Time for a 3 month update.
No, haven't done much, spent most of summer painting a fence, not even mine and not even getting paid, Karate kid style.
This is just the 72 block, the 74 I've done nothing with and still haven't finished the crank for the 75 block. The crank grinding machine is still at my work but had to move it a few feet which means I can't plug it in so it won't go. The answer to that is ridiculously simple but we won't go there for now.
That mark that's left there, that's the one and only reason why you resurface the heads, it's corrosion and it's porous......you can't resurface a bent head as it's bent and the cams won't work.
It affects cam timing?
No it doesn't, it's immeasurable as far as timing goes.
Same reason you resurface the block....corrosion. A freshly machined surface won't leak.
But my block hasn't been resurfaced., it doesn't need it. there's no corrosion on the block, but I've seen first hand how a block looks before and after resurfacing, corrosion can be extremely hard to see and .(need to know what to look for)...like in the case of for example an XR6 turbo........if you do a HG job on it and it still leaks......hahahhaha, you forgot the block. do it again only properly.
OK so after 3 months I've done the club sandwitch thing, RTV, thin HG, more RTV, 3 mm spacer, more RTV, thick HG, more RTV, then the head.
I've done it in stages, sort of.......left off the last part with RTV, put the heads on, partially torqued to remove excess RTV. let it dry, remove heads, scrape off.......etc.no blocked holes.....they even line up, I think I read on the interweb somewhere tat they don't?
I've even reused the shitty old composite headgaskets, can't do it without the RTV though.
Because it takes so long, you look at it carefully,get dirt, there's a mark just below the top of the bore, that's where the top ring gets to at TDC.
I've also fitted the lower plenum , gaskets and spacers. Done the same with the RTV, got to cobble up some sort of leak tester........'cos it'll leak?
I fitted the knock sensor too, it's so much easier before the heads go on.
But before that I had to use the signal generator and oscilloscope just to verify it's a good one and the right frequency output.
I've torqued the head bolts 70 ft lbs, left for a few days, put paint marks on facing the front, backed off one on each side, retorqued to make sure paint marks end up where they started , as they do.Then I retorqued them all to 80, took note of how much extra angle it takes...because I can?...it'll come in handy later......80 ft lbs is enough.
Headlift?......what's that?....it doesn't exist....it's just more BS from murica.
The heads distort .......like blocks of rubber.....they distort and unseal between the bolts but only if you use the wrong heads to start with and then do really silly mods to them.....like grind away the divider between the intake ports............AND pay for it too..lol.
I've got the belt fitted now, a bit unsure on the timing marks.
I've already degreed the cams but with different heads. Because the seats have been recut and because the valves have been refaced, the tappet clearances will be a lot less, so got to start all over again, reset the clearances then check the open / close points and centrelines.
The cams and camtrays still need stripping and cleaning but that's the last job before they stay on for good.
There's the offset pulley on the right hand side for getting the rear bank adjusted, I've also got a bit of up / down adjustability in the water pump. That gives adjustment to the front bank. The bracket to the intake manifold doesn't fit but I can make it fit later on once it needs locking in place.
What about the solid tensioner?..I cobbled it together in about 15 minutes....what do they cost at 3SX?...US 119.95???? ...you'd need a few brain cells missing to buy one?...but no....it's just for degreeing the cams. You'd never run a real engine with one?........or would you????
Edit. this ewetoob is worth watching
It's still a V6 but ally block, lots of similarities.........like the bore spacing is the same so a Nissan VR / VQ crank actually fits a mitsi 6G block, sort of......not that I'd expect anyone else to know?The main journals are 65 mm compared to the 74 at 64 mm and the 72 at 60 mm. The big end journals are 56 mm compared to the 74 crank at 55 mm and the 72 at 50 mm....so at least in theory I could rework one to fit a 74 block.....then it's just the flywheel, oil pump and front pulley to worry about.
Cranks crack and headgaskets leak.......old news. You'll often see a crack in a big end journal after it's spun a bearing but you won't see it until you clean it up by regrinding on the crank grinder machine. Likewise I've seen 2 broken cranks, both stock and diesels, one a Nissan the other a Mitsi.
80 mm turbos like my new ones will make a gazillion PSI of boost....good to know.
That Andre fella, the same one that said to me some 15 years ago when looking at my TT heads at speedtech...........he said.......you wouldn't want to use those for a race engine.
So I haven't since.
Not that it matters but why do other people still do it?
When it's those same people will tell you how good a 4G63 downgrade is?????
Only because they can make the expected numbers with a 4G but can't with a 6G.
Must be rocket science?
Or maybe it's just that one of the definitions of insanity is doing the same thing over and over and expecting different results.
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....