NISMO is now producing forged pistons and rods for the 350 with a 8.5:1 compression ratio. Does anyone have these? Heard a rumor about 350z's not being able to handle forged internals due to the makeup of the sleeves and the aluminum block. Can this be confirmed?

 

NISMO's internals are fairly overpriced for what they offer. Buying aftermarket pistons and rods is much more cost effective, and allows you to select custom sizes and CR ratios. For instance, I'd personally choose 9:1 static CR for a turbo VQ.

As for the rumor about forged internals and the makeup of the sleeves -- I haven't heard this rumor yet. I do know that this problem exists for Honda's H22A and F20C engines, which used FRM (fiber-reinforced metallic) sleeves that were in some way incompatible with forged pistons. The pistons would leave heavy scrapes in the cylinder wall. The only solution was to resleeve the block in ductile iron. I haven't heard anyone say anything about this regarding the VQ, and I know there are a handful of built motors running out there.

 

I heard that the forged internals will be a fair bit harder than the stock piston sleeves - and this may lead to premature wear over the stock pistons....

 

I made a post about this in FI forums and this topic has been discussed before. They are apparently made by an aftermarket forged piston/rod manufacturer and rebadged as Nismo. They are indeed overpriced for the badging.

If you are interested, please contact the person that ran the group buy for forged internals in the FI forums.

If you have trouble finding him, please PM me, I've spoken to him before. Good luck.

 

hmm why would nismo make (well not really make but rebadge and sell) the forged internals especially with a lower compression ratio, unless they have a plan to release a FI kit?

 

so i can get forged internals for the VQ without getting resleeved? is the crank already forged?

 

This is the type of stuff I am interested in, and would like to read more about. Have my new block ,waiting for pistons and rods. What is the correct way to go about building a sick engine for the 350z . I am starting from scratch so i want to do it right and not have to pull it apart at a later date ,when I am trying to get more HP from the motor. Would sleeving a new block be the way to go ? Plan on going TT APS, a lot cheaper to mod the motor when it is apart. Anyone have a little insight on this.

Thanks Ken

 

a) yes the forged pistons can be used with the OEM sleeves. SGP, Z1 , boulder and many many others have proven this.
The builder should follow the bore clearance specs as indicated by the piston manufacturer. If the orginal OEM sleeves are used a .020 overbore (with a TQ palte during bore) is recommended , but , no more than .02 over.....

b) rumor has it that the OEM sleeves and crank are good for ~800bhp. Only time will tell if this in really true. But in the short history of VQ35 builds it appears to be somewhat true, since most builders to date use the OEM crank and sleeves with FI builds at >600rwhp.

c) if you wanted a bulletproof block , with targets >800bhp , you would want to consider either AEBS t-sleeves or Darton Mid- sleeves. These effectively "close" the block deck. This upgrade costs about ~$2k (parts and labor).

If you have more questions SGP , Z1 , bolder Nissan etc. can probalby shed some more light.

 

Yeah sleve it just in case!