jinxedz

iTrader: (5)

Took the stock heads off to replace the lifters during my cam swap and was wondering how I should go about cleaning them up ...

Pieces of the head gasket are still on the block and the head ... should I just lightly sand these off and call it a day, or send the heads out to get professioanlly cleaned? maybe even mill them a bit?

thanks

PREDATOR-Z

Either that or just send them to a shop, have them cleaned (shaved .003>.005) and reassembled with new springs and valve seals). This of course if you have a cam that would allow a slight shave without affecting PTV. (if that is the case you should flycut anyways)

jinxedz

iTrader: (5)

Thanks for the suggestions guys.



It is a TR230 Cam with a Patriot Gold Spring kit. I dont think there should be any PTV issues.

Studytime

iTrader: (15)

I vote for a .030" mill. Patrick G.'s experience before says that'll fit and give you a 62cc chamber.

With a thin gasket, that'll give you ~11.1:1 compression and will make that 230/224 cam even torquier.

Ben T.

brad8266

iTrader: (23)

I would also take em to a shop and have them hot tanked and shaved, that way they will be clean and 100% flat.

As for the block, a green scrtch pad will work.

jinxedz

iTrader: (5)

Is .030 a little over board? I was thinking .010 ... but then again, thats only b/c ive seen that number thrown around a lot and it sounds on the safer side.

Ill be using stock GM gaskets.

thanks again guys,

PREDATOR-Z

.005 = ~ 1cc
.030 mill = 6 cc
That is a 60cc chamber, add a thin gasket like .040 and that is like a 57cc chamber. Overboard on PTV and SCR/DCR

.020 mill with stock gasket will be fine and plenty clearance.

WS6nJAX

iTrader: (207)

i agree with the .020 mill and stocker gasket. i went .030 with the f-13 and i just had to tear the top-end back off and flycut. wish i had just done it the first time.

Studytime

iTrader: (15)

How do you figure? Using .006" per CC you knock off 5 cc's of combustion space for a total of 66.67-5 = 61.67, with will be roughly 62cc. That with a .042" gasket will not be overboard on an otherwise stock motor.

That puts you at around 11.1 SCR and 8.55 DCR.

PTV will still be within safe street limits. Remember, this cam has no advance ground in.

Ben T.

Studytime

iTrader: (15)

Also, TEA states the same thing I just did. A .030" mill for a 62cc chamber.

Look at "Specs, Notes:" under the first item listed on this page;

http://totalengineairflow.com/products/gmhead/gmls1/

I would assume that TEA uses an accurate burret to CC their heads.

Ben T.

brad8266

iTrader: (23)

You are using .006 and predator used .005 per cc. And then you posted .0075 from TEA to prove it, lol. Thats 3 different answers.

Studytime

iTrader: (15)

Also, refer to this thread back from 2002;

https://ls1tech.com/forums/showthrea...highlight=2.02

Ben T.

Studytime

iTrader: (15)

Well, Brad in response to your comment let me just say that ALL THREE are different than what Predator used.

Also, TEA's number and my number (final chamber volume) are very close. Where did you get .0075" from?

Ben T.

PREDATOR-Z

60.67 cc you're correct LS1 is 66.67.
But that is why I put ~ sign in front of .005
Better mill, measure chamber and mill again if necessary to achieve desired chamber volume.
Regarding PTV, are you judging that by chamber size or valve drop reduction?
Also for .006 values what are you using? TR230/224 are 281/275

brad8266

iTrader: (23)

Actually predator used .005. I apologize, I miscalculated what TEA says, its more like .0065

cowboysfan

so, back to the origin question. if you are worried about milling your heads then use the green pad. (scoth prite) on heads and block. if you can get something with a straight edge or even glass to check heads that should work as well.

Studytime

iTrader: (15)

The advertised values I was using was 283* (If I remember correctly). That's what came off of the cam doctor, and I feel is more accurate then adding XX degrees to duration at .050".

I was judging PTV clearance by valve drop reduction taking into account if more material was removed off the deck of the heads AND a larger valve was used on Patrick G's car, then a smaller valve and a thicker head deck should clear. That seems like perfectly sound logic to me.

If I was running a TR230, I would mill .030" and use a .042" head gasket even after everything that's been discussed. I've assisted in the build of a TR230 62cc CNC LS6 combination that worked very well.

Ben T.

PREDATOR-Z

[img] http://ourworld.cs.com/jrp98ls1/tr230.jpg [/img]
So are the values I gave. actualy they are a bit less, I rounded of
A 62 cc (.010) mill LS6 has more valve drop than a .030 milled LS1.
I had milled some 241s before, but I can't remember what was the 1cc relative to mill.
Anycase no 100% argument on my part, I would still measure to be sure. Of course you know me, I'm talking about .080/.100 margins of safety.

jinxedz

iTrader: (5)

Thanks for all the input so far

I took the heads to a machine shop to clean up, put the new dbl springs in, and possibly port mildly.

Considering I will be using stock GM Gaskets, I am thinking milling either .010 or .020 and calling it a day

Studytime

iTrader: (15)

That was meant in reference to the TR230 with 11.1 SCR- not valve/piston clearance in any way.

I agree, measure with a degree wheel and know for sure.

jinxedz, if you're trying to decide between a .020" or .010"- go with the .020" mill. Compression is your friend. It'll even idle better (smoother) if you can get the compression up some.

Ben T.