and not further down the line when it could of been too late but on the positive side, I will know the engine inside and out.

Don't know how bad the other pistons are but the one in the picture does not look very useable to me, at least not till the bores and pistons are measured and then measured again once the hone has taken out all the scores from the bores and if they are straight, then see how much PTW clearance you have if your gonna re-use on advice from a good engine builder...DaveB perhaps, he should give you an honest answer!

Les

All pistons the same. But could be in bother measured top of bore with vernier, I know you need to use a proper bore gauge to get a proper reading. I was just checking bore size to get an idea of rings I need, looks like its .60 over dangerous ground.

Not that I know much. But why would a fresh built stroker motor be .60 over on bore size ?
Surely that's a route you take after problems or after a good few miles ?
Sorry if I'm posting crap but I need to learn !

I spoke to Simon who had the Engine built, I needed to ask him how far he had it bored out as my readings were way over what it should of been. Stock 340 bore is 4.040" Stroker with 30thou over bore should be 4.070" I was reading around 4.090 so I asked Simon what he had done, He said. When he pulled the engine it was already +30thou with scored bores, the engineering firm said +40 will probably not cut the scoring out so they went for +60thou if his memory is correct but +90 odd thou reading would make it + 50 over the stock 4.040"

Your not having much luck with that lump mate.
Stick at it. If you need a hand give me a shout.

Good luck with this Carl and you willl hopefully have a solid motor when done. Like you say, you are getting to know her well and very valuable experience gained.

I have a daft question....what are the tell tale signs on the piston photos that make you think some overheating has occurred? Im guessing at discolouration but how does overheating result in scoring in the bores?? Excuse my ignorance Carl but think us amateurs are looking to learn from this thread/ build

cheers Steve

Cheers Steve not about to give up yet but I'm now dictated by bore tolerance if the engine has been bored to its max there is nowhere else I can go with it if it needs another rebore due to scoring so it would become a nice coffee table.

Looking at the scoring on the skirt of the piston shows the piston has rubbed along the bore usually get that if the engine has overheated causing the piston to expand

Sorry to see this Carl. Given the possibility of it becoming a 'coffee table' I might be tempted to stick to your guns and clean up as much as,possible and run it.
With that bore now being so close to 'too much' it might not be with throwing wads of cash at it.
Being a stroker it will push the piston harder against the wall if I have my theory right and too much over bore could cause real problems.
Hope it comes together for you.

None of this looks very promising,as said it might be just as well to get it running properly and tear the arse off it until it breaks,there's no more left in the block. Can't remember who built it,but,whoever it was, just make a note never to use him for anything again.

The scoring on the pistons looks like the bore clearance was too tight, I guess it isn't now. See if the block will clean up with a light hone and then check the bore clearance, if it's somewhere near right I'd put it back together, the pistons don't look badly damaged.
Use a good quality billet timing set and you can get a chain tensioner which is worth fitting. Make sure you degree the cam in, it is well worth the time spent to avoid future problems.

I think it is a case of make the best of it as said previously.

Only one thing to add really...I think you can pull ANY engine apart and find fault - however minor, it is a question of degree.

What you need to decide is what is "Good Enough" for your purposes.
You are not out to make monster power.

You may have to put up with Piston slap noise and high oil consumption - or you could buy a replacement block that MAY be OK, new Pistons, bearings, Rings, re-balance, divorce, etc.....

You may need new rings anyway - check ring gaps - and again that could be a case of what is available.

I have an engine where the ring gap is excessive but the bore wear is not, but nobody makes oil rings that are oversize in that configuration.
In my case it is either risk oil blow-by or have a re-bore.

Choices, choices.

All the best with it...

Is resleeving the bores an option??!

Steve wrote:Is resleeving the bores an option??!

£140 per sleeve.
Most Hemi blocks are not worth Lining at that price........

Blimey Pete...see what you mean...that is pricey!!