When you get better heads, why don’t you just o-ring the head and run it? Or make a jig and o-ring the block and run it? I feel like that would solve your issues pretty easy
Twins with Twins, Anyone?
- Thread starter kidturbo
- Start date
Every option is an unknown gamble, without going back on the dyno first.
I picked up the old heads and the spare castings Sunday. We cut one .022 and it cleaned up fine. Valve is still .015 down in the head. But the mill grabbed some carbon from somewhere on slow cut, and scratched the crap out of half it... So both headed to a different mill with 20RA finish stones. Hopefully it cleans back up in under 005... If so, we golden.
Unless PPE seriously wants to see their heads setting under Gale's name plate, I doubt you'll find cast iron units on VooDoo anytime soon. Now if someone steps up and lays down some serious coin, I'd be glad to continue the R&D back on the dyno until it's solved. But for now, the easy fix is just turn her down a bit. Six figures a year, for 6yrs is what it cost to get it to 90MPH...
You’re right but you have concluded that the current option can’t hold and that based on theory, others running o-rings with success albeit NOT in a boat motor and calculated loads, an o-ringed block/head is a more viable option to width stand floating/movement. I cannot think of a reason it wouldn’t not benefit you. Truely, you need to fire ring it or deck plate it but that’s not an option at your current state.
I wouldn’t not be near as worried about the valve depth as I would be about the arch you are going to put on your rocker bridge. You can machine down the intake side to make up for the heavy main cut but you can’t really make up for the rockers like I pointed out in the thread you linked. May never be an issue or you may start running into valve train issues. I’d be curious to see just how bad it is.
It's very hard call when you have two identical engines, and one is on it's 3rd set of heads in 150hrs. Yet the other has never spit out a drop. I'd be willing to bet, that port engine probably pass the 24@80% test as is. But for this one, I am also picking up the fire ring tool from my buddy when I drop off the heads. I'll ask his thoughts on doing these heads, since be last cut for sure anyways.. Not much worried about the intake, has 14" runners.. But that jacketed 316L exhaust is pretty dang rigid. 
Reason I want to see this solved correctly, 900hp was my "magic" safely number. Yet if ya read back to page 20 or so, my crazy Aussie brother had his heart set on 1000hp+ from sub 7.0L.. Just a silly number, yet neither has ever been achieved in the marine world. Many have tried, all have failed. These being the only two contenders even still running in that race. Just a silly bragging rights race at that. You can today buy a 1350hp 9.7L gasser with a warranty for same cost as these. Yet at 200hrs, you buy them again. Called a Rebuild.. LOL.
So after a good year of thoughts and coming to grips, all involved agreed that passing this torch to someone else in a dang good starting position, would be the best plan. As it was rigged for David, rather than pieced out. Which was a really tough call when one engine, both transmissions, and drives, all have been spoken for on moments notice.
Reason I want to see this solved correctly, 900hp was my "magic" safely number. Yet if ya read back to page 20 or so, my crazy Aussie brother had his heart set on 1000hp+ from sub 7.0L.. Just a silly number, yet neither has ever been achieved in the marine world. Many have tried, all have failed. These being the only two contenders even still running in that race. Just a silly bragging rights race at that. You can today buy a 1350hp 9.7L gasser with a warranty for same cost as these. Yet at 200hrs, you buy them again. Called a Rebuild.. LOL.
So after a good year of thoughts and coming to grips, all involved agreed that passing this torch to someone else in a dang good starting position, would be the best plan. As it was rigged for David, rather than pieced out. Which was a really tough call when one engine, both transmissions, and drives, all have been spoken for on moments notice.
C's, reliefs, and a sub deck protrusion, on stage1 cam. 5800R's sustained, not even a dusted soot spot.. We Good
I was just wondering if anyone had ran the valves below deck. Could be something like those piston dimples..
Also as James mentioned above, the biggest concern in milling these heads, remains valve train angle. With previous setup, say .015" max cut being where this last pair landed on the deck, I spotted no sign of premature wear on any push rods or rockers, or bridges. Even after being thrashed on for 100hrs.
