[DiceX]

I know the j30a1 doesn't have much potential but I wanted to try and see if thus worked. The compression ratio on a j30a1 is 9.4/1 while the newer j30 was 10.0/1.

I've been told I can swap them, I want some feedback, does anything else need to be changed, I will be getting new pistons fir j30a5 from npr with piston rings.

Thx

 

[matthell226]

What pistons will work in the J30a1 without modification to the cylinder sleeve or the connecting rod? I am looking for a piston that will accommodate the J32a2 valves. I know I can have the valve reliefs enlarged on the stock piston but if there is a optional piston with the large valve reliefs that raises compression than it is an option.

 

[WHEEELMAN]

What pistons will work in the J30a1 without modification to the cylinder sleeve or the connecting rod? I am looking for a piston that will accommodate the J32a2 valves. I know I can have the valve reliefs enlarged on the stock piston but if there is a optional piston with the large valve reliefs that raises compression than it is an option.

What are you trying to do exactly. Throw the J32A2 heads onto the J30A1?

 

[matthell226]

What are you trying to do exactly. Throw the J32A2 heads onto the J30A1?

Yes, the goal is to mount the j32a2 heads on the j30a1 block taking advantage of the hotter cam and larger valves. Correct me if I am wrong but if the cam is notched I should be able to use the j32a2 heads with the distributor. Based on what I have read in the forums this combination will work but I need to either have the valve reliefs enlarged in the stock pistons or use an alternative piston.

 

[matthell226]

I found this post in a different forum:
K20A2 forged pistons (9.0:1 CR) can be used in our J30A1 block who are looking to reinforce it for future boost potential and save some money instead of totally custom order. Both bore size identical = 3.388" (86mm)

What happens to Compression with J32a2 heads and K20A2 pistons? What about the location of the wrist pins and are the wrist pins the same size between the K20A2 pistons and J30A1 rods? What about the valve reliefs in the K20A2 pistons?

 

[oraclem19]

definitely could see a mild turbo thread here. Want some help with that? Just use )or make) drop cr pistons, will get you your space, port the heads a little maybe, get an exhaust, turbo, and custom fit kit on there, and I have the electronics over here.

 

[matthell226]

definitely could see a mild turbo thread here. Want some help with that? Just use )or make) drop cr pistons, will get you your space, port the heads a little maybe, get an exhaust, turbo, and custom fit kit on there, and I have the electronics over here.

So far I have purchased: E-management blue along with tool support, GT35R water cooled turbo, water to air inter cooler, J32A2 plenum, J32A2 intake, J32A2 heads, and a ported J32A2 68mm throttle body. I want to run 8-10 lbs of boost but I still need to figure out the engine internals and the injectors to use. What are cr pistons?

 

[matthell226]

So far I have purchased: E-management blue along with tool support, GT35R water cooled turbo, water to air inter cooler, J32A2 plenum, J32A2 intake, J32A2 heads, and a ported J32A2 68mm throttle body. I want to run 8-10 lbs of boost but I still need to figure out the engine internals and the injectors to use. What are cr pistons?

There is a place in California that modifies pistons. They have a list of upgrades they can do to the factory piston including enlarging the valve relief. Below is the companies name, phone number if interested.
ATTN: DPR Racing / Dan Paramore Racing
1611 E. Sandison St.
Wilmington, CA 90744
Telephone: 310-293-3186

 

[WHEEELMAN]

Have someone clay the J32A2 heads on the J30A1, the intake valve may clear the piston.


You could also just use J35A3 heads with the CL-s cams on top of the J30A1. That combination works. Only difference in the A2 vs A3 head is the Intake Valve is 1mm smaller in the A3 head.

 

[DiceX]

If he was to add j32a2 heads to a j30a1, if I remember correctly he can use j30a4/5 pistons from the 7th gen accord to help with the valve clearance. They are same size just higher compression. Idk the comparison between the k20a2 pistons and their compression. If someone has more feedback on that it would be great.

 

[J356thgen]

if your just looking for more power I wouldn't start with the pistons,you can buy ful rails/injectors now and opening up the exhaust really helps thes engines

 

[berserkasaurus]

the j30a4 crank is forged but it wont fit without mods its too short on the pully side

 

[Roorobb45]

Y’all seem to be pretty decent with you k20a2 and J30A knowledge so let me ask you this. I’m looking for a set of 86mm forged pistons for boost and I’m trying to push a ratio of 9.4:1 on this j30 but I can’t get any compression knowledge because everywhere just sells them for k20a2’s so I was wondering if someone could give me a piston part# or something to help me out.