Damaged engine update

[H2DCA]

Engine now out and surprising results on the cause, engine came out fairly easily, I have stripped all the fairly new components from my engine including the front end, clutch and other components to give them a clean while awaiting replacements. First major discovery was the starter; the cowling that surrounds the sprocket that sits in the bellhousing had sheared and was rubbing against the flywheel. Speaking to my mechanic friend this is unusual and suggests it’s a result of excessive load from the flywheel, so still points to something internal to the engine. It turns with less resistance now but not as smooth as it should be.

Major discovery was the fuel regulator, I decided to test the fuel rail, so using a tyre valve connected to the fuel inlet hose I pumped air into the rail with a foot pump to see which injector was leaking, however air and residue fuel immediately poured out of the vacuum port of the fuel regulator, no pressure build up. This was the cause of the fuel issue with fuel pouring into the chamber during running.

The problem is this is a brand new item fitted the weekend before as part of the pre holiday preparations, the old regulator was running about 30 psi, a bit below optimum pressure. The unfortunate thing is I doubt I will have any come back on the damaged it has caused; I will approach the supplier and see what grounds.

I am just waiting for the new engine to arrive so patiently looking out the window in anticipation !!

Cheers
Hamish

[rev-erend]

It's starting to sound like there is no engine damage..

Just the starter motor pinion gear against the flywheel..

[H2DCA]

rev-erend said:

It's starting to sound like there is no engine damage..

Just the starter motor pinion gear against the flywheel..

Yep there was a glimmer of hope but it is not smooth turning, my mechanic friend turned it over by hand and said it just does not feel right. Something caused the starter cowling to shear and an abrupt stopping of the flywheel would have caused it. I will take the heads off the weekend and inspect the bores but going to get an engine stand so I can work on the engine.

[tempus]

Curiouser and curiouser,there should be no contact of the pinion and the flywheel except on startup,after that it should be impossible for the flywheel to have any effect on it, as for it stopping suddenly and breaking the front bearing nose cone off would mean either the crank/flywheel were loose or the starter was loose,keep us up to date with developments,Tempus

[H2DCA]

tempus said:

Curiouser and curiouser,there should be no contact of the pinion and the flywheel except on startup,after that it should be impossible for the flywheel to have any effect on it, as for it stopping suddenly and breaking the front bearing nose cone off would mean either the crank/flywheel were loose or the starter was loose,keep us up to date with developments,Tempus

I know and a few more interesting things, as for the starter and flywheel, yep they were well secured as testimony to my bleeding knuckles

Anyhow engine arrived Monday at 12.00, this is a later Chim that has the hotwire injectors etc on so as I have new items on mine, I removed them, rocker covers, sump, water pump, timing cover and oil pump and replaced them with the ones from my old unit as these were either new or refurbed plus there is variances between water porting and wiring on the engines.

Two things I noticed between the engines was that the timing marks on the old unit compared to the new unit are at slightly different places on the lower pulley compared to the crank locating key so timing would have been way off if I used my old crankshaft pulley. Secondly the alignment between the water pump and crankshaft pulley is also out, fortunately this is an easy fix with spacers behind the water pump pulley so no great problem.

All in all the engine rebuilt, everything torqued up to spec and it was back in the car by 10.00 Monday night with headers secured and on it’s mountings, yesterday everything was connected so tonight’s jobs are fluids and a few more checks.

[rev-erend]

Good progress.

Might be worth while checking the timing marks.. are now correct.

[H2DCA]

rev-erend said:

Good progress.

Might be worth while checking the timing marks.. are now correct.

Thanks, how do I do this, I checked TDC for dizzy alignment watched No1 exhaust open then fuel open and then took the crank to tdc, popped the dizzy in with alignment to No1 lead, also checked that the piston was at the top of its stroke. Is there a more accurate method
Cheers

[rev-erend]

Piston at TDC and check the alignment mark / pulley mark are correct is a good start..

Sure true tdc occurs over a range of about 5 degrees and needs to be in the middle of the dwell period .. use a dial guage but the method just using a screwdriver on the piston coming over / over is good enough.

With marking 28 degrees on the pulley to - as that's a good figuer to time to at 4000 revs.

[H2DCA]

rev-erend said:

Piston at TDC and check the alignment mark / pulley mark are correct is a good start..

Sure true tdc occurs over a range of about 5 degrees and needs to be in the middle of the dwell period .. use a dial guage but the method just using a screwdriver on the piston coming over / over is good enough.

With marking 28 degrees on the pulley to - as that's a good figuer to time to at 4000 revs.

Cheers rev-erend

[Barkychoc]

Somethings niggling away at me regarding that starter pinion business above - just make sure you're addressing the cause and not the symptom - for example if you've got some intermittent electrical problem / ignition switch problem thats causing the starter pinion to engage while the engine is running then there's a slight possibility it could happen again.
I'm just thinking out loud here I'm sure you get where I'm coming from.

Chris

[heightswitch]

Barkychoc said:

Somethings niggling away at me regarding that starter pinion business above - just make sure you're addressing the cause and not the symptom - for example if you've got some intermittent electrical problem / ignition switch problem thats causing the starter pinion to engage while the engine is running then there's a slight possibility it could happen again.
I'm just thinking out loud here I'm sure you get where I'm coming from.

