I have my cly head off the block and want to know how much I can machine off? I have a machine shop that will do it but I have to tell them how much. I don't think it has been machined before. I would like to get a little more power for hills. Thank you Bob Diederich MTFCA 22350
I milled .125" (1/8") off a couple heads.
My friend said he could notice a little more power...I didn't see a difference.
Mine cracked after a year or so.
I wouldn't bother.
I have seen 1/4 milled off, you need to shorten head bolts.
I took .125 off and used domed pistons.
Bob D. -- Since you don't know whether the head and/or block have been milled before, you should use balls of modeling clay on the tops of the pistons to determine how much clearance is there. Like Gary, I have used domed pistons and milled a low head .125, but not before checking the clearance. I put about 5 balls of clay on each piston, to see where the closest point is. After that, you can use just one per piston at that closest point.
BTW, Using the domed pistons and milled head, I noticed quite a difference in power, similar to using a high-compression aluminum head. (No dyno involved, just seat of the pants experience.)
I'm not sure that milling the head without using the domed pistons would make much difference, but it might help a little.
Hello, I.am the Bob that posted the message about milling the head if any one has any thoughts on the subject either neg or pos please post. I have the head off but if there is no change in performance I'am not sure it will be worth the bother. Thanks Bob
Bob, Use the money that you are going to pay for milling the head and buy new domed pistons. Its a little more money but lots more power than just milling the head. And you get fresh pistons with tight ring glands. And of course new rings. You will like the power increase. Scott
.125 is the minimum to mill off a stock head to make it worth the effort and SHOULD make a noticble difference in any Model T , how could in not! 1/4 is about max off a stock head.
Milling the model T head to raise compression is about the single most important serious performance improvement (and a easy one),one can make in stock car . I live in a city of hills and heavy city traffic..Geting a little more peppy off the line and a good head start for the hills is needed. My last Runabout a 24,,with iron pistons..I milled off 1/8" .The car ran cooler,idled smoother,started quicker.added 2 -3 more MPG overall and many of the hills I had to shift into low I was able to pull in high gear! Remember the fuel wasn't to good and lower compression was needed back then but many cars had compression in 5.2- 5.5 range at the time.And Fuel is better as far as knocking.
Some places have trouble milling these old flat heads because they can' t just bolt them up in the new jigs set up for more popular modern engines, 2 machine shops I tried couldn't/wouldn't do it.The head(scrap test head)chattered..The one shop local I found that worked on vintage cars for a high end restore/dealer did it,and actually lightly threaded a head bolt hole on each end of head..(I barely noticed it) to hold it down right. It was 200.00 bucks..Its not a fast process and setting up took time I;/m sure.You may find cheaper .
I'd mill an iron head down before I spend on an Aluminum head...Iron/steel and aluminum don't like each other and it's nice to keep as much period metal on the car if you can!
Can you tell us how much they are doing it for? so we have a ballpark for whats a normal price for such thing? Thankyou!
Hi, Nathan -- I've been trying to answer your question for 3 days now. Thanks, Chris!!!
I've had some iron heads milled 1/8" at two different shops. The charge was $60 at one and $100 at the other. Those are Arkansas prices, so they should be about that in SC, ballpark anyway.
$45 around here for mine to get milled.
If you want power buy a Z head. Huge difference !
I milled a low head for my car to 680 CCs if I remember right. Look it up on that club in Co. that does all the dinoing. It made a bit of difference but the Z head was amazing.
Note that a milled low head gave me only 4.2 to 1 compression and an unmilled Z Head gives you 5.8 to 1 but the power comes from the much better combustion chamber design. WELL WORTH THE $$
BUT,Jerry!! David said iron/steel and aluminum don't like each other. (Dave you forgot copper) aaand it's nice to keep as much period metal as you can (I know, that second one's out there alittle) Please don't tell my T's, they love their Z heads Over 8 years on the one car But you know me most likily not alot of miles on that car...
Mike, it might be your imagination that most new cars have cast iron blocks with aluminum heads
I just put a P head on my car (along with a new engine).
It certainly has more power than the old engine with a Waukesha Ricardo head.
Yeah, Mike I've seen your car sitting with grass growing up around it!
Yard art?