Monoposto Racing Forum

Last weekend a little trip into the gravel punched a hole in the side pod and a stray stone must have whipped off the water pump belt and the cylinder head cooked. I borrowed a compression tester from Doug, which helped to identify number two and three cylinder to be low, although the water squirting out of the spark plug holes did provide a more graphical representation of the issue and we were forced to go home early.

Now, I have stripped the cylinder head. Using a straight edge and a 0.15mm feeler gauge I can get it under the straight edge in the centre (between 2 & 3 cylinders) proving it is warped in the centre!

I rang Scholar and got the sucking plumber routine. "Well sir, its best to send us the whole engine because you've probably melted the Moly out of the piston rings and probably the block is shot too." As far as I can tell the block is fine. (Can't get a feeler gauge under the straight edge anywhere). There is a temp strip on the side of the block which has only reads 110degC, so I think the block is perfectly fine.

My question is; should I be worried about the block? and where is the best place to send the head to be skimmed? I was intending to send it to Scholar but I've spoken to a few of people in the past couple of years who have had bad experiences with Scholar and after speaking with them today I've got my reservations.

Any ideas would be well received.

Having run Hillman Imps for a long time, blown head gaskets and warped heads are almost an annual occurance. A good snarl up on the M25 is normally enough to warp the ally head. Never had a problem with the block though, a skim was enough to fix the problem.

No idea where to get the head skimmed, but if you are pushed for time and want to do the Brands Indy, I have a spare you could borrow for the race.

Thanks for the kind offer Pete, unfortunately due to work commitments I'm not able to race again until the Oulton Park round in July. So plenty of time, provided I can get someone to do the machining.

I've also got tiny marks on the exhaust cam shaft journal bearings where it looks like its rubbed slightly. Its only slight discolouration and the inside of the corresponding caps appear to be unmarked. Is this a serious problem?

Try Ewen Sergison at Avit motorsport, he'll sort it for you, he visits the forum and also on facebook.

James

I am probably heading over to Ewan's with his mini gearbox next weekend, maybe a bit later. If you want I can drop by yours and pick up any parts you want dropping over there.

I can skim heads too if it helps. Usually only an hour or two, but appreciate I'm not exactly just up the road from you (near Snett).

My friend Roger DOnnan has a brand new Zetec head unused. He bought a new engine from Raceline but only wanted the bottom half as he has some special Carlos Fandango head on his motor . He is looking to sell it for a reasonable (cheap) offer. Pm me and I'll put you in touch if you want.

Before you part with too much cash, Roger bought a complete engine from Raceline for £500.

James

my pennyworth

1. Unlikely you have any block damage
2. Any engine machine shop will skim the head. Look on Federation of Engine Remanufacturers website if you can't find one readily in your locality - they will be doing em day in day out
3 ..or...perhaps speak to Jonathan Weston-Taylor 01302 710661 Stanwood Engineering in Doncaster as he runs a machine shop & has raced Zetec engined cars for ages. Doncaster is not a million miles from Grantham is it? They are both on the great Axis of Misery
4...or...you could buy a 'ready skimmed' Zetec head from me @ £40 + £14 carriage (though i've never run it but it all looks ok)

..and finally

when you skim a head you increase compression (not that anyone in Mono ever seems bothered) but you might want to
speak to the 'powers that be' if you are intending to win - just so you don't fall foul of regulations. I suspect technically you are supposed to remove an equivalent amount of material from the combustions chambers.....but i have me doubts if people ever
do this

..and even more finally

as water is likely to have got into the oil you might want to be quite sure you get it all out before Brands disappointment gives rise to Oulton disaster

Dermot's post is, as ever, rich in good advice.

However when he says "when you skim a head you increase compression (not that anyone in Mono ever seems bothered) but you might want to speak to the 'powers that be' if you are intending to win - just so you don't fall foul of regulations. I suspect technically you are supposed to remove an equivalent amount of material from the combustions chambers.....but i have me doubts if people ever do this" I need to spring into action with a response

James car ran at Brands in Mono Ztec, so FF1800 engine regs apply. As I understand it these do permit skimming the head to correct its flatness, but this must not be at the expense of infringing the compression ratio requirements which specify a minimum cylinder head volume. I think it's essential to read and apply the FF1800 regs in this regard to ensure that the engine remains eligible. I can supply a copy by email, although I think they are downloadable from the Club's website.

And...the Club does check engines. The last person to be be excluded from from the Championship as a result of an engine check was at the end of 2011...due to a technical cylinder head infringement....

Rgds

Simon Davey

Well sprung Mr D. Good to know such a careful eye is kept on these things

I happily withdraw any suggestion that the Mono competitors might perhaps have a cavalier attitude
to such things. I know you all have 50ml burettes in the garage.
(only £15,00 + £5.00 carriage from reputable suppliers)

& when not using 'em to measure cyl head volumes they come in ever so handy in the kitchen
when preparing all those Heston Blumenthal recipes

I never got my snails from Dermot...

When not in engineering use my burette is used to make the perfect Mojito. Just make sure the Rum is at minus 10 degrees before measuring and get it done quick else it warms up too much

Oh and dont put the sugar or mint in the burette as its a fiddle to push out again with tig wire...

Regards

Jon

PS. Zetec blocks are solid as - duratecs warp - zetecs will take a right hammering - just get the head done.