Why does my V8 smoke heavily ??

[Boothy]

I rebuilt the Challenge machines V8 a couple of years ago now, rebored +20", rods all checked for cracks and straightness, crank polished it didn't need grinding new shells (Vandervall replacements, can't remember the name Cleve ??) new pump gears and bottom plate Mopar one, full recon on heads including skimming 10 bolt ones, new Piper RP4? cam and followers plus new bearings, new rocker rails and tappets, all the usual stuff, composite gaskets, neoprene stem seals, everything to give me a nice reliable engine that should do a few years with no drama.

But following a sump full of Kirton water last yearit's never been the same, I got into some seriously deep water doing the Howlin Wolf, the engine never missed a beat because the Megasquirt was superb but when it came out after about 20 minutes of water over the bonnet,the oil pressure had dropped, sump full strauight onto trailer for a good flushing.

But slowly the engine which is only used for comps has been starting to smoke blue'ish and using about half a litre of oil per event. It smokes following a good rev or mostly when it's stood on it's backend facing the clouds and leaning to the drivers side. The plugs foul but I can never say which cylinder its seems common to all.

It runs unbeleviably sweet and has amples of power, is really smooth and starts superb. Compression was about 125psi all plusa out on the starter with the throttle closed and no oil added to the bore, after a squirt a bore it didn't really make alot of difference but all cylinders were very even.

Last bit of the story is last week at the last round or the Howlin Wolf I unbelivably drownded it again and filled the sump again but turned it straight of and was towed back to the trailer, usual flush out and the smoking seemed heavier, so time for a look.

Plenem chamber was a bit oily and wet still but not excessive, trumpets were again slightly oily, bores were all oily to the feel but the pistons are all cleanish not heavilly carboned, the bores all feel smooth but oily and look OK.

Heads stripped and Britpart (I know and I'm sorry) Neoprene valve guide seals don't look brilliant and the guides feels fine. All the inlet ports were free'ish from oil but the exhaust ones were black and oily as were the valves, the inlet valves were spotless.

Took the heads to the reconditioners who cannot see anything immeadiatly wrong which would have caused heavy smoking like I described.

SO million dollar question is "what's wrong with her", pistons are coming up and out tommorow evening so we could be taking bets here.

My guess is a couple of stuck or damaged oil control rings, by the way it's a 3.9 block, it has got very hot in the past before the cooling was sorted and usually has about 30psi oil pressure at tickover when hot, and if it was not for the smoke you would say was a sweet well sorted motor, and no I never saw it breathe, and ALL the gaskets looked fine on their removal. And yes found where the water was getting in through the valley, Sikoflex on the rebuild.

Cheers lads, bit of food for thought isn't it??

[yella 90]

chris, i only had a quick look earlier as i was too busy giggling about your snorkel but at a quick glance there were a few glazed pots

pull the pistions out and have a closer look at the rings

if i have a spare 5 ill come accross and have a look with you

btw, didnt anyone ever teach you to be clean and tidy when you pull engines apart

mud and lifters dont make very good friends

cheers for the hub btw.....i now owe you another one as ive turned this one out and it now fits my toyota axle lovely

dan

[Bull Bar Cowboy]

Well ........... come on Chris FFS get those pistons out.......... I know its cold & wet and you are a northern poof but just get on with it.

I have some ideas but want to see or hear about the pistons / bores first............

Ian

[Boothy]

Hello my old friend, good to hear from you,

Well pistons out, and I can see absolutely nothing wrong, no cracks on the pistonseither top or bottom, nothing in the bore's, a few tiny scratches on the lower skirt but nothing to warrant the smoke, the shells all looked fine, in fact I was quite dissappointed, all rings free to move and intact.

All it can be is knackered Britpart valve guide seals,but I cannot prove it which is even more distressing.

Some come on Ian give me a clue, by the way this thing NEVER used any water at all.

The Northern Poof.

[Hybrid_From_Hell]

Bonjour "Ferr't Man"

Check Rods for alihnment, any twist would see ovality on the bores so

measure them or have checked this would then give blow by on rings

with oval bores, you would,nt ness see by eye

V8s taking drinks are bad news normally

Nige

[Boothy]

Hey up OLD man,

But surely any ovality would have shown up on the compression test with a low reading on said bent rod.

