c20xe - lots of problems!!!

[rubachuk]

I bought a Nova with c20xe fitted last week. I got enough off the asking price for me to overlook the problems it has recently had, but I'm finding allsorts I hadn't counted on as I delve deeper.

I knew that before I bought it it had had the porous (cracked) head problem and had had the repair done. Virtually no miles on it since then. The water and oil looked OK when I went to view the car, bit of film on top of water but the guy said he'd flushed it loads and it was left over from the porous head problem. We took the car out, it took a while for it to settle the idle down but it pulled really well and seemed OK. I bought it (obviously) and brought it 200 miles home on a trailer. I've only driven it from the trailer to the garage since.

Now the water is full of oil. The plumbing isn't right so possibly some of this is left over from the porous head problem, or maybe not. The oil seems thin (possibly synthetic stuff) but clean. I did a compression test and found cylinder 4 down at 60psi.

I've taken the head off and taken it be pressure tested, I'm awaiting the results.

Also with the head off I was suprised to see that it appears to exhaust valves have been hitting the pistons because there is clean uncarboned metal in the cut outs on the pistons. However the valves show no signs of having hit the pistons. The head is pretty well skimmed by I phoned Courteney (their Hi-Torq cams) to ask them if there was any possibility of the valves hitting the pistons, they said no chance. I can't really work this one out, any ideas anyone?

The other problem I have is that two of the cylinder head bolt holes have been helicoiled to a bigger thread size than standard, so standard head bolts are no good for these. The guy doing head suggested a local bolt specialist who may be able to sort me out. Is it possible to match the stretch of the bolts even if they're different diameters? Whats the best way around this?

I really don't want to scrap the engine and replace it, although I'm sure some of you will say thats the best thing to do. Sorry about the essay but it's better to give as much detail as I can now than drip feed it later.

Cheers

[bmw156]

if the heaed is knackered, just buy a new head??

if the bottom end is correct.

but, by the sounds of it, you bought it of a pikey lol and i would be checking the lot

[let_nova]

hmm possibly snapped belt at some point.

[rubachuk]

Yup, I've bought a bit of a lemon lol

IF the head is knackered I will buy another.

But if the helicoiled block means thats goosed too then its a full new engine. I need to know if I can get away with what will in effect be mis matched head bolts.

Also struggling to work out why my pistons look like the valves have been hitting and the valves don't :tard:

EDIT - possibly let nova, maybe a tooth or two out on the exhaust pulley?

[let_nova]

no maybe before you got it it snapped a belt therefor the valves hitting the pistons. this would bend the valves so new valves would be fitted.

[philip]

may of had snapped belt before you had it and someones bunged another head on.

if need a re-con head or bottom end sorting let me know, ive tons or parts

[rubachuk]

no maybe before you got it it snapped a belt therefor the valves hitting the pistons. this would bend the valves so new valves would be fitted.
The valves don't look new though, they're full of carbon, just like the pistons except for the pockets on the exhaust side which are shiney bare metal. Just doesn't make sense to me

may of had snapped belt before you had it and someones bunged another head on.

if need a re-con head or bottom end sorting let me know, ive tons or parts
I was planning on getting in touch if this head is fubar'd :thumb:

[rubachuk]

Thoughts on mixing headbolts anyone

[philip]

as in what? you shoulnt have some male torx and some female torx, they should be one or other + im sure the later ones where longer too and known for stripping the threads out of the block

[rubachuk]

The block has had two of the head bolt holes helicoiled to a bigger size so standard headbolts do not fit. The two bolts I took out of these are a bigger diameter than the other 8.

I know its not ideal (far from it!), but if I can source bolts with these threads I presume it'll be OK

[Nobby]

mate **** it off there ennough people on here selling valvers what is it a days job at the most 1 out 1 in no hassle!!

[rubachuk]

Changing an engine seems a bit drastic for the sake of a new/repaired head and sourcing a few different head bolts. Should be the last resort. If it turns out the head is fine and there's a problem with the block then I may have no option I guess

[rubachuk]

Head has got a clean bill of health. Where do I look for my missing compression now? Piston rings?

Rings are supposed to be new with the block rehoned, but given the standard of workmanship so far encountered that isn't very reassuring :(

[tom reid]

You should have done a cyl leak test on the engine prior to stripping, take the valves out of No 4 and check them, they could be bent or have severly worn guides, might even just need lapping in.
I wouldn't scrap the bottom end just for the sake of a couple of bolts, as long as they torque down ok, they'll be fine, are they near to No 4 by the way?
Also, remember that you have to measure the head height versus the head bolt length. they could be too long, if the heads had a lot taken off.

[rubachuk]

Cheers Tom. I got the head back from a head specialist today with a clean bill of health so I'm looking at the block/pistons now. I wish I'd thought to do a leak down test before but I didn't.

The guy in the head shop suggested parrafin in the bores to check the leak rate so I'll try that. Bit of a pikey way of doing it but it won't hurt.

Regarding bolt length, I've noticed the 2 mismatching bolts are approx 10mm longer than the standard bolts so I'll try to source shorter to replace them with. There are no signs on the gasket that they didn't torque down properly before though.

[Lee H]

If two bolts are bigger has the head been redrilled as well so they can fit through?

For the sake of the price of a set of rings is it not worth changing them while the head is off?

[Sloth]

tbh like nobby said why rebuild a dog when there are decent xes about that ou could rebuild instead.

[rubachuk]

Two of the holes in the head have been enlarged to suit.

Set of rings - you mean piston rings? Don't you need go at the pistons from underneath, rehone etc? If it does want new rings and all that malarkey, then I might have to consider another engine although I still see it as a last resort

[Jon_nova1]

I've never tried this before, as i've never had the problem, but wouldn't it be possible to weld the helicoiled bolt holes, drill and tap?

Have you found any other problems?

[philip]

tbh for how much it would cost to have the block welded up, drilled and tapped, you could find a half decent block and buy some headbolts and rings.

tbh. id look at either rebuilding the bottom end...if bores have no lips at top(or very faint) then could get away with a hone and re-ring, sump gasket set and away you go.

or find another motor. do you know if the head shop vacumn tested the ports to see if the valves were sealing?

[rubachuk]

The guy in the head shop vacuum tested the ports while I was there and they were fine. He pressure tested the water/oil ways up to 80psi, as much pressure as he had available, and they were fine too.

I'm not considering welding them up, I've gone about as far as I'm prepared to with this engine. I'll get a new gasket and headbolts and put it all back together, if it works great, if it doesn't then unfortunately I'll give it up as a bad 'un and look around for a good replacement engine rather than spend any more money on it.

BTW, results of pikey paraffin in bores leak test was (with 1/2" paraffin in each cylinder) cylinder no 1 empty in 12 mins, no 4 15 mins (the one with low compression). I got bored with 2 and 3 after half an hour and took 70% of what I put in out.

[Sloth]

id say cyl 1 is a bit unhealthy too....

[MARTIN KELSON]

Hi mate

You could try contacting Fearless (Dave France) from here, he is only in Bacup which aint far from you and see if he has a bottom end or engine lying around.
He works for Vauxhall and has done alot of XE conversions (including mine) so may be able to assist.

Martin

[rubachuk]

Cheers Martin, that's an option for me, along with Philip who has also contributed to this thread.

Sloth - I had no worries about no 1, compression test was on a par with 2 & 3. I'll just see what happens when it's back together. If it's fooked then you and nobby win, new engine time....

[Sloth]

mate, im not trying to win, just advise. ive thrown good after bad with xe's, and the only time theyve been any good is when its been a good engine to start with. i hope its sorted easy for you.