286110 vs 286210 Piston Performance ?

17.6:1 is would be accurate if compared vs the '94-95 piston with no protrusion difference, but there are too many variables to just make an assumption if you want accurate information.
 
Smokem said:
17.6:1 is would be accurate if compared vs the '94-95 piston with no protrusion difference, but there are too many variables to just make an assumption if you want accurate information.
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I think I have already hijacked this kids thread enough, I'll start another thread and ask more questions. Im more confused now than before. :poke:
 
Tate said:
He was talking about the 1.00mm oversize piston at 17.6.
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Correct, if you kept protrusion consistent, and replaced a 1st Gen intercooled piston with a 1mm oversize 286210 piston the compression would be 17.6:1.
 
Hmm. On my pulling engine I was stuck at 30* until I put the thin washers in, then it didn't show symptoms of missing the piston until I got to 36*.
 
Non IC 1st Gen 286210: 59.12mm diameter bowl, 43.2cc bowl volume

IC 1st Gen : 54mm, 44.5cc

286110: 64mm, 47.1cc

94-95: 52.1mm, 45.4cc

96-97: 52.0mm, 41.5cc

STORM: 51.29mm, 44.5cc

Comp ratio is dependent on a few variables: protrusion, HG thickness, valve reliefs, ect.. Also keep in mind not all these pistons have the same comp height.

Timing/nozzle protusion: Approx .04* per .001"
 
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Not that I didn't believe people here that I do have quite a bit of faith in, but curiosity was getting the best of me, so I got out a shortblock,
degree wheel, and dial indicator.

First off, since the injector is on about a 18* angle, .040 of injector washer change is actually .038 of vertical change.

Results change with crankshaft angle.

40*-.038= 39*

30*-.038= 28.5*

20*-.038= 18*

10*-.038= 4*

OP, I think it would be safe to say that with thin washers and .040 off your head, 3-4 degrees more timing could be expected if you are figuring in the 20-25* range.

There is also a piston that has a 60mm bowl, and is referred to as 18.5:1. I have not cc'd one.
 
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I don't see how changing washer thickness is effecting timing?? It still popping off at the same time, the nozzle is just further down or higher up. It's not making it pop any sooner in the crank rotation?? What am I missing here?
 
Ghostman said:
I don't see how changing washer thickness is effecting timing?? It still popping off at the same time, the nozzle is just further down or higher up. It's not making it pop any sooner in the crank rotation?? What am I missing here?
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You got me. I understand nozzle distance to combustion cup so you aren't spraying out of the bowl. I would have thought if placing the nozzle to advance the timing then the injector would have to be placed lower, not higher.
 
Ghostman said:
I don't see how changing washer thickness is effecting timing?? It still popping off at the same time, the nozzle is just further down or higher up. It's not making it pop any sooner in the crank rotation?? What am I missing here?
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pretty sure they are saying with increased depth you can then add timing and be in bowl. not that increasing depth itself alters timing.
 
Are those numbers "amount removed from standard washers" so they are lowering the nozzle as opposed to shimming it?
 
It doesn't effect injection timing per say. The injector will spray at the same time and piston position, but now that the nozzle is deeper with a thinner washer it would allow you to advance timing and still be in the bowl, if that's what your goal is anyways.. Approximately .038-.041* per .001'' with a crank angle of 25-30* accounted for. If you are going from a 1.5mm (.059") washer to a 215 style .6mm 3930324 (.024) washer, that's a difference of .033" after accounting for the linear angle of the injector. Add the .040" shaved off the head for a total of .073". Then take your piston travel distance per degree @ crank angle and multiply that by 73.. I may be off just a tad, given that I've had some whisky with my brisket sandwich.
 
So that is amount off standard washer. Thanks. I thought that was shimming it up same as what they use after decking the head.
 
BBQ'ing aluminum aint cheap =(

Is there a noticeable loss in compression if you use high torque head studs on a stock motor, no torque plate hone? I have seen some pics of the low spot thats left without the plate... created by the stress of the block holding that extra load.
Wonder if that extra void allows more hot gasses down into the void between the cyl/ring/piston crown and contributed to the failure?
I havent done anything with the block except torque the snot out of the unobtanium 625's I got on there, no plate hone.. sure hope Im not courting disaster lol.
 
Thanks for the loads of info guys! Read every post carefully. As a full time student it is hard for me to set aside money without a job but I have been flipping trucks and selling parts to get there. After finals week, I plan to bring the block up to UFC for tanking, resurface and a torque plate hone. If I remember correctly, the most OOR I saw on a cylinder with the new block was .0015. The least was .0005. Pretty good in my opinion and should get a little better with a proper hone. Also, the taper was at most .0015 and at the least .0005 between cylinders. Again, not bad.

The plan is to reuse these 210 pistons. I will have a friend stick them in a lathe and taper above the top ring land .005" and fly cut .100". Polydyn will coat them. Then, I will deck head .040 (leaving room for the future if I want to deck more). Over break, I will polish rod beams and balance them. Pistons rods and wrist pins all weighed to within a gram of eachother. Also, I want to lighten the wrist pins because I might as well while in there. I can't believe how heavy they are. I only want to bore out the ends and knock around 100 grams off each one. It will make a minimal difference at 2000 rpm or so but the weight along reduction with reduced drag from oil retention on rod beams and the reduced reciprocating weight should net me another 25hp. Lots of hours but my time is free. I have yet to inspect the crank after this event. But plan to run the H series bearings. Also, I already have billet piston cooling nozzles and they look to have done fine the last 20k miles. I think I will reshim the oil bypass to get it up around 50-60psi at a hot idle.

I think I will sell the marines and go with contagious 5x14 or 5x16. I would like to see 600hp and it shouldn't be too hard with what I already have and what I plan to do...

As far as a piston to wall clearance, what do you guys recommend for a performance street engine? Also, what is the most OOR you should see on the big end of a rod? The wrist pins still felt good.
 
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