Tony D

Don't pull the head, use an inspection camera through the plugs. You pull the head, it's just another batch of parts.

You can get anything you want made in China these days...

Re: "Tiny Combustion Chambers" Remember the volume of the OSG, optimized for 2.8/3.0's was 35cc's. If you work at it, reeeeeally carefully, you can make them 40cc's. That's it. You can do the math from there what CR is available from what displacement using simple flat-tops.

I wouldn't think a race engine would use flat tops. Ours weren't by a long shot! Welded N42, and a dome. 13.75:1 CR. There's 'racing' and there's 'Racing'...

That indeed is the head, same photos. For the price, I'd put it on the wall to look at....upset the guy sold it for that, as my offer was near there for 'wall art'! Too bad the contact information is not available, and the listing has been removed... I would have liked to talk to the owner.

^^^Or sponsoring a trophy in his name for one of the events. In 2004 Group Z of SoCal started the People's Choice car show event at ZCON.

It goes to the same reason they don't have the head welded. Forged slugs are now $600+, and with a matched top....

65 psi at idle?

That wasn't stated up front, duplicity can drag it out forever. Yeah that's full advance. How much does it "need" with the closed chamber on it?

What are we looking at here, a flooded exhaust turbine and failed CHRA Bearings? It looks like the impeller blades ate something. #1 cause for new turbo fails is not replacing the line as it's all coked up. I don't know that I'd put a filter in that line as that restriction can starve the bearings... what type of "filter" was it that was installed? It is possible to overwhelm the seals if you oversupply the turbo with oil. I mean, exactly what is the failure mode here?

Much more money going that way than coming this way...

Never put loops in water lines, they hold water bubbles and block flow. There is a slope for best thermal siphon after shutdown. There is a pressure differential moving it through when running. After shutdown operation is far more critical to prolonging turbo CHRA life than what it does when running and having copious amounts of oil blown through it.

Is there a register to hold the seal in at all? It appears there is.... Grind back from the break around 5-10 mm a tapered feathered edge, leave a step where the break occurs. It helps to do this with like a 36 grit disc. Clean everything scrupulously. Install the seal with a dusting of PAM cooking oil on it. Build up the area around the break and seal with DEVCON ALUMINUM PUTTY. It's a structural epoxy that you can machine, tap, and work just like metal once cured. Yeah, you could use JB Weld, but I have a tub of this stuff laying around and have used it for years as it doesn't run on vertical surfaces. If you have a dust cap, then after it's cured, file it and use a long piece of sandpaper to make it nice and round again. Pull out your seal, clean it off with some brake cleaner to remove the oil.... Clean out the new cavity you made, and put in some sealant like Loctite RC608 Cylindrical Parts Locker, or Permatex Avation High-Tack, either in the recess or on the seal OD and reinstall. Shouldn't take long at all and no disassembly required.

^^^^ And there you have it. Took someone 3 years to dig up a Manga and scan a photo, but there it is.

That's nothing I'd give my wife to go get groceries with.. Basically a stock build then, and even then using controlled timing. If you can't run proper spark advance at only 9.5 on regular, much less CA91 Octane....I'd call that a 'pingmonster'! For the stated claim of the engine to be a 'racer' I think my characterization is spot on why they O-Ringed it! It kept blowing head gaskets and it was cheaper to o-ring it than have it welded.... and pistons are cheap, change them out every couple of races anyway, right? For my money, I'd pick a different head, or simply do it right. If I can make 375 turbocharged horsepower on an N42 that in the good old days could run on CA87 up to 12 psi.... I think that's not a bad testimony to how well an N42 or any L-Head will work when you get the right chamber in there in terms of detonation resistance.

Thanks for that Mike. It looks like I will miss this by three days, not leaving Saigon here until the 5 or 6th and my prebought ticket stateside is the 10th (for Mom and Dad's Funeral.) Miles, any links to articles or obits would be appreciated. The search engine here in Uncle Ho's Worker's Paradise aren't helping me find much. current information.

Nope, I don't think it's misleading at all. You can do it right, or take half measures. Pistons and rings are cheap, right?

Shite. RIP JC

But that's why you soak them in water: to make the old hard asbestos gaskets conformable...

Weld it and get your combustion chamber mirrored in the piston tops to give the CR you want. Everybody welds up that open chamber N42. It's just pingmonster if you don't.

quit overthinking it and just do it == it's interim by your own statements so what difference does it make? I don't know how much clearer this can be other than the three times it's been stated already.

Throttle Shaft Bushings are an easy fix. If that stops one from reclaiming a carb...well, lets just say our definition of 'mechanic' differs widely! That said, the ability to read the manual and the service brochures out there really help understand what was going on at the time. There are those who want to know, and those who don't want to be bothered and settle for what "works" and not what's optimised for the situation. What's 'easiest' always gets you in the running, you can always hope for someone to have mechanical troubles and grab a spot on the podium. But those who don't chase 'easy' usually are the ones people are hoping break down so they have a spot in the sun....some day!

It's an L-Engine with an 89mm bore. That's all you know, and that's all anybody can know.

Given it's an unwelded N42 and open chamber with signs of detonation damage in several cylinders, my thoughts are as old-school builds go you O-Ringed the cylinders to keep head gaskets lasting through a race. This is a detonation monster, and has peaky, uncontrolled cylinder pressures so they o-ringed it to keep the gaskets in, rather than welding the chambers and getting a quench-head faster-burning, less detonation-prone setup.

^^^just a hint, the time to visit your local Z-Club is BEFORE you spend all the money!