If not a p38 or discovery2 ?

[Pinger]

This is what Mr Mercruiser says about fitting the heads on the V6, the Vortec is what they refer to as the Gen+ engine.

Screenshot 2023-09-02 191102.jpg

No mention of the bolts being one use at all.

The fitting advice chart I posted earlier is also Mercruiser's apparently. Note reference to obtaining bolts locally.
It is from this (short) thread here >> https://www.gmt400.com/threads/late-mod ... lts.60304/
My take is that if the heads are 1/2'' AF then they have to be replaced.

There wasn't much feedback re my sealant question other than saying that new bolts come with sealant pre-applied.

[LPGC]

I haven't looked into the GM stuff, enough on my plate looking into the Ford stuff I'll be needing lol, but I bet Gilbert knows if his bolts are stretch / tty bolts and need to be replaced.

The Ford head bolts are not stretch or tty and a lot of owners re-use them during rebuilds. But if I were to buy new head bolts (at this stage I'm getting near completion and I haven't bought any so it doesn't look like I will be fitting new head bolts) it doesn't seem new OEM Ford head bolts or the more expensive ARP bolts are pre-coated with sealant... So at least for me there's still the question of what sealant to use on the old bolts when I re-use them.

[Gilbertd]

My bolts do have a 1/2" hex head but no mention in the manual about not reusing them. I'll ask the place that is re-boring my block and, if it is recommended to replace them, I'll get them to send me a set. Latest news is that one of the main bearings has spun in the block/cap, so their block man is having a good look at it to see if he reckons it's OK to use it or if he thinks it needs a replacement block. Personally I can't see a spun bearing doing much damage to the block itself, I'd expect the tags on the end of the bearing to just be a bit flattened.

[LPGC]

I had a conversation today with another Yorkshire based LPG installer, they don't do many installs and don't claim to be really clued up re LPG conversion installs, an honest bloke who phoned to pick my brains on the advice of Mick from LPGautosupplies. Their main line of work isn't installing LPG conversions, they do a lot of general spannering work on American stuff. During our chat he told me that he recently had to hold his hand up to fitting main bearing shells the wrong way up on a Chevy V8... The damage caused by doing so (which will have led to the spun bearing) caused the shells to weld themselves to the crank but luckily he has a spare crank.

[Gilbertd]

Oddly, I didn't take any of the main bearing caps off (just covered the big end journals in masking tape when honing the bores) but the crank spun nice and smoothly so I can't see it being that bad. There's a heavy torsional damper on a keyway on the front of the crank which I couldn't get off no matter how hard I hit it (reading the manual later and there is a proper tool for pulling it off). That meant I couldn't take the front cover off to get the crank out anyway otherwise I would have seen it.

[Pinger]

My bolts do have a 1/2" hex head but no mention in the manual about not reusing them. I'll ask the place that is re-boring my block and, if it is recommended to replace them, I'll get them to send me a set.

Me joining that GMT 400 forum coincided with me joining this forum (for obvious reasons) and there are a few guys there who's knowledge I trust - as I do on this forum. IMO those guys are as knowledgeable about SBCs as you guys are about LPG systems. The advice about replacing 1/2'' headed bolts isn't advice I'd personally go against. That said, your comments echo Schurkey's re the vagueness of Mercruiser's advice.

Latest news is that one of the main bearings has spun in the block/cap, so their block man is having a good look at it to see if he reckons it's OK to use it or if he thinks it needs a replacement block. Personally I can't see a spun bearing doing much damage to the block itself, I'd expect the tags on the end of the bearing to just be a bit flattened.

Spun bearings weren't really on my radar until I joined the GMT 400 forum where it seems to be the failure mechanism of shell bearings. Prior, I just thought that a shell bearing wore (no spin) made a noise and leeched oil pressure when it failed. At a guess, I suspect you are correct - ie the block survives the incident.

[Pinger]

Oddly, I didn't take any of the main bearing caps off (just covered the big end journals in masking tape when honing the bores) but the crank spun nice and smoothly so I can't see it being that bad.

Worth lifting the caps given you're that far in? Personally I would (having being stung this way before) unless the big end shells and journals were immaculate and indicative of the rest of the crank.

