Rattle from engine

plastic orange · Post by **plastic orange** » Thu Feb 15, 2007 5:29 pm

Got it started - still rough, but pulled the 'new plugs' and 3 of them had the electrode bent closed - obviously hit by valves. Replaced them and it still doesn't run smoothly. Ebay beckons.

Pete

sidecar · Post by **sidecar** » Thu Feb 15, 2007 6:29 pm

Hi Pete

I don't think the valves can hit the plugs no matter what shims are fitted,
not unless the valves are already bent to buxxery.

The pistons maybe able to hit the plugs but a hxll of alot must have been skimmed of the heads. Even then I'm not sure, as the pistons are basically concave and the plugs don't point straight down.

Maybe the valves or the pistons can hit the plugs if you've fitting the wrong of reach plugs. (If the valves hit the plugs then it may have bent the valves).

If the pistons have hit the plugs and they are the correct reach then they have probably hit the valves too.

It may not be too bad, I reckon you've got the wrong plugs fitted and hopefully its the pistons that have it them not the valves.

Pete

plastic orange · Post by **plastic orange** » Thu Feb 15, 2007 7:49 pm

Yes, it's a bit of a mystery - plugs are the normal long reach ones (p6 heads had short ones), and the engine is the p6 with 9.25 comp ratio - dished pistons, so I wouldn't have thought they'd touch. I am starting to think that the heads have been well skimmed before I got them. When I put replacement plugs in they haven't been touched by anything so far.
I'll investigate further tomorrow.

Cheers

Pete

sidecar · Post by **sidecar** » Thu Feb 15, 2007 8:18 pm

Good luck with it, I hope you get it sorted.

ihatesissycars · Post by **ihatesissycars** » Thu Feb 15, 2007 8:22 pm

Just because the plugs are new doesn't mean you should assume they're gapped properly. You should always check as i'vve bought some before only to find they had been dropped which closed the gap.

plastic orange · Post by **plastic orange** » Fri Feb 16, 2007 11:41 am

Did a compression test today - not good news - 3 have nothing, so I'm off to strip it down - hopefully won't be too much damage (there will be knowing my luck). I really should have looked more closely at the heads to see how much had been skimmed (reminder to self - don't buy off Ebay).
May be cheaper to buy a runner, although I have a complete short motor out of an SD1, plus a set of heads from a different one, but of unknown history.
Keep you posted.

Pete

Post by **katanaman** » Fri Feb 16, 2007 3:18 pm

ouch I hope this isn't it but sounds like bent valves or with the plug damage broken valves and the head is hitting the plug

sidecar · Post by **sidecar** » Fri Feb 16, 2007 5:33 pm

Sorry to hear that mate.

Maybe the valves are just a bit bent hence no compression which would be better than the heads dropping off the valves which would also mean no compression plus knackered pistons and head.

It would be worth getting a burette and some perspex so that you can work out your compression ratio.

Regards,

Pete

plastic orange · Post by **plastic orange** » Fri Feb 16, 2007 5:37 pm

No, much worse - engine scrap - check out the pics. Some pistons seem to have come into contact with the head, damaging both (only taken 1 head off so far - headers are a swine to get off). Valves however are fine, so can at least use them again because they were new. When I measured depth of head (to see how much was skimmed off) it seemed very close to original heads I have, but the combustion chamber is a lot smaller (don't know how I didn't notice that, but suppose I just thought Vitesse heads were like that).
So, it's either buy a good replacement motor, or rebuild an SD1 motor and heads I have lying around. I also checked the cam and followers again, and they seem in really good order.

The pics:

Before I started

One off

No 1 N/S

No 4 N/S

No 2 N/S - undamaged

Pistons

No 1 N/S

Head

I really don't know why 2 are damaged, but not the others. I think 1 on the other bank will be the same.

Pete (pissed off)

Post by **katanaman** » Fri Feb 16, 2007 8:10 pm

That doesn't look like contact damage to be it looks like its melted. No way can the pistons hit the heads so long as the block isn't skimmed and looking at your engine number it isn't. Unless of course the big ends are completely gone.
I guess its all academic anyway as like you say there is a lot of damage there.
Commiserations M8 its never good to see stuff like that.

plastic orange · Post by **plastic orange** » Fri Feb 16, 2007 8:16 pm

I only drove the car about 1 mile on the road, and it was only ticking over in my drive to fully warm it up other than that. The plugs for these cylinders had their electrodes closed flat as well.
Engine ran good and strong prior to putting these heads on, with no rattles and reasonable oil pressure - still ok even though now damaged.
I think that the block had probably been skimmed, hence the composite gaskets I found when i swapped heads originally.
Are these small combustion chamber heads from a Vittese?

Pete

softdash3.9 · Post by **softdash3.9** » Fri Feb 16, 2007 8:36 pm

Sorry to hear of your engine failure, nothing worse a real bummer engine looked a nice set up in the morris

If you are stuck or looking for another running engine I have a 3.5 Vitesse spec long engine available, may split into a short block.

It was removed from a twin plenum, and in fact ran smoother than the engine I rebuilt for my own car

have a short video clip somewhere if interested

The only down side is that it was painted blue by the previous owner and it's peeling off

plastic orange · Post by **plastic orange** » Fri Feb 16, 2007 8:58 pm

pm sent Royston.

Pete

JC. · Post by **JC.** » Sat Feb 17, 2007 8:02 pm

Im not too far off putting some Sd1 heads on my P6 engine.... am worried now!

What would cause the alloy to melt? CR far too high perhaspse?

adamnreeves · Post by **adamnreeves** » Sat Feb 17, 2007 9:01 pm

I am no expert but when I saw the heads I thought perhaps changing composite gaskets for tins and smaller combustion chamber leading to too high compression ratio leading to detenation. If it was ran any longer I guess it would burn a hole thru the piston crown.

JC. wrote:Im not too far off putting some Sd1 heads on my P6 engine.... am worried now!

What would cause the alloy to melt? CR far too high perhaspse?