Chris

Before you fire everything up. check the back cap on the ignition switch. it could be that a worn back cap / switch / conection has caused the starter to try to pre-engage when the engine was already running with bad consequences for the starter.

Audis were commonly found with this fault.

N.

[H2DCA]

Barkychoc said:

Somethings niggling away at me regarding that starter pinion business above - just make sure you're addressing the cause and not the symptom - for example if you've got some intermittent electrical problem / ignition switch problem thats causing the starter pinion to engage while the engine is running then there's a slight possibility it could happen again.
I'm just thinking out loud here I'm sure you get where I'm coming from.

Chris

Thanks, yep it was a concern why it happened but as it went bang when the engine threw a wobbly, also ignition switch is fine as this was all out of the car when the dash was out earlier this year.
Everything is now back together, I inspected all the wiring especially the starter wiring as it was well baked by being close to the exhaust manifold, this has been changed and some heat shielding will be added the weeked. I turned it over last night just to ensure oil was getting where it should be so tonight I will give it a run and a tune.
Cheers

[v8 racing]

H2DCA said:

Barkychoc said:

Somethings niggling away at me regarding that starter pinion business above - just make sure you're addressing the cause and not the symptom - for example if you've got some intermittent electrical problem / ignition switch problem thats causing the starter pinion to engage while the engine is running then there's a slight possibility it could happen again.
I'm just thinking out loud here I'm sure you get where I'm coming from.

Chris

Thanks, yep it was a concern why it happened but as it went bang when the engine threw a wobbly, also ignition switch is fine as this was all out of the car when the dash was out earlier this year.
Everything is now back together, I inspected all the wiring especially the starter wiring as it was well baked by being close to the exhaust manifold, this has been changed and some heat shielding will be added the weeked. I turned it over last night just to ensure oil was getting where it should be so tonight I will give it a run and a tune.
Cheers

I would have said the damage on the starter has been caused by the engine hydralic locking, if that amount of fuel was pouring in the engine it would bound to have hydralic locked when trying to start the engine, normally it bends a conrod!

[H2DCA]

v8 racing said:

H2DCA said:

Barkychoc said:

Somethings niggling away at me regarding that starter pinion business above - just make sure you're addressing the cause and not the symptom - for example if you've got some intermittent electrical problem / ignition switch problem thats causing the starter pinion to engage while the engine is running then there's a slight possibility it could happen again.
I'm just thinking out loud here I'm sure you get where I'm coming from.

Chris

Thanks, yep it was a concern why it happened but as it went bang when the engine threw a wobbly, also ignition switch is fine as this was all out of the car when the dash was out earlier this year.
Everything is now back together, I inspected all the wiring especially the starter wiring as it was well baked by being close to the exhaust manifold, this has been changed and some heat shielding will be added the weeked. I turned it over last night just to ensure oil was getting where it should be so tonight I will give it a run and a tune.
Cheers

I would have said the damage on the starter has been caused by the engine hydralic locking, if that amount of fuel was pouring in the engine it would bound to have hydralic locked when trying to start the engine, normally it bends a conrod!

I think you are spot on, my mechanc friend suggested the same thing tonight as we have started the replacement engine this evening, it sounded like a diesel to start off with but the combination of air leaks on the inlet chamber and exhaust requiring nipping up made it sound like it should, few more jobs and test run tomorrow.
Cheers

[adam quantrill]

I suppose that normaly with hydraulic lock the engine is already running, and water gets into it, it's the momentum of the car that keeps pushing it around and bends a rod.

However in your case it's only the poor little starter at the edge of the flywheel being the weakest point, so if you're lucky there's been no damage to any rods and the engine just came to a full stop and snapped the starter. Worst case would be one bent rod before it stopped.

Edited by adam quantrill on Tuesday 14th July 08:24

[H2DCA]

As mentioned the car started fine, set the timing but still sounded off so attached a plug to each leads and saw very good sparks, took it for a run and it was missing on a few cylinders. Popped a new set of plugs in but noticed that 3 of the plugs were very light brown compared to the others. I am thinking possible fuel as sparks are good and treble checked leads are on the correct plug, fairly new dizzy as well, all LT leads are good as these were checked when the engine was out. Could my injectors be a problem, fuel starvation, I am thinking about popping the old set back in ?

[adam quantrill]

.. or swap one with a 'good' cylinder and see if the symptoms follow the injector...

[B@man]

adam quantrill said:

.. or swap one with a 'good' cylinder and see if the symptoms follow the injector...

.... you beat me to it !

[H2DCA]

adam quantrill said:

.. or swap one with a 'good' cylinder and see if the symptoms follow the injector...

Ah just got to this as combo of butt in the air under the bonnet last night and work but changed all the injectors out for the old ones and hey presto its as it should be, nice idle and nice transition through the rev range. Test run last night, not too many revs as shaking it down but smooth and flexible and very responsive. Such a relief as its only 11 days before the euro hoon ! Few more jobs, check the timing again tonight, I have fitted ducting to the rear ducting to cool the rear brakes as they cooked last year over alpine passes so need to secure these better, fit a new anti roll bracket and a good long run the weekend.

Thank you for all your advice and help
Hamish