There's a heavy torsional damper on a keyway on the front of the crank which I couldn't get off no matter how hard I hit it (reading the manual later and there is a proper tool for pulling it off). That meant I couldn't take the front cover off to get the crank out anyway otherwise I would have seen it.

I modified a puller (see photo) to remove my damper but didn't have the correct tool to press it back on so had to use its retaining bolt on refitting - far from ideal and not recommended to anyone with less pressured time constraints. Better though than hammering it back on which can damage the crank thrust bearings.
I only recently learned that I should have applied a spot of RTV to the key on refitting. Almost certainly the cause of the oil weep I have. Never severe enough to cause a drip but annoying nonetheless. In the confines of a boat hull, possibly more annoying.

[LPGC]

There's a heavy torsional damper on a keyway on the front of the crank which I couldn't get off no matter how hard I hit it (reading the manual later and there is a proper tool for pulling it off). That meant I couldn't take the front cover off to get the crank out anyway otherwise I would have seen it.

I bought a special tool for pulling my engine's harmonic balancer / damper, it's really just a heavy duty bolt type (as opposed to clamps on legs type) pulley puller tool like @Pinger pictured but is designed so it can work on pulleys with 3 or 4 bolt holes. You could borrow it but I think it was 'only' around £40 to buy. I intend to try re-installing it using a wooden mallet (not hitting it very hard) or failing that just use the damper bolt to pull it back in. There's a fair bit of torque on the damper bolt but mine came off easily using a rattle gun.

Edit - This is a lot like the one I got (maybe if this one has UNF bolts it is the the one I got), obviously I made sure that the supplied set of bolts included the necessary UNF bolts.. https://www.machinemart.co.uk/p/clarke- ... ce-puller/ . Can't remember if I got it from MachineMart or Amazon.

[kbs]

Would manage ~5.5 kts

Hmm, not going to tow a water skier then.....

Hull speed of 6kts, only ever reached when being towed by RNLI after an incident with stray fishing nets.

[Gilbertd]

The Mercruiser puller is nothing more complicated than a big bolt. The torsional damper has a thread on the inside so screwing the bolt in just pulls it off the end of the crank. However, I didn't see that until I had strapped it to a pallet ready for it to be collected to go to be rebuilt. I took the big end shells off, had to really to get the pistons out so I could hone the bores, and they looked fine. I measured the crank pins and they were in spec so figured all the crank would need would be a light polish and a replacement set of standard shells. As it is now about 130 miles away, I can't do any more inspection on it but I've been told I will hear the verdict Monday or Tuesday next week.

[Pinger]

I intend to try re-installing it using a wooden mallet (not hitting it very hard) or failing that just use the damper bolt to pull it back in.

I refitted mine using the damper bolt but there's always the risk of stripping the threads in the crank. A length of threaded rod with a nut would be a lot kinder on the crank threads. That's how I'd do it if I were doing it again unless I had the correct tool. If that keyway leak continues to annoy....

[LPGC]

I intend to try re-installing it using a wooden mallet (not hitting it very hard) or failing that just use the damper bolt to pull it back in.

I refitted mine using the damper bolt but there's always the risk of stripping the threads in the crank. A length of threaded rod with a nut would be a lot kinder on the crank threads. That's how I'd do it if I were doing it again unless I had the correct tool. If that keyway leak continues to annoy....

Good idea but it'll have to involve a bit of strong pipe around the bolt because the harmonic balancer is quite deep, also being deep will have to buy a long setscrew or length of threaded bar in the correct (widest bolt on the engine I forget how wide and whether UNC or UNF) thread.

[LPGC]

During engine disassembly when I removed tappets and pushrods I kept them all in order, since then they've got mixed up! I'm not expecting a problem from that because it seems the engine had been rebuilt not long prior to my re-rebuild and there's little wear on those components.

But the other day, knowing the above, I went to try different tappets in different tappet holes (for want of a better term) in order to find the best smooth fits for them all. Then I realised that I hadn't even cleaned the heads up yet (and I should have the heads ready to fit after fitting tappets). I spent some time yesterday and today cleaning the heads up and was surprised to find some pitting on the heads, surprised because the decks of the block are in great condition. I'm not too concerned about the pitting around coolant channels but I am a bit concerned about the minor pitting around some of the fire ring areas. I haven't offered the head gaskets up to the heads yet to see how the pitted areas relate in position to fire rings but I think I can see just by looking at (even the cleaned up) heads that there's some pitting in a circle around the cylinders under fire rings.

