MaxPow3r

iTrader: (2)

It's a debate that folks will get into...

Is it NECESSARY to resurface aluminum heads when taking them off, and re-gasketing.

I'm not talking about a burned headgasket replacement, just taking the heads off to swap lifters.

I'm getting ready to pull my heads and front cover to replace the AFM/DoD cam with an upgraded cam, plus do LS7 lifters, pushrods and new springs. I will definitely clean up the head surface, and make sure any old gasket material is removed...

...but is it NECESSARY to resurface? I'm saying it isn't, as long as no work is being done to the heads (porting, etc). I can see resurfacing if the heads were worked and you may be worried about the surface getting nicked or scratched during the proces...

Thoughts?

thunderstruck507

iTrader: (18)

If the engine has been ran, I resurface the heads. Well worth the $40 peace of mind when the other option is having to redo it all over again.

Aluminum is too easy to warp under heat/cooling for me to chance it. My dad is a mechanic and at his shop if an aluminum head comes off, it gets surfaced. Period.

MaxPow3r

iTrader: (2)

I'd be really surpsied if the heads are warped. I can see resurfacing to ensure a perfect RA...

I guess the other question is what percentage of high(er) HP motors have pulled the heads for lifters, etc and NOT resurfaced?

DavidGXP

iTrader: (14)

I would say no. Make sure you put the head back on the same deck it came off of, and use a little gasket remover, with a sharp flat razer to the clean both surfaces, then rinse with brake clean.

I have pulled my heads off a few times, and have never had an issue with doing the above. If you were to swap heads or mix them up, then yes.

If you are really worried about milling.. then take the heads to a shop and have the decks checked.

chrisfrost

iTrader: (8)

Spend $20 and buy You're own straight-edge ,,,,,,,it's a pretty simple process to check cyl heads for flatness ,,,,,,,,,,,,best thing to do is put a light behind the head/straight-edge ,,,it will allow You to see even the smallest discrepencies in flatness . I would say if cleaned correctly even an aluminum head with some miles as long as it has'nt been over-heated would not generally need resurfaced but You never know unless You check ,,,,,,,,so any material iron/aluminum cyl head should be checked to be sure whenever removed for any reason .

cabel1

iTrader: (3)

There is no reason to resurface every time they are off.

87silverbullet

iTrader: (11)

I worked at the dealer and I have been owning my own shop for a couple of years now and I bought my own straight edge. I don't like the idea of resurfacing them everytime they are off if there is no issue.

Over heating-yes
Blown gasket- I check it and send it out if need be or replace it

If i am just changing the lifters or something and nothing with the heads is causing an issue, I just clean them up and check them and they get bolted back on.

NemeSS

iTrader: (127)

Yes. Every time. It's cheap insurance. If anything else fails after. Warped heads will be eliminated. If something happens to go wrong. It will bother me to reinstall non milled heads with many miles with new head
gaskets. I would never do it for someones car I've been paid to work on. Less chance of failure IMO

mebuildit

Well if you resurface the heads? what about the block? I think a straight edge to check is just fine. Do you see top fuel doing that after every run? Not the same thing but still, those go thru more than we can ever put thru our engines.

Plus everytime you resurface one, you are taking away material every time.

midevil1

iTrader: (17)

HOLY CRAP!! Don't resurface your heads every time they are removed. Is this a REAL thread?? Real Tech's know and are trained to mill only a warped or scarred head.

If you are concerned with some sort of failure AFTER YOU ARE done with the job, then you have no business working on BIGBOY stuff. You want to redirect your attention to the nearest LEGO set..

driver56

I work at a machine shop building heads and we recommend surfacing heads every time they come off, ESPECIALLY aluminum heads. I've seen it too many times where someone tries to get away with not surfacing them and it ends up costing them twice the gaskets and labor. What's cheaper: two sets of head gaskets, two sets of TTY head bolts, and twice your time, OR a $40 surface job and doing the work once?

NemeSS

iTrader: (127)

It may be possible to get away without ever resurfacing the head. Is it ok? sure. Needed? Sometimes. I will have it done and reccomend every time. Not only have i worked on big boy stuff, but have built from ground up. Machine work to assembly. Please see comment below. This is fact. Ive seen same thing as a machinist.

This!
I will second this motion. Being both a machinist and a install tech. I will agree with the machinist on this one. I also machined/assembled engines and heads for a living once.
So i see from your point of view.

midevil1

iTrader: (17)

Sure, just trying to keep the doors open by selling labor. I have all the machines to do my work in the barn. That doesn't mean I fire up the mill every time I tear down a motor.

What happens too the guy who is experimenting with cam shafts and what not? He ends up with NO PTV clearance and 13 to 1 compression.??

Milling heads shrouds the valves and kills power. If it is for cleaning up a imperfection, than it must be done.

I will tell you what.. I have a car sitting here with a CNC 598 FORD with Twin 91's and we have pulled the heads without milling 4 times and it see's 36psi on the big end. Makes a consistent 2600whp has Jesel Custom shaft rockers that cost as much as a crate LS3. $8500.00 Block. $3000.00 Cola Crank. BRP Titanium Rods. ETC, ETC..The point being we are dealing with a 150K car and we don't mill the heads for it??? If We thought we were gonna hurt ANYTHING on that motor. We would take the precaution.

Buy a straight edge and a MAG Light and check it yourself. Go see a machinist when you blow up the motor.

xxrillixx

iTrader: (118)

I dont resurface heads unless they need to be done... but I always replace the head gaskets.

Only people I hear saying to resurface the heads EVERYTIME are machine shop owners (or their family members). Seems odd to me that you would resurface the head... but not the block. In my experience, if one was truely warped, usually the other is too.

midevil1

iTrader: (17)

^^^^smart man listen too him.

NemeSS

iTrader: (127)

I hear ya, but comparing high dollar race stuff to basic oe and catalog or speed shops is not the same. The oe ls castings are not as thick or as rigid as say a pair of allan jackson billet heads, or a set of big chiefs or some race cfe's,etc. Im not trying to argue with you.
Some of these heads will need a resurface upon reinstallation. Preferably for a better seal with the mls gaskets, even the higher mile aftermarket castings can benefit from a resurfacing. just hard to compare a ported set of stock 243s with 10k miles to a top fuel drag race engine. 95% of the stuff that came thru the shop was typical street/strip car guy stuff. So i guess i speak from my point of view.

gregrob

iTrader: (8)

Needlessly resurfacing them every time they are off is absolutely absurd.

01ssreda4

iTrader: (96)

This thread is dumb for so many reasons. I have never seen so many apples to oranges comparisons on one page in my life. There is no one right answer for the OPs question. I've always resurfaced, but that does not mean I think it was mandatory every time. I also don't work on 5xx c.i. race engines or school buses or B52s or Sherman tanks.

driver56

If you've got the money and time (more money) to do the job twice then don't cut them. Will it work out for you? Maybe. If it doesn't, would you wish you had surfaced them? Absolutely. But whatever..... it's up to the car owner to decide.

midevil1

iTrader: (17)

Not arguing either. I wouldn't resurface the worn out 317's on my HD unless they showed to be untrue. Head gasket technology has come A LONG WAY in the past 10 years. Even small imperfections can be mended with the gaskets of today.

Nicks and deep or moderate scratches to the sealing surface should be addressed, but if none of these are present and the straight edge is true, then WHY mill??