[james008]

LPG filling issue is fixed, it was the AFL valve.
Theres only one LPG certified mechanic left near me, and I ended up paying them to fix it due to time, parts availability, losing all my LPG with no auxiliary fuel system and not wanting to blow myself and/or the car up issues.

For the price I ended up paying and the slight ego blow of paying someone else to fix my car for the first time, I probably would have been better off blowing myself up, but anyway…

I’ve pulled the engine

Due to the massive bellhousing extension, the clutch is a real odd ball set up. The factory pivot fork and bearing retainer are kept, but there’s an extension housing pressed on, then another small extension for the throw out bearing to be pressed on to. And there’s an extension for the Nissan input shaft to convert it to the Chevy 10 spline pattern.

All those parts seems absolutely fine, including the throw out bearing which seems like it was replaced with the clutch. aside from the support hole being horrendously off centre in the bellhousing, it seems fine too, and the throw out bearing extension and input shaft move through it just fine, so it’s not an issue.

At this stage, I have no idea why the clutch is grinding.
I’ll pull the pressure plate and disc off, maybe there’s some crap in there? Or the spigot bush might be junk, allowing things to move around? I dunno.

I have 10 days until my first engineering session, which is reduced down to a few evenings due to other commitments, to diagnose, find parts for a nearly 60 year old American engine shoved into a 40 year old Japanese car, fit them and reassemble everything.

So things are going well.

 

[dkril]

They're certainly going about as expected.

 

[dkril]

The first automatic suggestion for the last word in the previous post was, "expensive", which would probably have been appropriate too .

 

[james008]

Forgot to mention above, the input shaft bearing also feels okay by hand.
It’s a ball bearing, so there’s always a bit of play, but not enough for the shaft to contact the snout that it runs within, and loading the bearing by hand there isn’t any crunchy parts.
The whine in gear that increases with RPM still suggests that it might be on its way out, but if I can’t get one on Monday, that’ll be a problem for later.

I think I might have figured out the clutch problem.
The spigot bush is flogged.
It should have an ID of approx 15mm, or 1.03 grapes and a walnut leaf in imperial sizing, which is approx 0.59”

the part of the bore where the input shaft rides has been flogged out to 17.7mm, which is probably not great.

I used the old bread trick to remove the spigot bush. It took approximately 5/8ths of a hot dog bun.

If the bushing doesn’t fix it, I’m not sure what my next step will be. But petrol and a match is a pretty good chance.

 

[james008]

The first automatic suggestion for the last word in the previous post was, "expensive", which would probably have been appropriate too .

Expensive is about right.

Between the cost of parts and the hours of labour, and the upcoming cost of making the poor little 327 act like it should. I.E not floating valves under 5000rpm, I’ll be pretty deep in the red.

 

[james008]

Engine is back in.

I had thought the input shaft may have been moving in and out, causing the massive wear of the old spigot bushing, so I had an oversized bushing machined up, so I could cut it to suit.

despite measuring and cutting the bushing to wear it should have worked, the engine and trans wouldn’t mate, I didn’t account for the engine and trans mounts relaxing, so my measurements were a few mm off.
Ended up just knocking in a standard size bushing, but leaving it about 2mm proud of the crank.

Good news is the clutch doesn’t seem to grind anymore.

Had to replace the starter too. New one is tiny. Cranks the engine over much faster though. And with less grinding and smoke, which I appreciate.

engineering development session is tomorrow. It’s an hour drive away, so we’ll see if the Ute makes it with no fires or major mechanical failures…

 

[james008]

The engine stalled today while I half way out of the shed, and refused to restart for half an hour.
I have no idea what happened, but I messed with some wires and threatened to burn it to the ground, and it started again.

The nearly 1.5hr drive to the engineers was a bit nervy, not knowing if it was going to crap out again, but it ran alright there and back aside from a few death wobble issues and running at 100 degrees most of the time lol.

And I got my list of things to fix, nothing too bad, just annoying stuff like not enough clearance around rad hoses, exhaust, bell housing, a few holes in the fire wall etc.

Checked timing, figured that could be related to it running hot.
Holds 12* btdc at idle with no vac advance, and seems happy there.
But at 2500rpm the timing was jumping from approx 40-55* with no vac advance, no idea what’s going on there, but I didn’t hear any pinging and it didn’t melt a piston, so I dunno what’s going on there.

 

[james008]

Finally got to look at the tune up of the 327 again.
Still NFI what’s going on with it lol. Timing is all over the place, and there is bugger all vacuum at idle.
The most I could get at an idle of 800rpm was 3-4in/hg with the timing at 20* BTDC or something stupid.
I’d expect 15-18in/hg for a pretty standard small block Chevy.

The vac gauge seems to work, tested it with SD33 vacuum pump, which showed right around 18in/hg.

Spraying the carb and intake with brake cleaner didn’t find any vac leaks either. So I dunno.

Maybe I’m missing something, but I don’t know the engine runs with so little vacuum and so much advance. I can’t hear any pinging either…

 

[Kadina]

Finally got to look at the tune up of the 327 again.
Still NFI what’s going on with it lol. Timing is all over the place, and there is bugger all vacuum at idle.
The most I could get at an idle of 800rpm was 3-4in/hg with the timing at 20* BTDC or something stupid.
I’d expect 15-18in/hg for a pretty standard small block Chevy.

The vac gauge seems to work, tested it with SD33 vacuum pump, which showed right around 18in/hg.

Spraying the carb and intake with brake cleaner didn’t find any vac leaks either. So I dunno.

Maybe I’m missing something, but I don’t know the engine runs with so little vacuum and so much advance. I can’t hear any pinging either…

Great build up thread!

That vacuum can't be right, are sure you are measuring on the correct side of the butterfly.....

 

[mistyv6]

hanst got a hole in the brake booster

 

[dkril]

Are the advance weights in the distributor in good nick?

 

[james008]

Great build up thread!

That vacuum can't be right, are sure you are measuring on the correct side of the butterfly.....

hanst got a hole in the brake booster

Are the advance weights in the distributor in good nick?

thanks all.
I was measuring vacuum straight off the intake manifold, bypassing the brake booster.
And the dissy seems okay, it’s an electronic one with no throw out weights that I can see, but it can be advanced by hand and spring back with no issues.

I have made some progress.
Bought a new vac gauge. This one reckons the engine pulls 11-12in/hg at idle after a quick fiddle with idle speed, mixture and timing.

I had assumed the other one that I used was right. It suggested 18in/hg of vacuum on SD vacuum pump, which kinda lines up with the test spec in the service manual of 19.69in/hg, plus a bit of inefficiency in the pump after 44 years. Apparently that was not the correct assumption.

I’ve made a piston stop as well to verify TDC, which was right, but I made a couple of new timing dots on the balancer, so I didn’t need to use the dial in advance on the timing light. That fixed the jumping issue. Timing is currently 18 initial and 32 with centrifugal.
High initial and low centrifugal advance is right for LPG from what I gather.

the engine really seems to like timing. It was perfectly happy idling with up to 30 degrees initial, and revved up clean with no audible pinging, but there was almost no improvement in vacuum so I backed it off. I’d prefer not to melt pistons.

 

[GUEY]

Bump
6 months on James. How is things going with it?