B20 Pistons for Low Compression Setup

[KaedenKy]

I found out not too long ago -that piston offsets are not always used. I will have to check with the seller to find out.

When I spoke to both ross and diamond, they said they by default sold with no off set. You had to specifically request it.

Until my rental house sells, about a year from now, I won't be buying anything custom. Mainly just parts hording till then.

[Whitefinish]

What does it mean, the piston offset ?
Should 3 be produced with a center hole slightly to left, and 3 to the right?

[KLZE Porsche]

What does it mean, the piston offset ?
Should 3 be produced with a center hole slightly to left, and 3 to the right?

That is how it would be normally. Yes -the piston offset is the pin center displacement from the piston centerline.

[KLZE Porsche]

I got word back from the seller today and he said there is no offset -as I suspected. These look like a very good alternative to uber expensive custom pistons.

[dammitcam]

So what does this mean lol

[KLZE Porsche]

So what does this mean lol

Cheap heavy duty pistons with factory coatings and better than OEM KL rings. -->8 pistons with ceramic coating for under $500 delivered -or 6 custom pistons from brand XXX for near $1000!

[dammitcam]

Cheap heavy duty pistons with factory coatings and better than OEM KL rings. -->8 pistons with ceramic coating for under $500 delivered -or 6 custom pistons from brand XXX for near $1000!

I need brands and part numbers, so I can get some prices for us

[SBPGT]

$699 for the right pistons made for the KL.

No longer in business but some pat numbers and prices...
http://www.importperformanceparts.ne...ons_mazda.html

I would guess Wesico and Ross still can make our pistons, but they don't list them anymore. Maybe they'll do some bulk buys for us?

[dammitcam]

$699 for the right pistons made for the KL.

No longer in business but some pat numbers and prices...
http://www.importperformanceparts.ne...ons_mazda.html

I would guess Wesico and Ross still can make our pistons, but they don't list them anymore. Maybe they'll do some bulk buys for us?

From what it appears is that those are only sets of 3 pistons not 6 and uncoated with no rings :/ I priced them out through Wiseco and they said roughly 150$ for a single piston and the wrist pin retainer and something else was discontinued

[dammitcam]

85mm is .020 over for a KL if I am correct? That is just about perfect for an overbore rebuild without going too far.

Yes. From what everyone has said (I know you are an old timer in these parts and are aware) but it's best not to bore these engines

[KLZE Porsche]

Yes. From what everyone has said (I know you are an old timer in these parts and are aware) but it's best not to bore these engines

Yes -a long time back when there was a craze to attempt to make a 2.7L KL with .040 over bore -they kept developing cracks. So with a lot of the feedback gotten over the years from different bores and builds -it was determined to be risky to go past .020 over. I also have the original RR engine block and it was bored .040 over. It had cylinder cracks so now it has become a good welding or mock-up jig.

[dammitcam]

Well let me know what you figure out I can help you get a cheapish set to mock up or whatever you need lol

[KLZE Porsche]

Well let me know what you figure out I can help you get a cheapish set to mock up or whatever you need lol

As soon as I sell an item I am attempting to sell -I will get a couple of sets on order. If people here wanted to do some sort if bulk buy -it could be worked out so that 3 sets are purchased by two individuals and each takes 6 pistons. This would reduce the cost significantly. I was also told that I could get a large quantity discount -which then again would also reduce the cost.

But a lot of testing would need to be done first. As soon as I get a couple of sets -I will do actual high accuracy measurements and do the math to select the correct rod and deck milling combination -and what CR it will produce. I will also need to fit a piston with clay to check for valve clearance.

So far it looks like a 123mm rod with 21mm pin is the correct choice. But of course this is only speculation until I have a piston set in-hand for measurements.

[KLZE Porsche]

I finally ran into some cash and decided to splurge on the Honda pistons to see what is what. As soon as I have measured once, measured twice and done the calculations -I will post up some photos and some numbers/specs. Maybe we can make this happen.

[KLZE Porsche]

I did a few calculations today. There is .031" difference in compression height (Honda being .031" taller). So -for rods I have two choices so far. The first is Millenia "S" rods (my favored choice at the moment). To use them it would require moving the Big End (BE) by .031" -which is do-able. But the wrist pin is correct and so nothing else would need to be done.

Second choice is Toyota Hilux 2.4L rods which are the perfect length, perfect BE -but pineye is 24mm -which means they would need to be re-bushed to 21mm. But they can be gotten in 4130 "H" beams -and so that could be a plus.

I am not going with any crazy build at the moment and so I am thinking I will just stick with the Milli "S" rods because for one I can get them cheaper and for two -moving the BE by .031" is likely to be cheaper than re-bushing the Toyota rods.

The pistons appear to be hard annodized and have a special coating (probably ceramic) on the top and above the top ring. They are floating wrist pin type and so they have spiral locks. They have good rings.

I will post some pics later.

Probe rods are 137.82mm or (5.426") So the target length would be 137mm (5.395") 136mm would work with deck milling. Big end Probe is 56-56.015mm. (2.2047-2.2053").

Toyota Hilux 2.4L rod length is 135mm -which could possibly also work with deck milling. 2mm is approximately .079" which isn't a lot. It is just a little over 1/16".

But the big end on the Hilux rod is 56mm -right on target!