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red13

flat or dished pistons

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Flat tops are more fuel efficient but change the head to match.

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well got a l16 210 head or a l18 head which one should i go with i am running a l16 engine block

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well the block i got the guy had it honed so the bore still at 83mm, but i am going to get it magna fluxed hot tanked and see if i need to bore it .30 over

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I would plan on a bore. 

Stuffing 83.xx into a honed 83.xx hole is merely a band-aid. 

 

Boring a block to fit oversized pistons is more like having a new block. 

 

 

 

For the price of machine work you can just source an L20B for more power out the box. 

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these are my current pistons the one in the middle has the worst damage

04111418251.jpg

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yeah i know the l20 is a better engine, but i like keeping my truck stock.  As much as i can.  Also its what i could afford right now.  I just spent 200 on a block for a l16

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What is wrong with the piston? It looks OK to me a little carbon won't hurt.

 

And what's wrong with 83 mm pistons in an 83 mm bore? Measure both and if they are in spec, you don't need an overbore.

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just the center one is beat up on the rim of the dish and some dimples i guess i an burnish them out.  The other 2 have valve damage,but i can do the same.

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The piston to bore clearance is 0.001" to 0.0018" or roughly 1 to 2 thousandth of an inch. Newsprint is about 2 thou. Stock pistons are not 83mm, they range from 82.985mm to 83.035mm and the same goes for the bore. No bore is exactly 83mm. Those that are slightly over get a 'larger' piston to maintain that 1 to 1.8 thou clearance. Definitely measure the bore in 6 places and check for oval and taper and over size if needed. Oversize pistons cost the same a stock ones.

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i really wanted to know though is flat better or should i go with ones with a dish. and what head i should use.

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Flat tops are more fuel efficient if a closed chamber head is used.

 

Get a 210 closed head (peanut-shaped chambers). There is also a 210 open head which is low-emissions.

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Those aren't even stock pistons.  I don't know what they're from.  L-series pistons don't have valve cutouts, and those aren't Z-series pistons either.

 

Flattops would increase compression, and with that semi-closed chamber 210 head might increase it so you'd need to run higher octane fuel to prevent detonation.  But maybe not.  Those valve reliefs had your compression a bit low to begin with.

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Stock 210 L16 head...

 

head210L16.jpg

 

210 head with stock 7.01cc dish pistons...... 8.58... with closed head... 8.21... with open head.... 6.72

210 head with true flattops.......................... 9.75... with closed head... 9.29... with open head.... 8.63

 

 

.

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You list three figures but only two types of heads?

 

9.29 compression ratio would be good. Max fuel economy.

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210 head, closed chamber (41cc) and open chamber (45.2cc). Three heads. There was a closed chamber 210 head but it's almost the same as the regular 210 for size.

 

The A87 closed or the SSSL16 219/V912 head actually drops the compression on an L16 unless you have the flattop pistons to go with it. An open chamber U67 head drops a stock L16 into the 6s.

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thanks guys see ill look into flat top pistons then.  Those ones i found are for a 240z.

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