Trying to fix Volvo Penta 2001 that refuses to start

[E26-2]

Originally Posted by nick.theboatman

Absolutely - wll maybe 275... so where's it leaking?

No diesel will run at that low of a compression. . Check the rod .make sure it's not bent .

[nick.theboatman]

Originally Posted by E26-2

No diesel will run at that low of a compression. . Check the rod .make sure it's not bent .

<sigh> back to step -5 it appears.

So we got the compression up to 375psi with some oil (see previous posts) and got some compression sealer gloop that we hoped would sort that out until the new rings were bedded in.

But before it arrived...

The engine stopped. One of the nuts fell off the big end bearing cap; the thread was completely stripped by the time it had finished; the other bolt was bent at 45 degrees. The shells were mashed. In the process of getting a big dent, (and distorting the big end shell socket so that between-centres was 10mm less than the end cap) the connecting rod smacked a chunk out of the bore (but fortunately below the oil scraper) ... miracle it didn't go through the side of the crank case. Oh and the big end journal had a couple of 500um dents in it.

So my first mistake was not making sure that when he fitted the new bearing shells that (a) he had inspected and measured the journal and (b) used a torque wrench on the nuts..

But we found out some other things at the same time...

1. The big end journal was not so much -500 undersize as -2000 undersize - god knows where those shells came from - so when he fitted true-size shells it was clattering around like hell - not surprising there was so much vibration :/

2. Volvo Penta was the reincarnation of Bollinder. Big respect. The Penta 2001 was known as the "Baby Bollinder". One supplier said "when these came out we thought that they wouldnt last very long - but 35 years later and they are, only now, being retired; Bollinders are basically bulletproof so it looks like these were as well". Interesting...

3. You would not believe how hard it is to find parts but (if anyone doesn't know) this is useful:
https://www.volvopentashop.com/epc/en-GB
(select your country obvs)

4. You can build up a mashed journal with weld and get an engineering shop to grind it back. But they need to be one with an offset crank grinder and a dimension to work with - if the journal is filled up with weld then the datum axis is lost; this is a calibrated offset from the shaft axis. Whatever that number is... (out of the data book actually).
And TIG is better for building up. No valleys. And watch for warping.
But this approach means that you can go back to true size and from then on everything else is peachy. Maybe.
New shaft? From the US? $1600 and $75 shipping...

We found one engineering shop that we thought could do the journal. "How big"? "52" "Oh that's a bit small - we can't go down much below 100... Did you say it was a bulldozer or a train?"

5. A new engine might have been a good idea if we found one at the beginning.

So...
Never a dull moment.

[Wotname]

Crikey, you are not taking many wickets. What's the game plan for the next over?

[nick.theboatman]

Originally Posted by Wotname

Crikey, you are not taking many wickets. What's the game plan for the next over?

Shooting. With an assault rifle
Actually I've just spoken to a very helpful ex-boat-builder called Mick who said that he built quite a number of short narrowboats with these in (may years ago) and yes they are bulletproof. He weighed-in all his old stripped-out unit stock, unfortunately, but somewhere there must be a repository of good parts...
And if not maybe we should make one..

[Lou-In-NJ]

Wow...and you don't even know what the deal is with the low compression yet either. You have to mic everything when you replace bearings,pistons & rings. If you don't have the instruments, then take it to someone who does. As I said earlier, these aren't things you can visually inspect or measure; there's no Foucault knife-edge test for these parts.
The old adage proves true again: You never have time to do it right the first time, but somehow there's always plenty of time to do it right the second time around.

[Icarus]

Welding a crankshaft journals is definitely not a bright idea. Crankshafts are surface hardened and welding wil be difficult apart from most likely distorting the shaft.
To properly rebuild a worne and damaged diesel engine cost money and requires mechanical know how.
Maybe it would better to replace the engine?

[nick.theboatman]

Originally Posted by Icarus

Welding a crankshaft journals is definitely not a bright idea.

Actually this is a recognised way of repairing an old crank especially one that is out of production. He did a good job of welding the journal.
We did find a new shaft:$1600. So why is welding a bad idea?

Originally Posted by Icarus

Crankshafts are surface hardened and welding wil be difficult apart from most likely distorting the shaft.

Welding will give some hardness as well. As for distorting, this is a one-pot crank so the risk is low and even if it does, it will affect the mains only slightly and the new journal surface will be made anew on a new profile so a bit of distortion is irrelevant.

Originally Posted by Icarus

To properly rebuild a worne and damaged diesel engine cost money and requires mechanical know how.

So just as well that between us we have 120 years of experience (and one of the team used to run a garage - and I'm a Chartered Engineer.
But apart from that...

Originally Posted by Icarus

Maybe it would better to replace the engine?

