Thread: engine question for you expiernced techs/machinest/smart people

As i get ready to build my gtp out of the boring 3.4 set up i bought some nice new toys.... XP hot cam with modded retainers, 705 push rods, 875 lifters, machined double rollermaster all new gaskets, machined oil pump cover, zzp headers and the little stuff like plugs and wires..... so heres my question..... I was thinking about buying a bare set of heads for cheap money. I want to know what i have to do to run 1.9 rockers with the xp cam.. or would that be over kill.... also while the heads are bare i want to buy a new set of exhaust/intake valves.... so what do you guys suggest for valve sizes and what to have the machine shop do so i can safely run the xp with the 1.9 rockers

Are you serious?

Afaik you can't

Yes? Which is why I asked the question

The highest you can go with a cam is 1.8 which is still a crazy amount of lift.

So its pretty much not doable and even if it is its overkill

not worth your time or effort to run anything like this. just forget you thought about it.

Fair enough

What about valve sizes?

you have two choices: stock, or manley valves. that's it.

if you're really going to attempt building a sick ass set of heads, be ready to spend $3000.

Well I got a set of bare heads for 40 bucks.... work with a guy that has a machine shop that can do all the custom work
.. so that's why I asked what is need to do so I can run rockers with my xp cam

If your just doing the heads and not porting them then just stick with the stock valves. But if your stock heads aren't cracked then its not really worth the trouble. I do recommend having the magnafluxed, a 3 angle valve job and new seals, springs, and retainers. and you can have the machine shop mill the valve guide to allow for .600 lift. And paint them while they are off.

I have brand new seals, locks and retainers if you haven't bought them already.

I recommend crow cam 105s with the xp can, comp cam 105s had a bad batch and springs were breaking. Hell since your going with the double roller then you could do 130s but if you don't plan to change your stock shift points then its worth it.

To run rockers with the xp can't be done on stock heads, you'll need to have the valve guides mill to allow for more lift. .600 lift is most common. Buy you'll only be able to do 1.7s with that and you'd be better off with stock rockers to be honest.

I have 130 springs and retainers already... I'll just have the heads cleaned and do a valve job.

It's not a bad idea to get the bare heads for $40 and have a mild port job done to them. There's a stickie on here somewhere about porting our heads.

I think I'll do that..

Make sure you look at the write up though and make sure the machinist does too, people have made the mistake of gasket matching which is NOT what you want to do.

Ya I'll show him the write up