Overfueling -> Bore Wash -> Blow By -> Crankcase Pressurisati

[veloce200 3]

A peaky cam is going to require more fuel at high rpm than a milder cam, that's just obvious and I can't believe the fuel map wasn't changed to suit.

 

not necessarily. depends what you mean by peaky. the 343 cam has later inlet closing which has reduced dynamic compression in Sean's engine. Also Puma did painstakingly design the engine engine around the 340 so who's to say the 343 would definitely need more fuel. All the indications are the engine is running very rich. I didn't know til I read this thread that the car had not had AFR checked on the RRoad 2nd time round and as you say it seems like an oversight.

 

There's no way I'd let anyone who thinks that crankcase pressure and oil pressure are related even touch my car...

 

I may be being paranoid here but it seems you might be referring to me here from another post? If so I didn't say the two were related... but if you think about it they are - without oil pressure you can't run the engine so you can't have crankcase pressure..

[Alastairh 47]

I think Batfink hit the nail on the head.

 

Out of your list of 6/7 people, pick who you can trust. Get one that you get on with, be PATIENT and let just them take it appart and see from there.

 

Far too many ifs and buts...

[veloce200 3]

was it run in on synthetic oil? many believe this simply doesn't enable a proper ring seal to develop.

[smckeown 1]

Out of your list of 6/7 people, pick who you can trust. Get one that you get on with, be PATIENT and let just them take it appart and see from there.

 

Again this is an exaduration. You chaps aree wandering from reality here..

 

I agree you should choose one person and stick with him, that was how I started out, but life doesnt work out like that sometimes. The potential to fall out with your engine builder is in direct proportion to how long he takes to build it

[Batfink 201]

talk about wondering offtopic. Due to the circumstances at the time the engine has been touched by many hands. But that does not mean it should go wrong.

 

Its pointless arguing over the past and my point was to get it to someone and get it tested as internet advice is never specific to the real engine itself. To work out the issue it needs a physical examination.

 

Good luck with Des. I doubt this thread can really go on until we hear some news from them!

[smckeown 1]

was it run in on synthetic oil? many believe this simply doesn't enable a proper ring seal to develop.

 

no mineral, all run in as per PRs advice/procedure.

[smckeown 1]

just spoke to mikanics.

 

He uses a motec wideband and therefore is confident the AFR would have been fine during mapping. Even though he hasn't altered the fueling the cam was changed a lot during the mapping.

 

His advise was to chech fuel pressure still the same (FSE hasn't changed since mapping) and water temp sensor still working.

 

This just odd that the oil was changed just before it was mapped a 2nd time and the next day at anglesey the car suffered bogging down and oil leaks. This i believe was the start of the crankcase pressure. Few days later oil changed and shed loads of fuel in the sump.

 

I'll check out the FSE boost valve, as I know this was running at dead onn 4bar as the gauge in ht eengine bay tell me. I can check out water temp also, as well as the injector test

[veloce200 3]

no mineral, all run in as per PRs advice/procedure.

 

when you look at the breathers on these cars they don't appear to offer much of a path for crankcase pressure to escape. Specifically the cam cover breather in your pic looks like to goes back to the block? I've not got my pug with me today to check the std layout (perhaps someone can check theirs?). Either way every part of your engine has been modified except the breathers. More blowby is a natural product of your high compression engine. IMO there is nothing intrinsically wrong with it. if it were me I certainly wouldn't be looking to rebuild. the cam cover breather could be enlarged and vented to atmosphere to test the theory. the other breather ways could also be enlarged (your catch tank inlet and outlet are very small). This won't cost much and it'll either work or not.

[smckeown 1]

How I wish I would have originally bought one of these..just arrived:

 

[TB_205GTI 1]

How come you changed the cam for a "hotter" one?

 

As I see it the engine would be _really_ competitive on the track, but not impress with the numbers down at the pub.. Thought htere were some dips in the torque curve that should be able to iron out with trumpet sizes and/or mapping again. Why hunt for 10bhp at 7.000 rpm - when you then loose some grunt at 4.500 ?

[max0 5]

was the head reshimmed after the valve spring snappend and the new cam fitted?

 

could this explain the loss of compression?

Edited December 15, 2006 by max0

[smckeown 1]

How come you changed the cam for a "hotter" one?

 

As I see it the engine would be _really_ competitive on the track, but not impress with the numbers down at the pub.. Thought htere were some dips in the torque curve that should be able to iron out with trumpet sizes and/or mapping again. Why hunt for 10bhp at 7.000 rpm - when you then loose some grunt at 4.500 ?

