I have one question about my Ls/vtec build. How much of a risk am I taking using Ctr pistons for Ls/vtec? Other than having to use high octane fuel and p2v what other problems could arise? My setup is b16a head with stock valve train and itr cams, itr intake manifold, port matched tb, ctr full floating pistons, gsp forged rods, crank has been micro polished, rotating assembly has been balanced also just need to know whatever might be in store. Thanks.

 

Sounds like you named all the risks. If you already have the short assembled, take the time to check P2V clearance and modify as needed. The static compression ratio will be quite high with those pistons which will require tuning and maybe even higher octane fuels.

For your cylinder head, I recommend at least upgrading your springs and retainers reduce any chance of float, especially if you plan on revving beyond 8,000 rpms. Hit me up via PM, I got a few good deals.

 

I have definitely looked into upgraded the springs and retainers along with valves in order to eventually use a stage 2 cam of some variety just not sure which yet. As for valve float is this something I should be concerned with even during break in period. I plan on getting it tuned just have to drive it around to get my money up. She will not be dogged in this time. At the moment everything is at the machine shop but as soon as it comes back I will check p2v clearance.

 

Have you considered breaking in your engine with a break in oil such as Torco TBO? You can take care of the entire break in procedure in one dyno tune session, rather than risking injury to engine by driving around untuned.

 

I've never even heard of that. So running that oil during a dyno tune right after the motor is built will basically break it in during those couple of pulls? How does that not risk anything with a brand new motor?

 

Some people will tell you that ctr pistons are very heavy and create a very high cr. And they will tell u that these things will cause premature wear and short engine life. I am not one of those people. I think that with a good reliable tune and a consistent reliable fuel. You will be just fine. Only things u have to worry about are the things u stated and possibly detonation caused by heat accumulation on the very sharp tip of the cast piston. So maintaining a good oil pressure and working oil squirters would be important to me personally.

 

breaking in a new engine is nothing new. it is preferred by many people.

 

Thanks for all the help guys once i get everything machined and done ill post up some pictures for your viewing pleasure.

 

Get a tune

 

Yeah I know. I just had everything sent the machine shop. The dude who had the block before me apparently put assembly lube behind the main bearings and there was no clearance. Glad I decided not to trust him and pulled the bottom end apart.

 

Hey guys one more question for anyone willing to throw out an answer. I am looking at dual valve springs to purchase and was wondering if I should upgrade my retainers as well? If I purchase the springs I will be running stage 2 cams instead of the ITR cams currently in the head. I am trying to build the head to compensate for the high static compression ratio due to my use of ctr pistons and everything I have seen has said the higher the compression the bigger the cam you need. Any insight will help. My block will be going together this weekend so i'll post up some pictures if anyone wants, thanks alot.

 

I've got the motor all together and everything torqued down, but the crank won't turn. Are the pistons hitting the head? I'm not sure what to do at this point.

 

did you rotate the bottom end before you put the head on?