PINTO CAR CLUB of AMERICA
Shiny is Good! => It's all about the Turbo... => Topic started by: tintmaster on December 11, 2013, 06:45:50 PM
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So I have been told that now the new thing to is use a N/A D-port head instead of a Turbo head. They said because the turbo head has too many hot cold cycles and cracks. Plus the N/A has smaller cc, can unshroud the valves and open the chamber to make better flame travel. I was told heads from '86-90, mustang or ranger.
I have a good turbo head I took off a running motor. I still need to get a turbo block and crank or a whole short block for my build.
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If your turbo head usable with no cracks I would go ahead and use it, the difference between them is very minor, also the only difference in the turbo block is the oil drain back provision and the crank is no different from non turbo.
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From what I have gathered finding a turbo head without a crack is rare. I have one in mine right through the exhaust seat. My car sees limited use, but it has not been an issue.
These heads seem to have the ability to get real hot. The exhaust seat in mine actually deformed and then the valve took the shape of the seat. I just did my "poor man's valve job" lapping the daylights out of the seat until it was corrected with an old valve. Then I chucked another valve in a drill press and cleaned the surface with a file. Later I went back and relapped the two cleaned surfaces together.
Some may cry "ghetto mechanics" but it cost me nothing, the valves seal really well. Is the seat width a lot larger than normal? It sure is and I'm also sure very effective at heat transfer. Did the margin on the valve get thin? Yes it did, for a little while. I used the same file on the sharp edge to thicken and round the valve edge. As long as the valve didn't get any smaller than the seat width it is fine. In fact I increased the total seat diameter and made the valve smaller. Both are helpful to increasing flow.
Yes, there is doing things the right way, but with these heads that is no guarantee. On the other hand sometimes you have to be like the Joe Petroni character ("I can't hear a thing..., there's too much noise") in the movie "Airport," where you throw away the manual and do what it take to get the job done.
Tom
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If you use a N/a heartshaped chamber head you will need to port the head to remove the heart shaped so it resembles a turbo head more you will also need to change the exhaust valves due to them being different.
Usually most people only use N/a head cause they are less likely to crack. I have a oval port/d-chamber that came off my bobcat originally that I plan to port and install big valves in and use on my turbo motor when its time to upgrade it more.
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Yeah Bigt, thats what Bo does with them. My buddy had 1 done earlier this. The cost was over 2K, included everything though. Just not sure I want to spend that much when I can get an Esslinger aluminum D-port head for around that.
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bo does an awesome job but I plan on doing all the port work myself on my extra head and have a shop install the larger valves. Should cut the costs a ton and be good for a street/strip car if it was just for all out race id go essy or Volvo head.
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'Yes, there is doing things the right way, but with these heads that is no guarantee. On the other hand sometimes you have to be like the Joe Petroni character ("I can't hear a thing..., there's too much noise") in the movie "Airport," where you throw away the manual and do what it take to get the job done.'
I have that page in my book as well, and I go there in 15 seconds if I have to. I prefer to do the accepted thing but many times it's just not justified, at least the extra cost or time is not. I've been known to change just one cam bearing in head, or only grind exhausts and not intakes, lapped only, or other non-accepted practice MANY times and never suffered for it yet. In fact, can't kill the cars. I lap in using a drill motor, been told a hundred times it can't work, luckily the car cannot hear.
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That what being a gearhead is all about. Or you could do like the Brit's and drive it till it breaks and then you know what was wrong with it. The choice is up to each individual.
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Why cant you use a drill to lap valves. that like saying you can only port a head with a file
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If you have a turbo head with no cracks or only minor ones, It might be a good idea to have seats put in so it doesn't crack or get worse.
1.) If you use a N/a heartshaped chamber head you will need to port the head to remove the heart shaped so it resembles a turbo head more
2.) you will also need to change the exhaust valves due to them being different.
3.) Usually most people only use N/a head cause they are less likely to crack. I have a oval port/d-chamber that came off my bobcat originally that I plan to port and install big valves in and use on my turbo motor when its time to upgrade it more.
1.) I don't think it's necessary to do that, but leaving the head alone will raise compression by about half a point on an otherwise stock 2.3T and 2.3Ts are already octane sensitive.
2.) I agree; the turbo exhaust valves are made of Nimonic 80 and outlive all the hot parts around them.
3.) I don't know that NA heads are less likely to crack, but they are definitely less likely to be cracked and are easier to find.
My $0.02
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FYI, one reason not to use drill to lap valves is that the grinding compound has to be relocated around a lot to not start grinding grooves in the seat. Ever watch someone lap while repeatedly lifting the lapping tool again and again? What that's doing. With drill you just lift the valve a LOT. Like as quick as you can. Even so it may groove a small amount. Guess what? That grooving, usually considered as bad work, actually seals better as the edges interlock more to seal like solvent testing (provided guides are tight like they should be). AND, once the engine gets good and hot, the miniscule grooves actually flow around to meld together and out flat when red hot. Take a running motor apart after a bit and chase down any grooves you knew to previously be there, they will be gone. Similar to the grind valve seat at 45 degrees and the valve at 44 1/2, the difference in angle forces a fitting to each other under red hot conditions. The very small edge contact point at first flows ever so slightly to mate up better.
You DO try to avoid grooving on valves that are not hardened all the way through; only like surface hardened like nitriding (Japanese stuff like Honda comes to mind). These Pinto valves will be hard all the way through. You can't regrind surface hardened valves, the coating gets removed and what's underneath is super soft steel, seat eats valve like lightning then. Dead in maybe 5K miles.