I have a b18a1 that I'm about to do the LS-VTEC head swap on. I got some b16 PCTX pistons that are already attached to some Gsr rods from a buddy. Would this combo be good in a turbo setup?

 

If so, what should I bring the compression ratio back up to and should I use a duel fuel pump with bigger injectors

 

wrong rods they're 137.9 vs the 137 of the ls, the ls rods are one of it's big weak points tho so it would not be an upgrade in any way.

 

B18c1 is 134mm... So if I use the gsr crank and the GSR rods with PCTX pistons in a ls motor with b18c1 head then boost it to get back up to 12/1 compression ratio. And go with bigger injectors. Would I have many problems

 

 

sure but are you doing all the measuring and checking clearances? if you're paying some one that will be a lot of money for all that work, you'd be better off buying forged components. They're still stock rods/pistons 12:1 is iffy, it's like some ppl try to use the CTR piston for a 13+

 

TReyWilliamsIII,

Actual GSR (B18C1) rod length is 137.922mm (5.430"). The Wiki post you have referenced is for a B16A showing a 77.4mm stroke... that is the incorrect engine/stroke combination... and thus, your 134mm rod length is incorrect.

The B18C1 crankshaft stroke is 87.2mm

If you use the GSR crankshaft and rods, you may have to modify the PCT pistons in order for the pin end to fit. Trouble is, the combination you have suggested will create an effective compression ratio of over 14:1 AND the piston will stick out of the deck of the block. This reduces your quench area, and coupled with forced induction, will make for a combination that is challenging to tune effectively on pump gas. A better choice is to use the ITR style piston with a shorter compression height and less dome volume to create a more realistic compression ratio, yet still a powerful and responsive forced induction engine.

 

I already have the b16 PCTX pistons on the GSR rods... So your saying the GSR block on a 1997 teg type r US has longer rods than a 1990 ls b18a1? If so than the Pistons I'm trying to use along with the rods and crank would make the Pistons hit the head.... B16 PCTX pistons are taller as well. Sounds like when the rods stretch the Pistons will hit the heads. So your saying itr pistons would be better?

 

Or are you saying don't do forced induction. And leave it naturally aspirated

 

So are these wrong too... Where can I go to get the correct measurements?

 

Pretty sure you cant use gsr rods on a ls crank because its the big end is skinnier, and also is the bearings for said rods. youll have alot more side to side motion.

 

All ls and b20s use the same rod and crank.

 

The big end of the B18C1 (GSR) rod is narrower than the B18B1/B20 rod so that one doesn't mix them up. They would be WAY sloppy from side to side. Your smart phone screen shots above have the LS rod technically correct with a rod length of 5.394" (137mm). However, the info on the B18C1 rod is still inaccurate: The actual length is as I stated above: 5.433" is the factory stock rod length and standard aftermarket rods vary in length from 5.430" to 5.433". The B16A is the shortest at 5.290" (134.37mm), but B16A block deck height is way shorter than the B18 and B20 variants.

Part of the problem with the CTR pistons is the install height or compression height. Most "B" series pistons have a compression height of 1.181" or 30mm. The stock ITR piston is a little bit taller at 30.23mm (.009" closer to the deck surface) and the CTR (PCT) pistons are WAY taller at 30.73mm (.029" taller - coming out of the deck .018" on a virgin block. Some aftermarket PCT copies may be slightly different, so measuring your particular piston will tell the tale.

 

So... By your math. B18c1 crank has a 87.2 mm stroke. With a b18c1 rod that has a 37.7mm length and a piston that is .030" higher than a normal piston... I should be safe because the ls crank 89mm stroke with a 37 mm ls rod and normal piston hight is acually taller...

 

Did I mention I'm using a b18c1 head as well...

 

Like BSwapped said, you can do it but if you're planning to turbo it down the road, you're better off buying forged ones. If you're building an N/A, that seems like a good combo, just make sure you have the match crank/connecting rods and check clearances.

 

You've made up your mind I think, just "clay it" if you actually do to see, but there's a very good chance you'll have PTV contact tho or too close for comfort.

At the end of the day you could have 15:1 C/R but you're still on the stock rods, it will be by no means reliable and once you step over the 12:5.1 you're off pump gas. An s300 would be needed too no shitty "crome" or a chip

 

I'm using demon2 with Neptune. I've talked to a lot of people using CTR pistons in the race world. It's a common high compression piston used in the all motor build. May have to add a thicker head gasket to lower the compression a little if it's 14:1 or more. Should be at 180 to 210 horse power from what theirs has produced with close to same build on e85.

 

This thread is dead but op missed the point of non pump gas so it doesn't really matter alone with the claying bit.

 

Hello everyone, I am in the process of building up a b18c1 engine that will be dropped into my 1991 CRXsi. I have been reading thread after thread on how to go about this build and what things did and did not work for others. all the information can be a bit overwhelming and (as often stated) with b series engines you can start with the same engine type as a hundred people and build it a hundred different was, I comes down to what you the builder wants and how deep your pockets are.

With all of that said this is what I want to do, I want a fun reliable smooth running engine, yet a little more powerful than the stock daily driver.


I want to do a NA b18, here is my question can I run P3 or P30's with my stock GSR rods?


And if I can run those pistons on a stock block will I have to change anything in my valve train?

ps. if you know the name or member of a thread that has talked about this please let me know the title so i can read about it