A15 Piston Options

[Kirden]

Well, with all the B210/210s showing up lately, maybe it's time we got a little more A-series info over here. I'm looking for piston options to achieve 8.2-8.7:1 CR in the A15. Growing up around budget hondas and wanting boost, the first thing I thought of was Vitaras, so here is the info I found:

 

Using the information from summitracing:
http://www.summitracing.com/parts/uem-3414h-1-0mm/overview/

I'm coming up with somewhere around 7.2:1 with a 0.8mm headgasket thickness for vitara pistons. (This could be remedied by decking the head, but vitaras are only available in 75-76mm, so if your cylinders need a bore you're SOL.)

Using the same calculator and 1mm deck clearance with the A15 piston information from summit gets me 9.46:1 using 1.2mm head gasket thickness.

http://www.summitracing.com/parts/uem-9083-1-0mm/overview/

 

That's all copied over from my post on the 1200 siteexcept for what is in parenthesis. I've also contacted a custom piston builder, but with the mild goals I have for my build, I prefer not to spend a small fortune on the slugs. So now I'm looking for 76.5-77mm slugs that will get me to my ~8.5:1 CR goal.

 

The specs I requested from the forged piston company are:

76.5mm bore

19mm pin diameter (press fit)

30mm compression height

12cc dish (stock is 6.5cc)

two valve reliefs

1.5, 1.5, 4mm ring gaps.

 

These are basicly stock pistons .5mm over. With a 1mm squished height head gasket I should be right in my range. I'll update if I get a price back.

 

 

[Dime Dave]

Try looking up the specifications for the Sentra GA16DE pistons, years '90-'94.

 

Stock Bore - 76mm

Wrist pin - 19mm

pin height - 29.5mm (as best as I can determine)

[Kirden]

Thanks, I'll take a look. If the dish is in the 6-10 range that will probably work.

[ggzilla]

Stock compression ratio is 8.5, except for some round-port A15 engines which are 8.9

[Kirden]

D'oh yea, I think you mentioned that on the 1200 forum :P

 

I got mixed up because the 1200 wiki says 9:1, a thread I found said just under 9.5:1 and others are saying 8.5:1. Maybe there are differences between US and Non-US engines? According to the engine setup and the notched Nissan rocker cover, I have an A15 from a C120 or C22, not a US A15 from a B310.

[Kirden]

Sharing the info I gathered. Got an email back from Venolia about having some forged pistons made. $92 each, no rings or pins for 76-78mm pistons. If you send in an old piston they will match the pin and ring gaps exactly and you can get stock replacement rings and pins. The price isn't bad for forged, but I'll stick with stock till they break. That's $400 I get to spend on other goodies :)

[afracer]

Sorry to revive an old thread, another option is to have a look at 1.4 tsi pistons (vw, Audi, etc). 76.5 mm available, 19mm pins, 29mm compression height. The only thing I'm unsure of is dish cc.