need your help honda tech dudes, cant find no info on puttin ctr pistons in a stock jdm b18c itr block, only things i find are outtin these in b16 or gsr blocked but nothing about a jdm itr spec r block, all i want to know what has to b done in order to put these in!!! i know theyre both 81mm .

 

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OEM PCT pistons require you to modify the rod pin end or piston pin boss width... some aftermarket CTR style pistons already have this modification addressed... but either way, the compression ratio gets awfully high.

 

thats fine because thats what im aiming for a high compression all motor set up but i just needed to know what and exactly has to be modified and cut, what ctr style piston brand would fit he stock itr rods?

 

Check out the RS Machine/YCP offerings. They might be what you're looking for. You are aware that you're probably going down a road where you might not be able to run pump gas, right?

 

yessir i know ive been thinking of running e85 tbh but this idea was mentioned and given to me by my uncle. but i cannot find no info on puttin these on a itr block or any specs or anythings that has to b done to put these in. ive heard of it being done but i want to know exactly was has to be done. of course later on im thinkin of goin straight skunk2 head package.

 

The bigger your cams, the more static compression you generally can get away with.

It's been done before for sure, especially back in the 90s and early 2000s... it was pushing your luck then and making the window between power and knock pretty tight. Unfortunately, gas is not what it was even just back 10 years ago. It's only going to get worse too. Engine formulas that worked 10-15-20 years ago just simply don't anymore.

 

If the machine work is done properly this combination is fine and works quite well. We did a build for a guy a while back that was a B18C5 block/head with PCTs, King race bearings, OEM oil pump, water pump, timing belt, all OEM gaskets, Skunk2 pro manifold, AEM fuel rail/reg, AEM 340 pump, RC 310s, Skunk2 Tuner1, Skunk2 Alpha springs/retainers, PLM Toda rep header, 3" test pipe, Skunk2 76mm exhaust, S4C w/ Mfactory diff, Stage 3 clutch/Fidanza Flywheel. The setup made 210 hp and 139 tq and ran absolutely fine on Sunoco 93 pump. It could have made Even more steam with more injector and some E85, but we set a conservative timing map and gave the customer what they wanted; a high comp pump gas motor that was reliable and made good power. We succeeded on both fronts by the way as last I heard the engine turned 50k and it's 4th consecutive year racing circuits without a single failure to speak of.
So bottom line, yes it can be done with a little machine work, but make sure a reputable shop does the work. (I.E. someone who has done this modification before.) Even if you have to ship your rods to get them done right it's worth it over going to someone local who doesn't know what they're doing. Also do yourself a favor and get the whole setup balanced at assembly time. That is critical to longevity for these high RPM screamers. Use a factory head gasket and don't mill the head or block any and you will be totally fine on pump gas with a good tune. (Another area never to skimp is the tune!) Your compression will be high but not race engine high; your talking around12.5-13:1 when your done. (Static) Depending on your cam choice your dynamic compression will vary. A great cam for 12-13:1 1.6-1.8L engines is the Skunk2 Pro1. I've seen this cam profile make excellent power in a number of different setup ups. The build I mentioned earlier would probably have eclipsed 215-220 HP with Pro1s as opposed to the Tuner cams. (Although the Tuners do work very well too.)
Also take into consideration header choice. This combination is going to need to breath out as much as it breathes in so the exhaust is crucial as well. Don't go too big, like a big tube Hytech or SMSP as you won't have the displacement for that. Depending on what you want to do; a nice PLM Ramhorn or PowerDriven reverse megaphone header would be a good choice for a toy/track build because it would make great top end, however for a daily street car I'd suggest something like an RMF Narrow for the ground clearance and combination of top end and low end power. Ofcourse the old stand by of the 4-1 JDM 2.5" and replicas always fit well and make good power and the TriY designs are always a good choice for an all around setup in my opinion. Whatever you do, when it's done get it tuned right by a reputable tuner and it will be a fun reliable setup. After all it's a Honda Good luck!

 

all I'm tryna do for now is this till later
put in ctr pistons to boost up the compression, 340cc injectors sk2 alpha headers , port matched 70mm tb run it open headers for now which was recommended or 3in pipin, the questions I just basically had is if I put these in what has to b done. I already got answered that some after market pistons comes with the adjustments to use them with my stock rods which is a plus. What I'm worried about is does tdc mark change cause they're no longer flat type pistons or what. Basically I'm just tryn to put these in a stock jdm b18c spec r and drive wit it till later on when I do the whole sk2 head package

 

Changing pistons does not move Tdc.

 

ok ty bro that's what I needed to know I think I got everything I need. I learned a lot, I learned they sell ctr after market pistons that are already made for its rods and its a direct fit.

 

I believe that's what I pointed to in my first reply to your post ��

Seriously though, I have almost 100k on my RS Machine ITR clones, no issues here. Just be aware, they are not quite the same and you really should measure them yourself (or have your machinist do it for you)

 

ok bro thanks alot, have you ever seen or heard of anyone just running ctr pistons in a stock jdm itr spec r with just bolt ons?

 

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May I ask, why PCT pistons ? I'm doing a 81.5 GSR but I'm going with Wiseco 12.5:1. Is this a budget high compression kind of thing? I've never known anyone personally to run this set up

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