 

It's all been discussed before. I don't choose cams, I was advised to try it to see if that would stop the torque from falling off so quick, while not losing too much torque mid range

[chunkymonkey 0]

this isnt a dig at anybody just something i find true to life.

 

what ever you have or have done. you always want more from the engine,brakes suspension etc.i was like that with my last 205gti.that ended up going bang too.

 

then it was the mini cooper (the real one not the makeup bag on wheels)

i had that done at minisport it didnt go bang and was very good fun!

 

then i got the clio182sport trophy yet i still wanted more! fantastic car but their is very little envolvement from the driver.you could turn in to a corner and if the car trys to breakaway the traction control beats you to correct the car.to me thats just boring really i wanted back the 205gti.the real feeling of driver involvement.raw.rough.and exciting.i bought a clean standard example (had a few teething problems though)

 

yet again im the in the queue.

im asking the question............please sir can i have some more!!!!!! is it worth the heart ache?

ohh yes!!!!

 

http://s122.photobucket.com/albums/o255/garylegname/

cheers gaz

[smckeown 1]

was the head reshimmed after the valve spring snappend and the new cam fitted?

 

The work was done by QEP..enough said

[SPGTi 2]

I only live a few miles from where DES take their cars for mapping and know the owner pretty well. Let me know what day it is being mapped and I will have a wander down.

Would like to see the car as it looks good in all the photos.

 

Steve

[Robsbc 0 1 Cars]

4 It broke down at Matt's so pretty obvious he might as wel fit it, or do you think oi should have removed the lump and sent it to the builder who by that time wouldnt even accept my emails ?

 

Looking back through the posts DB offered to look at your engine on this forum after your engine breakdown why didn't you take it up? And don't say he wouldnt even accept your emails as that's a cop out...His words were for Matt @ QEP to send the head down to him unassembled.

Edited December 16, 2006 by Robsbc

[smckeown 1]

Looking back through the posts DB offered to look at your engine on this forum after your engine breakdown why didn't you take it up? And don't say he wouldnt even accept your emails as that's a cop out...His words were for Matt @ QEP to send the head down to him unassembled.

 

I dont have to justiify my decisions to you or anyone else. Do you go through all the posts on here that are 6 months old and questions their decisions ?

[Robsbc 0 1 Cars]

I dont have to justiify my decisions to you or anyone else. Do you go through all the posts on here that are 6 months old and questions their decisions ?

 

yES

[Pugnut 9 1 Cars]

borewash goes hand in hand with bad pre ignition doesn't it? Then if it's been mapped with over retarded ignition then it wont rev well at high rpm right?

 

stupid question due to experienced engine builders, but if you have polished inlets on youre head then the fuel vapour can condensate on the walls and run into the cylinders.

 

just trying to throw a few things in that hasn't been mentioned.

 

my 1.6 (ok it was standard though) lost its ability on 2 occasions to free rev well above 4k . 1) after 2 head skims the CR was way to high for the engine . thick gasket sorted that. 2) the distibutor was shot(irrelevant in you're case)

 

cheers , Al

[smckeown 1]

well top marks to des-developments. He told me what he thought it was based on the info I posted here, and after dismantling and thorough review he was right. It's absolutely buggered. Snapped ring, 4 liners nackered, 4 bearings nackered. Just as well I decided just before xmas to completely re-do the build. All I wil lsay is that various (ie more than 1) reasons are said to have caused the catastrophic failure. The new oversized liners are finaly close to being delivered so the build can start. Lots of goodies going in to this build

[Pugnut 9 1 Cars]

sorry guys , but i have detatched the offending posts to try and stop it turning into a bun fight .

 

please contact admin/moderators if you have a problem with this .

 

Regards, Al

[Batfink 201]

So what are the issues that cause an engine to completely destroy itself in this way? Sounds to me with one ring gone, petrol would have been able to get into the oil, then without lubrication all the other liners cracked and the bearings would naturally be shot?

 

Is this just a case of pushing near standard internals too far, when really you should save up for a proper track engine so save time, hassle and pain from overstressed parts? I have a near standard Mi16 that will have non standard fueling and ancillaries so am very interested in what can go wrong.

 

Hope everyone can bite their tongue so we can have a proper discussion

[taylorspug 7]

Is this just a case of pushing near standard internals too far, when really you should save up for a proper track engine so save time, hassle and pain from overstressed parts? I have a near standard Mi16 that will have non standard fueling and ancillaries so am very interested in what can go wrong.

 

Hope everyone can bite their tongue so we can have a proper discussion

 

Id also be interested from this POV aswell.