Has anyone ever tried to shim the rails, with recessed valves, when running studs? Another set of "Shorter" rods would be easiest, but we're only talking .008 from where they currently run.
Has anyone ever tried to shim the rails, with recessed valves, when running studs? Another set of "Shorter" rods would be easiest, but we're only talking .008 from where they currently run.
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Minniappolas made an old tractor engine like that, the cylinder/head bolted onto the block kinda how a 2 stroke engine cylinder does.
I've never had an issue with valvetrain but I also have valve recession checked/cut as needed to ensure that. If you cut too much off the head I could see there being an issue where the pushrod is too long but I would imagine that has to be an ungodly amount as they have quite a bit of adjustment. I think the most we had to take off one set was 0.021" or so, I don't remember but it was on the verge of being in spec. This also wasn't a build like yours, it was a stock work truck that towed a 20ft enclosed daily for a local construction company.
All of the 2 stroke engines I have experience with have a removable head and cylinder which alleviates the concern above of "how do you machine it properly if the head is non-removable".
I didn't think .020" shaved off this obviously stock and uncut head looked to bad on valve depth. Especially when it checked .015" warped with a straight edge from just free standing for a few years..
Anyways, my main local machinist, one who cut our rods and picked up that .002" over-bore in these blocks back in "Piston Rocking" pages, just sent me some video of finish cutting a duramax head today. Guess he's ready to step up to the plate again..
I'd actually forgotten how many hours he has into these engines. But his surface cut looked smooooth..
Also Dustin found a set of low mile LML heads in our scraps still bolted to a block. Besides the injector bores, are those worthwhile candidates? No idea on the valvetrain differences...
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Anyways, my main local machinist, one who cut our rods and picked up that .002" over-bore in these blocks back in "Piston Rocking" pages, just sent me some video of finish cutting a duramax head today. Guess he's ready to step up to the plate again..
I'd actually forgotten how many hours he has into these engines. But his surface cut looked smooooth..
Also Dustin found a set of low mile LML heads in our scraps still bolted to a block. Besides the injector bores, are those worthwhile candidates? No idea on the valvetrain differences...
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Machinist was texting me pictures and video of freshly cut Duramax heads yesterday.
Not sure if he's applying for the job, or trying to seduce me..
Either way, he'd better hide that set before I role in there tomorrow.
He's gonna chit when he sees this crap I'm dropping off....
Not sure if he's applying for the job, or trying to seduce me..
Either way, he'd better hide that set before I role in there tomorrow.
He's gonna chit when he sees this crap I'm dropping off....
If you can machine out the injector bores, the LML heads will work. There are no valvetrain changes.
Down here on the river, all of our tools still use flint cutting technology. Freebies, and broken leftovers from our Indian ancestors who ran head shops here 1500 years ago..Might be worth while coming up 33 a ways to better machine shop.
These heads are heading to Logan within the hour. Any further up 33, it starts getting a bit Ritzy for my county budget...
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Heads dropped off. Said he'd see what can do with em and give me a call. I forgot all the valves and retainers out of the spare castings. But we both agreed, lets stick with the well seasoned valves, that have already passed the 1900F sustained flow testing.
He didn't have a block fire ring cutter. But he does have a jig on the mill to ring 6Leaker heads. Said those guys run 035 welding wire with good success. If I want to try it, he's willing to prep em..
He didn't have a block fire ring cutter. But he does have a jig on the mill to ring 6Leaker heads. Said those guys run 035 welding wire with good success. If I want to try it, he's willing to prep em..
Mike Humphrey. He is who tore down and hot tanked these spares some years back. Also did the rod work, and final balance of all the heavy spinning pieces. Life long machinist and Logan native. It's either been him or Oaks since I started playing again.
Ah wait, did use Fowler to do the old LLY block. Guess they are gone now.
Ah wait, did use Fowler to do the old LLY block. Guess they are gone now.
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I told Mike to consider that assembled pair as scraps. And to let me know if he finds anything weird with these castings. Easier to find another donor than spend much time doing anything more than a good surface.
I have a spare set of used heads from an LBZ and there is guy out here that I got them from that has more. Obviously I would go inspect them personally first.