I will check the rings in the bores tommorow afternoon.

[Bull Bar Cowboy]

Check the rods and bores but I think you might find them OK………..

You might have been the victim of coincidence ……….. this may well have manifested itself without a dunking…………

All the inlet ports were free'ish from oil but the exhaust ones were black and oily as were the valves,

That says to me that the exhaust valve guides are very worn……….. or maybe you got the valves mixed up during reassembly (I did once after I knocked them all over the floor !)

The stems of the exhaust valves on the RV8 suffer from bad wear……… the guides wear as well but not as much ……….. I had mine lined bronze lined…………

Are you using the later heads with hooded seals on both inlet and zorst ?

BTW: Go and see Carl for me and stand on his feet with ALL your weight

[carl hurst]

What have i done wrong now

[zoltan]

If it's had a spell of overheatings this could have affected ring tension, if the oil control rings have gone soft that may explain your half litre of oil consumption

[Boothy]

I'll vernier the valves this evening Ian, but I'm inclined to think your right, they are 96 castings 10 hole ones and I've bought home a set of genuine OEM neoprenes.

Yes fitted on both inlet and zorst, bit gutted I've not found anything obvious to put right.

Probably end renewing rings and big end bearings while I'm in bits, but feelit's probably not neccessary.

Cheers lads

[carl hurst]

I'll vernier the valves this evening Ian,

I have a proper internal micrometer if you need to do job a bit more accurate,

Carl.

[Bull Bar Cowboy]

Have you pair of clowns measured the valve stems / guides yet ......... or was Boothy struggling with gimp suit ?

[Boothy]

Well, valves measured OK all about the same and no low or thinner spots, but originally this wasn't a high mileage knacker I rebuilt in the first place,so heads have now been skimmed valves and seats recut and lapped in with diamond paste, re-assembled using OEM neoprene seals and await fitting.

But not being the brightest person in the world, took the bottom end out and stripped for inspection.

Ther crank bearings have signs or slight scratching on them probably from the dirty sump water ingress, will get the crank checked tommorow and re-ground if needed.

Oil pump gears and bottom plate fine no scars or scratches.

Bores beautiful no signs of wear just wants a glaze bust (only just) and back together, broke a water stud off and another requires a helicoil or similar and a good chemical soak.

The dogs danglies duplex timing gears and chains which came from RPi will now fit a mountain bike after less than a couple of hundred hours of use, they are very loose and stretched not very impressed at all.

So question is who is the preffered supplier Real Steel or RPi for new bearings (Michigan) and rings etc bolts and timing gears (which one is recommended), please remember this is not a race car, or is there another supplier who can have my hard earned money.

Loved reading your engine build again Ian, cocky git.

[Bull Bar Cowboy]

Michigan77 / Clevite tri metal mains & big ends from Real Steel...............also a Cloyes true roller chain set from Real Steel, however, you get what you pay for and this set is £108 ........... use it with the zero keyway, forget the 4 degree cam advance or retard, zero is safe !

Did you measure the guides ? ......... dont even think about replacing them it is an absolute barsteward of a job pressing them in (getting the old out is even worse), then you have to ream them to size. I can give the name of a place that will bronze line them..

[Hybrid_From_Hell]

ARP bolts are a Dogs Doodahdays IMHO

Use mains and head sets as a minimum

Nige

[lansalot]

I find a smokey V8 is usually the result of peer pressure - too much hanging around with smokey diesels. Get him into a better crowd !!!

[mobyone]

my first thoughts were oils scavaging rings probably lost there spring or valve stem seals.

heavy smoke says it is burning oil or it is overfueling alot, so it must be coming throught the bores or through the stem seals.or maybe you bent a valve! or damaged the rockers or even the tappet clearence but that would mean taht it would not run sweet like you say.

you have done alot now anyway, so the rings wont be much of a cost, change 'em. but as so much has been done, i rekon the fault wont reappear and you wont know definitely what cured it...