Right done a whole 60 miles on engine rebuild, yesterday morning the water started to pressurise, forcing itself out of the header tank. No pressurised hoses. !0 miles latter steam galore out of exhaust, resulting in no compression in any cylinder! oh mother feck
Heres the gasket
The head was skimmed and pressure tested prior to fitting and was 72.5mm high,
The carb has a standard 120 main jet,.90 air corrector,standard 1st stage & the 2nd stage has a 1.4. The turbo is a t25 and thye actuator is set at 22psi. This car has by no means been ragged, and i have tried to run of boost as much as possible. I was going to be usinga wideband and have a big jim downpipe with bung , which i had to take of as it wont mate to my magnex system, hence why it has been running without knowing what its fueling like, Also dont know condition of regulator or renix unit 208 that has a knock sensor attached to it,(not sure if this is possible).
some more pics to show the egging compared to liners
When the head came off, the 2 liners furthest away from the flywheel were full of coolant, so was exhaust manifold. When i dropped the oil , about a litre of coolant flooded out firstPistons and liners still look fine, cant see any cracking unless they are cracked below the piston tops.
Pics of the head which is still straight, and liners, pistons and block cleaned up.
Would like some opnions please, were to go from here, whether people think this is all fuel related, thing is ive never seen a gasket go before on all cylinders.
If the head is 72.5 mm, i would guess at 22psi thats very high compression. Also the fire rings are all oval. It doesn't look like its fitted too good. Also check liner height. Protrusion should step down from either end.
Any pitting on the pistons etc?
check the aei vac capsule is ok. then fit two headgsakets.
Agree with Matt, those fire rings look very oval, id say the gasket has been fitted out of line to the pots. Also 72.5mm is 0.5mm below minumum you'd want for a gtt head. Get yerself another head mate
lower the comp as stated by fitting 2 headgaskets or either get the crowns machined off the pistons or have a section of the squish area machined from the head.
Pistons and valves look perfect still. When I did look at the gasket and a few other people looked at it, we did notice that the back of it doesn't have as much indentation as the front, the back of the block has now been wet and dried a bit as it looked a liitle rough/rusty. The bolts were done up to 80nm last time. Is running two headgaskets reliable ? Sounds like a quick fix. Thinking of running standish boost amounts 14psi untill I can get a decent head, gonna put on a renix 09 unit that I have and plumb in a boost gauge into the fuel line to see what fuel pressure I am getting. It should be 4 psi more than boost pressure at all time shouldn't it? Any other thoughts? Does this sound ok for a few hundred miles as I need to get it mobile as were I'm keeping it is becoming a building site and I need to move it. Anyone with a decent head for sale for a decent price? Pretty please.
are you sure that the bolts were clamping the head, and not bottoming out in the threads? Wind them into the block by hand and see how much they stick out.
Feck, you may have made a valid Point there andrew. Wound them into the block yesterday and remember about half a cm of thread being visible. Didn't think much about it at the time, and have put a new gasket back on about half an hour ago
Originally Posted by TrixNFlix
Feck, you may have made a valid Point there andrew. Wound them into the block yesterday and remember about half a cm of thread being visible. Didn't think much about it at the time, and have put a new gasket back on about half an hour ago
also are you putting the washers on the 6 inner bolts
Yep Richie those nice big fat washers are all present
I dont run 22 psi when Im speed eventing, IMO thats a crazy amount of boost for an engine you've just built with unknown fueling.
Cheers russel for your constructive comment . It never went past 3 thousand revolutions so never got anywhere near 22 psi, just the actuator is set up at 22psi not by me , bought it like that so am assuming this is what the turbo is good for. Sorry If I sound defensive but am feeling pretty low about this car.
i remember buying a headgasket that was ovaled like yours so i got another. cant remember wheR it was from.
Like matt says, you won't run 22psi on a 72.5mm head, that's asking for trouble !! it'll have detonated a lot. look at the fire rings for little "dings" and dents.
22psi at carb top. Is that about 19 at manifold. When I built my engine I asked the question will 72.5 be ok and everyone seemed to think it was borderline but ok. Losing the will to live now. Might just split it down and move on to pastures new.
I've felt like that a few times but just forget about it for a couple of weeks then see how you feel
You've only got one head to worry about
everytime i have a problem with mine i convince myself its goin.....I've felt like that a few times but just forget about it for a couple of weeks then see how you feel
You've only got one head to worry aboutthen i come2 my senses calm down crack a beer and come up with a plan of action 2 fix her
Cheers for the love clee, needed it! Been 9 months of hell now, the mrs only makes things worse, she hates it with a passion, to the point if she was alone with it I reckon she would torch it! In answer to scoff the rings have been crushed were it has blown through. Is this det? Never heard any marble****ting metal type noises.
Cheers blick
Get another head whacked on that's a decent height, turn the boost down until you get the fuelling set up, jobs a gooden.
only the other day when my headgasket went on route 2 the fcs i was on pistonheads lookin in2 the 172`s....Cheers blick
Even at 19psi 72.5mm is a no go mate. Find yourself a 73.5mm head and you'll be fine.
Just out of curiousity what would the compression ratio be roughly on an engine which ran standrad top piston's and a 72.5 head.
trust me i feel the same about mine too mate, mines a freshly built engine that i've done about 200 miles on and shes overheating alot so redone my headgasket, put it back together and the rocker arm pulled the threads out the head and were banging against the valves. After abit of engineering and modification today shes back together but still getting incredibly hot...........so i do know how you feel mate, but as all the others say you just have to walk away, chill out, have a beer and go back to it later once you're chilled
Cheers furiokid, feeling a bit better now. Just gotta keep cracking on with it , one day all will be well.
two headgaskets will be fine. - it gets blasted as being 'bodgy', but it works and i've seen 2 cars that have been given 22psi on double gaskets, and the gaskets lasted longer than the bottom ends did.
Thanks for the info sparkie, if I can't get hold of a decent head the 2 gasket Method will be the Road I go down.
no worriesCheers furiokid, feeling a bit better now. Just gotta keep cracking on with it , one day all will be well.
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Hi Trix, I'm not familiar with the R5 hardware; your photos caught my eye. Are those exhaust valves std OE or Rimflow / equivalent design valves? Wondered if they had been recessed to reduce weight / heat retention etc?
Oiii Faulks !!!
Stop looking at 5 head and get those 2 heads finished
I'm rescheduling the pull till after National Day now ...............................................
Hi Trix, I'm not familiar with the R5 hardware; your photos caught my eye. Are those exhaust valves std OE or Rimflow / equivalent design valves? Wondered if they had been recessed to reduce weight / heat retention etc?[/QUOTE]
hi mr fauks. As far as I know everything on the head is oe spec apart from the compression now as the standard heads are 73.5mm in height and this is 72.5mm. That said I havn't any knowledge to know exactly what's standard or not as this is my first engine build, and have no other experience other than working with this car .Regards andy
Dont forget to check that aei out and vac line as said...
Yep cheers rob have done. Changed the renix unit too from 208 to 209 and am thinking I should get rid of the dump valve just to make sure.
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