Proper Aluminum Head Maintenance

[lun40119]

I have already picked up on the differences in lash characteristics, hot and cold, and the obvious, antisieze and such...........but what about the seasoning of the head over the first season. Should I remove the heads, and have the seats cut. I have heard that as they heat cycle over the first year, they move quite abit. Just wanted some opinions on this matter. Thanks in advance

[Awesome Bill]

that is nossense and was started because of bad production valve jobs. Years ago and still every once in a while we were having heads come back in for freshen up and when we would touch the seat, only ½ or even ¼ of the seats would make contact off the valve guide. Even the valves were slightly bent and would require .003-.006 removal of material to clean up. People think just because the head is brand new its perfect. We don't live in a perfect world. When valve seat concentricity is off from the beginning and you do not know it, then when you freshen up or have to repair something that is broken, you find these things out. Then the machine shop says stuipid like must of been settling in the casting. If this had any chance of being true, then the big three and every other car manufacture with new engines being run and even ito lawn mowers, outboard etc, would need to be pulled down. Correct and accurate machine work is the key. No you do not have to remove your heads to do anything. If they are flat, and the valve job was done correctly, it will be the same deal when it comes off. We are cycling engines in for freshen up and we find the heads to be almost perfect with the ones where the valve springs were maintained. The ones with poor valve springs or were left to run high rpm and low seat pressure look bad. Beat up so to speak. So take your time have everything new rechecked before you use it or you could loose it. hope this helps

[want-a-be]

Sooo,,,what your saying is that blocks and heads don't season. And that when it seems like they have seasoned that is was due to bad machining of the manufacturer?? So the main journals don't move around and the seats don't either?? Man...I'm really learning some new stuff here. I hang on your every post there Bill so I can learn new ways to make HP.

[Awesome Bill]

I am not saying blocks don't settle, if you want to call them that. With hot cold, hot cold, hold cold, there are some moelicular changes, but nothing that will hurt you if you use proper machining and clearencing. The honing procedure, the valve job, the valve train, the induction system is where all the power is made that really makes a ton if difference. I am a firm believer if all the metal is the same, its all going to do the same thing. We make allowances for aluminum and steel as a mixed pair. Valve seats, and guides have a little tigher press fit. .002 sometimes mores because of the expansion rate of steel verses aluminum. But most of our problems are with brand new untested stuff. Give me a block that has run a year and I know its good. Same with crank and rods, cam and lifters, valve train etc. Keep it simple and conservative and you will find you make the most power for the buck. Hope this helps.

[want-a-be]

now we agree

[Awesome Bill]

glad for all that!

[Bacon104]

I am a firm believer if all the metal is the same, its all going to do the same thing.

Thats why large CAT diesel engines that make enough torque to lift Rosie O'donnel use main caps made from the same Iron as the rest of the block. (Not billet of a different material)

[Awesome Bill]

Indy engines don't use billet material either along with a ton of other engines. Billet caps are pretty much usless and we only do it because it sounds good. It offers nothing to an engine in my opinion and is a waste of money. I have a Dart Iron Eagle we have just finished for a Comp Car and we cut every thing we could off the block for weight after it was lightened. 55mm roller bearings cut all the bellhousing material off we could motor mount studs gone everything. We took the billet steel caps off and put aluminum on, saved, almost 20lbs!. 10,000 rpm and the engine purrs like a bumble bee. We took it back apart and checked everything and its perfect. 3.70 honda journal 39lb crank, Giannone aluminum rods, pistons look like they stayed to long on the cnc! etc. very lightweight with 14° steel heads that flow better than the SBX pro stock from CFE. made 1040hp with Engler Injection! So the aluminum main bearings look like they were never run. So why do we need billet?