I'm hopefully going to buy pistons within the next month or so and had been planning to go with the domed aluminum. The engine will be going into a '24 tudor sedan, a member of the heavyweight club. After seeing the threads about slowing down on hills and many references to car weight I'm having second thoughts.
Like most of you I have a budget. But, with a desire to travel at a reasonable speed (high gear up typical hills) am I being short-sighted trying to save myself $350 by going with domed pistons with a standard high head? Should I really plan on getting a Z-head?
If I go with the domed pistons now, can I change out the pistons easily with the engine in the car?
Yes, you can change out the pistons in the car even with a 3 dip pan.If you have upgraded to a 4 dip pan,which if you aint,it is a good thing,changing out the pistons will be a piece of cake.
I have 060 over domed pistons with a stock head (surfaced for clean up only) in a oak bodied panel which is pretty heavy. Stock rear end ratio with a warford & ruxtell. I can run 45 on flat ground which is legal for short runs on the interstate (Crossing the Mississippi River at St Louis). Works for me. Nelson
Mike, I had the same dilemma about a year ago. I posted the same question on the forum and was told that the dome pistons will only raise the compression ratio about a half point. You could always change them out later I guess if you wanted to add a high compression head. What I did was go with the regular pistons then several months later I purchased a high compression head. there is a guy that advertises them in the MTFCA magazine for $300 I believe. I could never reach the guy and ended up getting one of the vendors to match his advertised price for one.
Pistons are easy enough to change with the engine installed just pull the Radiator/head/inspection cover but you might want to hone the block which is a bit messy. As mentioned in other threads the clearance can be an issue... I have done this operation on a car that had too little room for it's new pistons.
My humble opinion is that you read the tech info presented by the blokes from Tulsa... they talk about the chamber shape being quite important. I reckon you could make up your mind from there. It's only money anyway:P
Buy the head and regular pistons. Then you only have to change them (pistons or head ) once.
Great, thanks to all for your input. My engine is out of the car (which is currently a pile of rusted metal) and I just had the block & head resurfaced, rebabitted, crank ground/polished, and cylinders and valves honed. This will be the best opportunity to get it right. Glad to hear though that I could still change them out without needing to pull the engine.
My T money is my "play" money so I've got to pick and choose carefully. I'll research the testing results, but I'm now leaning on going with flat pistons and standard head now, and after the car is on the road save up and buy the Z-head.
Nelson- I'm not expecting too many problems on the flat ground. How does your T do pulling the hills? Are you always in low gear?
Domed pistons raised my compression ratio from 50 to 75 psi. The engine was rebuilt at the same time and some of the raise was from a shaved head and block top.
The difference in top speed was more pronounced. It went from 40 to 70 mph and the T was never opened up full, due to stopping again or likely rolling over from the quick steering or a blowout.
James, that's a pretty significant increase in compression and speed. These are the experiences that cause me to go back and forth on this decision.
Any other '23-'25 tudor sedan owners out there? What do you guys have in your engine and how does your car do on average hills?
I live in Maine near the coast where it is relatively flat, but we do have plenty of decent hills around. Maybe I'm making too much of this...
James, you were able to do 70 MPH with the Z head? Wow!
The best I could do with a Z head, Stipe 280 cam, high volume intake and straight-thru NH was 60 MPH, and that was downhill....
(BTW, I'll never do that again!!!!! )
James, I just realised that you said "domed pistons", not "Z head"....
Read twice, post once......sorry
Bob, you are correct this time, no Z head, but I do have one that I may try on another engine.
70 mph in a T? I know we see these fiqures all the time and some do it regular and aint had no trouble.And for that I am thankfull.But aint no way this fat boy is going no 70 in a T.I aint got what it takes to do it.
Mike I have never been in any big hills. Just some mo. ozark hills. Never had to go to low if I could get a run. If I turn a corner & encounter a hill then I will be in low. Depending on the grade & length of the hill. I do not think I have to use low abnormably. Nelson