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Cylinder head thickness

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Brosky

Brosky

Great Pumpkin
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I probably should have done this first, but couldn't get to the computer after I spotted the deal.

I just bought a spare head for my 74 TR6 from I guy that I know well on ebay. The head has been CBN milled and pressure tested. The new thickness of the head is 3.39. Is that within the good height range? I don't really want to get into shortening pushrods or having 10-1 compression, but I guess that it's a bit late to think of that.

Anyone know the starting specs on the stock head?

Tom, you out there? I know that yours is going to the machine shop. Can you have it measured before and after, or even your after?

Bill, I think that you just had yours done. Any thoughts on this?
 
Whoa, looks like 10/1 compression to me.

See this is all Tom and Bill's fault. Now I'm gonna have to start accumulating parts for the day when everything comes out and gets rebuilt. There's no way I would put this on without doing the rings and bearings and no way that I'd do that without pulling the engine and line boring it and polishing the crank, and, and, and........

It never ends.............but that's why it's called a hobby.

I'll get this one all ready to go with new seats, valve seals and springs and spend the next year getting parts for the bottom end.

Here's a picture of the deck surface.
 
Paul,

I'm running 10:1 with a mild polishing job.. No problems, just gotta watch that timing.

And it diesels like nobodies business... its all part of the ... patina.
 
Shannon, don't want to shoot you down but you have to know what it came off of and year. You also have measure volume of both head and block to get an accurate compression. Ask Ted. He made me do all that. I ended up with a head off a GT6 from him for my 9.5 to 1
 
DNK,

No I didn't do all that so it's an estimate at best.

But! With that being said Richard Good is the one that did my head work, so if it's not 10:1, I'd say it'd pretty close.
 
Paul,

I have Richard's specs for a guide but we are going to cc the head to be certain and then decided to only go to 9.5:1 instead of 10:1. There are several reasons and the bottom line is that I just don't need it and I want Shirley to be able to drive it without having to deal with dieseling or what gas to buy.

Oh, I called a different printer yesterday. I think my other source is going to loose my business over that other thing. And I will dimension the other project and get that sent out. I had a massive design project going that was somewhat overwhelming.
 
I see Premium Fuel in your future...
karnak.jpg
 
I thought everybody already used premium?
 
The use of premium in a stock Triumph is a waste of money. The only time premium is of value is when the compression is raised considerably. The power obtained from regular is the same as premium. I used to run premium in my 1970 454 Vette because it had 10.25:1 CR. My TR6 is set at 9.5:1, somewhat higher than stock, thus I run premium. It knocks if I don't.
 
That engine has never seen anything but premium. This is just going in the collection for a wishful project someday.
 
Paul,

You could take a cc or 2 out of the combustion chamber with a die grinder when you cc them to lower the compression a bit. Plus smoothing the edges will help with the run on. Triumph guys are lucky, look at the combustion chamber on an MG head some time-lots of sharp and pointy bits to get hot and let the engine run on and on and on...

Erik
 
I plan on using E-85 in my blown 354 Hemi when I get the $$$ to finish the project. At 40 cents per gallon less it makes sense to at least try it.

I've got the engine set at 8 to 1 static with about 8 lbs of boost.
 
While E-85 may be a good idea for using a mostly renewable energy, it really won't save you much money as you will be filling up more often. E-85 doesn't have the same amount of energy/gallon as gasoline and your mileage per tank will be less than with gasoline. Most research has shown that with the current cost structure, your dollars per mile will be right about equal between E-85 and gasoline.

Its a good eco friendly move, but relly won't save you much money.

Eldebrock is making shiny new E-85 specific carburettors though.
 
Erik,

I'll bring it by for a look see after I get it.
 
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