[Pinger]

Tripped over this >> https://www.youtube.com/watch?v=d8zRGu5Xbkk&t=501s Go to 6m 39s for a Vortec balancer being fitted using the correct tool. Gives an idea of what such a tool comprises. An improvised alternative could be simpler - just need to avoid the tightening/rotating being done on the internal crank thread - which in the case of a Vortec is 7/16'' 20TPI - which would make it UNC (I think),

[Gilbertd]

As mine was still on the crank when it went away, I'm hoping it will have been put back on when I get it back.....

[LPGC]

I took my heads to a local engine builder (specialises in American stuff) to get a second opinion on the pitting. He said they weren't too bad but if it were him he'd have them skimmed. I hadn't even stripped them down (removed the valves, rockers or engine lifting eyes) but the engine builder put phoned his mate who runs a machine shop just around the corner, the machinist told me a price on the phone and I took the heads straight to him without stripping them first.

I knew I should've stripped the heads first... The machinist reckons he had to remove the rockers but put them all back on loosely in the same place they came off from (kept them in order). Also said he only had to remove a few of the valves. I'm not sure he did either of those things (other than loosening rocker bolts), seems he didn't need to remove the lifting eyes... But he did skim them and they look better for it. I asked what the valve seats looked like and if there was any play on valve stems, he said those he removed were all good. Hmm I don't know now whether to remove valves to check them etc. I will be chasing the threads in the heads that exhaust and inlet manifolds bolt to. I suppose I'd better remove the valves and check for bends / play / chips / etc, eh? Maybe a bit of a regrind with fine paste?

[kbs]

Did I suffer a brain fart?

I want a Ulez (bristol) friendly discovery or l322.
Last time I checked (I think) the possible options were;
Disco2 4ltr, disco3 4.4 (bmw), l322 4.4 (bmw).

Looking again, it's only the discos that comply.

[Pinger]

Good news re skimming.

I asked what the valve seats looked like and if there was any play on valve stems, he said those he removed were all good. Hmm I don't know now whether to remove valves to check them etc. I will be chasing the threads in the heads that exhaust and inlet manifolds bolt to. I suppose I'd better remove the valves and check for bends / play / chips / etc, eh? Maybe a bit of a regrind with fine paste?

That far in - I'd definitely give the valves a lapping. Wont there be new valve stem seals with the head gasket set that require valve removal to fit?

[LPGC]

That far in - I'd definitely give the valves a lapping. Wont there be new valve stem seals with the head gasket set that require valve removal to fit?

I'm rebuilding this engine between work commitments, the engine was recently rebuilt before I bought the boat and for the most part the rebuilder seems to have done things right (but obviously no cigar because I'm having to rebuild it again lol). It does seem to have new valve stem seals or at least they seem to be in very good condition. I spent most of the time I had working on it yesterday chasing all the threaded holes in the heads to make sure the exhausts and inlet manifold bolts will torque in properly but I did remove the exhaust valve that was on cylinder 2, the valve, seat, stem clearance and stem seal seam fine. I might have had time to remove the inlet valve on cylinder 2 but it seems the collets ride inside a cap that itself rides on the spring retainer... and the collets are holding the cap up even with the spring compressed and away from the cap/collets. Not something I want to force / bend, I'll probably have another go when I've got a bit of time at getting all the valves out.

I also need some new head dowels, easy to get hold of if I were in the US or AUS, not so easy to get hold of here.

[kbs]

Did I suffer a brain fart?

I want a Ulez (bristol) friendly discovery or l322.
Last time I checked (I think) the possible options were;
Disco2 4ltr, disco3 4.4 (bmw), l322 4.4 (bmw).

Looking again, it's only the discos that comply.

London ULEZ is easier than Bristol?? A car that is not exempt in Bristol, check TFL and it is exempt. Currently cant find logic in this.

If it wasn't for my local family, I would move north....