GT mediated Awesomeness

[saintjamesy89]

It must have snapped at starter motor cranking speed, so around 200 rpm? But like you say, that's plenty enough to do damage. And I have been trying, rather in vain, to get it starting with a snapped belt. How does the starter drive the engine, is it via the cambelt, or a different means? If it's via the cambelt then i'm more optimistic that i've not done any further damage whilst turning it over repeatedly.

I'll have to start looking up engine dismantling. The exhaust manifold needs doing anyway and i've always fancied learning more about engine internals etc. I s'pose this is a good an oppertunity than any! (Trying to put a slightly more positive spin on the situation).

Thanks all for your comiserations, just opened a beer and ordered a takeway - feel better already

[Kitch]

If it was cranking normally then the belt was intact at that point. If the belt has snapped, it will just spin the engine at a constant speed with a high pitched whirring. You'll bend valves just by attempting to start it, but probably not much more. Keep an eye out for a good complete used head.

[mat_fenwick]

Bugger. Am I right in thinking it didn't cut out when running? If so it must have snapped during a starting attempt, in which case the engine is only rotating at a fraction of idle speed. I'm surprised it didn't jam whilst cranking, but seeing as I've never attempted to start an engine in that condition I wouldn't know!

If I can make it down there this weekend I'll pop a belt on for you and at least we can then do a compression test. If that's OK then you should be fine. The valves are in line with the pistons rather than at an angle, so less of a tendency to bend - the only time I've seen the results of a snapped belt has been on a diesel (much less valve to piston clearance), which caused the camshaft to break!

EDIT - a couple of posts while I've been writing this but basically saying the same thing!
The starter drives the crank via the flywheel, so the bottom end of the engine will have been rotating but not the camshaft. Some of the valves will have been partly open, and could have contacted pistons. It's quite a distinctive sound when cranking as Kitch says, so likely that you'd have noticed. Is it possible mice could have chewed through it whilst stored?

[saintjamesy89]

Kitch, from your post then it must have snapped today, as when cranking today it was still cranking in the normal way, ie the chug chug sound that healthy cranking engines make. In this case, it hasn't been cranked with a snapped belt, as I heard no unusual noises.

Mat, it's not run since last October and was running very well then, even the autochoke was good! The exhaust manifold was leaking though. I do have a 'new' belt that the car came with, but no water pump or tensioner which i'd like to do eventually. You're very kind Mat, thanks.

[Gary]

As Matt has said I would be tempted to put a belt on it and carry out a compression test before you pull the head off, you may strike lucky and get away with out any valve damage

[Mickey taker]

agree with the above,
had a belt go on my 1.9 petrol ( same engine ?) 405 estate when slowing down for a roundabout , , realized what had happenned so put the clutch down ,turned ignition off and let it roll to a stop.
stuck a new belt on it and she started up straight away and ran fine , put another 12,000 miles on it before selling the car

[Tim Leech]

Bloody hell Tom it's not beena happy BX week all round, big hugs, I hope it's an easy fix.

[MULLEY]

You've got a spare engine now that you've sold WTF Tim, a 2 Litre Turbo would be good in a Mk1

[Caffiend]

^ It must be bloody good if it's going to be shared between Tom's GT and the estate.

[RxBX]

You've got a spare engine now that you've sold WTF Tim, a 2 Litre Turbo would be good in a Mk1

Erm Matt, I don't think that's the case now

You obviously have been kept well in the dark (As Tim wanted to keep his bad dream quiet) but it may as well be 'Put to bed' now that you've mentioned it !

Take a look at this FCF thread !



.

[Tim Leech]

Sadly the tct engine is parts only as the turbo is u/s so I've sold it for parts.

[saintjamesy89]

Mulley, that is a very bad and dangerous suggestion - cos I really like the sound of it! I'm not sure how long I could have been satisfied with 105hp in a 'GT' car. If internal engine work is necessary anyway, then I REALLY like the idea of a 1.9 TCT. Use the manifolds, intercooler and turbo bits/pipework off of a 2.0 and bolt them onto the 1.9, make a carb pressure box so the carb doesn't leak due to the increased intake pressure and do some creative exhausting and carb tuning. Now that sounds attractive. Keep it carbed for the noise, but have a turbo for some powaaah!

Seriously though, is this do-able for a learning DIY-er? Would I need a different head? Would the carb survive the extra flow, and would it actually work with a turbo? Bigger jets, adjusted settings etc? I wouldn't want silly power, maybe an extra 20-30 bhp?

Or alternatively, use a TD turbo/wastegate/manifold/intercooler setup as the block is the same/very similar isn't it? I have both heard that diesel turbos cannot work and can work very well on a petrol so not sure what that's all about.

[saintjamesy89]

I've just read that 1.9, 1.9 gti and 2.0 turbo heads are near identical in regards to fitment, but have different valve sizes/combustion chamber shapes/cams. So it should be fairly easy to plop the turbo head on with all the turbo gubbins and exhaust manifold, may have to get an exhaust fabricated, but I have a thing for twin exit systems, so that'd be great! Fuelling side of things, the turbo ports are oval compared to the 1.9's 105hp's square, so a carbed 2.0 manifold from an early french XM could be the answer? Also apparently TCT cams are even milder than DFZ 105hp ones!
What about pistons?

http://websworld.org/marcel/309/tech/heads.html" onclick="window.open(this.href);return false;

[bx petrol auto saloon]

Dear Tom,
Firstly, I am so sorry to hear about your cambelt problem Tom, bu**er
Secondly, it is really very kind of Mat to offer to help out like that I hope all goes well I agree 100% with Mat, bung a belt on and compression test it
Vince,

[saintjamesy89]

Isn't he just, Vince? Thanks for your kind words