Nissan 370Z Forum - Feeler: CP Pistons, Medium Comp, 10:1

Nissan 370Z Forum (http://www.the370z.com/)

- Group Buys (http://www.the370z.com/group-buys/)

- - Feeler: CP Pistons, Medium Comp, 10:1 (http://www.the370z.com/group-buys/73580-feeler-cp-pistons-medium-comp-10-1-a.html)

Yup we can get them any time. I *might* grab a set or two extra for stock... But I am leaning more towards stocking a custom piston for hr/VHR compatibility

Quote:

Originally Posted by phunk (Post 2586078)

Yup we can get them any time. I *might* grab a set or two extra for stock... But I am leaning more towards stocking a custom piston for hr/VHR compatibility

Good deal. Between homeowners insurance, Xmas, two birthdays and property tax, there's no way in hell I need to be dropping a grand right now on car parts I won't be using for 25k miles.

I know some people are in a hurry (maybe) to get these pistons, but I'm with Chuck. If nobody's dying to get the pistons, would it make sense to push the GB back into January?

Not speaking for the crowd, but it would definitely help me out considering the holidays (big $$$ expenses) are here and whatnot.

Quote:

Originally Posted by phunk (Post 2584825)

BTW I am curious if you guys are interested in this.

I have thought about constructing pistons that would be compatible with both VHR and HR cylinder heads. This means anyone who wants to make the change immediately or down the road is clear to go and will not have to do the bottom end again.

I already discussed this with CP and the conclusions we came to was that this was most likely very possible. We have to compare the valve angles between the HR and VHR cylinder heads and do a little math... but by adding some well planned exhaust valve reliefs to the pistons we could probably have a piston for the VHR bottom end with HR or VHR heads. Some research also has to be done to determine if this will or will not change the CR between one head and the other.

I was concerned about if you guys would care for this or not. I wasnt sure if people would feel there is a compromise in the pistons design to accommodate cylinder heads that they are not running. But this would sure be a lot easier on me for stocking in the future. On top of that, I am currently leaning more towards HR heads for my build, but I am not ready to commit to them yet... but I want to start my bottom end build!

I,for one, won't be going to HR heads. I remember reading an article on the differences between the VHR and the HR and one of the things that they pointed out was that the HR head had "sharper" edges in the combustion chamber compared to the VHR. This, although it might not seem that big of a deal, could potentially cause hot spot in the combustion chamber... not exactly what you want in a high compression boosted engine.

Phunk, do you think you could work in a group buy for CP rods also? Maybe get a bit of a cheaper price from CP for the combo? Or free coating?

You know that is a great idea. Anyone who wants pistons is going to want rods also. The only negative to that is having to pay for both at once.

I will inquire Friday if they are open, otherwise Monday. I am going to talk about pricing with them again because I think we should get a little better.

As for holding off until after holidays, I am extremely open to that. I have so much custom work to finish for my new engine that I won't need the pistons and rods for a few months.

It's really up to you guys. I was trying to push this forward to get cosmo taken care of, but if we need to wait and he has to go solo for now, it is what it is.

We have to get to the point of solid communication with one another to come to a compromise on timing.. So speak up everyone!

1. phunk ; 100% in, any time before March.
2. Chuck33079
3. GaleForce
4. tibal
5. cosmogirl (maybe)
6. OldBoy
7. djtodd
8. OMGWTFBBQ

Listen guys I cant wait another 4 weeks for the group buy and then another 4-5 weeks for them to be built. I am sorry but really don't have a problem paying for a custom set now. Please let me know what your planning to do so I can move forward with my build and again I am sorry..
Happy Holidays

I'm in no particular hurry at the moment either. After the first of the year would work just fine for me. I have a spare engine in the garage anyway if mine does go tits up.

As for the hr/vhr question, I really don't have any realistic plans to do an hr head swap, so I'd prefer normal vhr pistons.

Quote:

Originally Posted by cosmogirl (Post 2586429)

I don't want any of this stuff, but I'm with you. Do what you gotta do. People should jump in on YOUR buy right now.
Do what you gotta do, can't wait to see it up and running again, real tune at Z1, and awesome numbers

I would be open for a group buy myself. I haven't been on the forums much lately and this sounds great. I was looking for a set of 10:1 pistons. I already have a short block stripped with crank assembled, just need pistons, rods, plus a few other things.

I'm in no rush for this, so whenever.

Phunk, any news on a price for the pistons and rods combo?

Sorry it has been a hectic week taking delivery of a new CNC. I will get information for you about this this week!

Phunk, forgive my noobness but does this have any good gains for NA? Cause from what i saw, most of the names on the GB list is already on FI

These would be solely for a FI application due to the lowered compression ratio.

noooob question, as ive never looked into built engines before.... but is that price per piston, or for all 6 lol and whats a typical shop charge for installs on engine parts like this being the work involved