I think that you must have missed the bit above somewhere ^^^ about the investment already put into this engine - so past the point-of-no-return... and anyway there is a matter of principle: "we're going to fix this vintage engine.

I've been posting the unfolding story here so that if someone is in a similar position perhaps some of this might be useful and give heart to someone down a hole, no spade and the hole is caving in...

So with respect your post isn't particularly helpful. Please excuse the harshness - but really...

By the way we hit another issue with this story.
Having welded the crank we found that the predominant machines used to regrind (Prince 6075, Schou 2200 or AMC K1200 or K1500) all require a journal to follow in order to grind the new surface. So essentially precluding a 1-pot engine. The motorbike maintenance community was very helpful. We worked out a method to address this having studied several GooTube videos (search on the machine numbers) including several US ones (and the Americans are just so anal about using micrometer clocks lol l - did a good job by all accounts):
Procedure:
1. centre the crank on the machine (each end chucks) by clocking on the mains.
2.Guess the index from the crank counterweights; maybe fiddle a couple of ties if it loosk "wrong"
3. Step the chucks by the amount in the data book
4. Grind the journal to the true size spec from the data book.
Cost of the job: probably an hour. £70. Maybe.

£70 <-> $1500 .. See why, now?

[Wotname]

Thanks for the update, Nick. Looking forward to the next one!

[nick.theboatman]

Originally Posted by Wotname

Thanks for the update, Nick. Looking forward to the next one!

Well that was a saga and a half. (Note to self: "Don't go and agree to help rebuilding a Penta, Nick...")

So the crank shaft was eventually weighed in. We found someone who agree to do the job but he said that the welding might crack at the weld-base-metal interface (although this was unlikely) but it was more likely to break in half on first use because of the stress introduced because of the welding. He said "can be done but you have to laser weld and that usually costs something like £500 a journal". The client found a new crank (still in the original Volvo bag) so that was that.

Then we had 2-3 weeks of messing around in which I did other things and he rebuilt the engine.

The main thing (which seemed to track back to the very beginning) was the poor compression. On first reassembly he got 490 psi (!) but this was back to 140 after a few passes (and the rings settling in). We took some of that thick goo in bottles to it and that sealed it up quite fine. A good 290psi on cold start and she now fires on the key.

We also found that the valve timing was well off when set to the "proper" setting (pips lined up on crank/cam gears) and she just wasn't having it. When we skewed the cam by 3 teeth she was good to go.

We also found that the injector timing needed some work - the number/methodology in the book seemed to be ok and as he had been through a couple of gasket sets by now we had plenty of injector pump shims. The plastic ones seemed to be terrible.

So the engine now runs very well, ("**** hot" - technical term) looks the business, went back in the boat Monday (1/2 hour of happy messing with scaff poles and a chain winch - amazing what one gets up to at the wharf...) and the boat was sold this evening.

So all's well that takes 2 months of trauma and strife and lots of unexpected money ...

Onwards and upwards.

[Wotname]

^^ thanks for the update Nick. Good to hear a solution for the valve and injector timing was found.

I will remain mystified by the compression - I wonder for how long the magic of the "thick goo in bottles" will last but it seems that will be something for the new owner to discover.

[nick.theboatman]

Originally Posted by Wotname

^^ thanks for the update Nick. Good to hear a solution for the valve and injector timing was found.

I will remain mystified by the compression - I wonder for how long the magic of the "thick goo in bottles" will last but it seems that will be something for the new owner to discover.

This stuff: https://www.ebay.co.uk/itm/292300717483
Well it glued it up good n proper

[Wotname]

Originally Posted by nick.theboatman

This stuff: https://www.ebay.co.uk/itm/292300717483
Well it glued it up good n proper

Hang on, that stuff is only good for 4,6 & 8 cylinders - didn't ya read the bottle.

Seriously though, you have definitely proved it works and I guess if it loses compression in the future, all you have to do is whack some more in.

[nick.theboatman]

Originally Posted by Wotname

Hang on, that stuff is only good for 4,6 & 8 cylinders - didn't ya read the bottle.

Manufacturer's Warning: Don't use the bottle marked "Warning only for use in gluing up a 4-pot engine" in a 1-pot engine


Actually he put in 1/4 of the bottle.. then the rest

Originally Posted by Wotname

Seriously though, you have definitely proved it works and I guess if it loses compression in the future, all you have to do is whack some more in.

Yes it does, that. I don't know how long it lasts but it seems to glue the rings into the channels in the piston. Obvs the bore was off-round - just goes to show how critical compression really is.

I think there was a lot to be said for the difference in stroke between the old crank (which had the "no bearings" option) and the new crank. The piston stroke went from "5mm below the head" to "might bang the head - well its ok it will all bed in sort of thing"