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stock 225 deck height? and build a motor
https://www.slantsix.org/forum/viewtopic.php?t=62205
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Author:  Charrlie_S [ Mon Apr 16, 2018 8:52 am ]
Post subject:  stock 225 deck height? and build a motor

Question for you guys that have actually measured the stock 225 deck height. What is it, in real world numbers? I'm trying to get an estimated CR for a possible engine. All my 225's are disasembled. Ask me on a 170, and I'm good. I've only built one 225, and don't remember what it measured. Need to find an average. Thanks

Author:  Badvert65 [ Mon Apr 16, 2018 10:40 am ]
Post subject:  Re: stock 225 deck height?

I had measured my 79 block prior to machining and it was 0.156".
I seem to recall that the 65 and 73 engines I have were in the same ballpark, but I did not record those measurements.
I can measure the 73 engine this evening as I still have that one on a stand with the head off. (The 65 engine was scrapped-cracked block).
FYI, all of these are 225 engines.

Author:  drgonzo [ Mon Apr 16, 2018 10:51 am ]
Post subject:  Re: stock 225 deck height?

One of mine measured .183" for sure. The other in the same ball park, like .178".

Author:  Doctor Dodge [ Mon Apr 16, 2018 11:03 am ]
Post subject:  Re: stock 225 deck height?

- .145 is the "advertised" number but most factory 225 Slants I dis-assemble are in the negative .175 to .185 range.
DD

Author:  DusterIdiot [ Mon Apr 16, 2018 12:20 pm ]
Post subject:  Re: stock 225 deck height?

Quote:
- .145 is the "advertised" number but most factory 225 Slants I dis-assemble are in the negative .175 to .185 range.
I concur with Doc... It was a bit more on the 1963 Truck motor I had, about that range for the 1967 Valiant motor...closer to -.175 on the
1974 and 1976 forged crank motors I have pulled apart... the late 70's cast crank motors can be in the -.145-.175 range.

Author:  Charrlie_S [ Mon Apr 16, 2018 12:25 pm ]
Post subject:  Re: stock 225 deck height?

OK, thanks. I thought I remembered .178 but wasn't sure. So I will use .175, estimate, to see where I will come out, with different pistons and/or rods. I have three different pistons, and three different rod lengths available, Want to use an unmilled (or just slightly) head, and be in the 12-13 CR range. Problem is all three pistons are a different bore, so can't mock it up, and get actual readings. Need to use math.
PS: Pistons Old Jahns 12.5 to 1 cast domed .060
Clevite TC 2349 std 2.2 dished hyperutectic
TRW L2502F 1.00mm 2.2, forged flat top.
Rods 170, 198, 225

OK Guys if it were yours, what would you build. Race only, no power adder (for now, anyway), Have a couple of cams over .520 lift, and over 286 adv dur. Clifford intake, 600 afb carb, msd 6 with mopar slant six dist, Clifford or Aussiespeed long tube headers, Head is not built yet, but have a set of engine builder valves. 9 1/2 inch converter, 904 trans, 4.56 rear gear, 9x30x15 slick, weight 2700-2800 lbs.
Feel free to make suggestions.

Author:  Joshie225 [ Mon Apr 16, 2018 12:27 pm ]
Post subject:  Re: stock 225 deck height?

I had one at -.187". Math had that motor at a compression ratio of 7.6:1. :oops:

Author:  Dart270 [ Mon Apr 16, 2018 1:04 pm ]
Post subject:  Re: stock 225 deck height? and build a motor

It depends a lot on the year. I usually get 0.180" for forged motors.

Build depends on what parts I would want to use up. Easiest would be Jahns and 225 rods, and likely cheapest to build. Or, if you want a forged piston, then use 225 forged pistons on 225 rods, mill block 0.150 or so and do the rest with the head.

Hmmmmm...

Lou

Author:  Charrlie_S [ Mon Apr 16, 2018 1:20 pm ]
Post subject:  Re: stock 225 deck height? and build a motor

The forged TRW pistons are for 2.2. Don't have any forged 225 pistons.
OOOps, yes I do, but they are .040 over for my 170 turbo engine.

Author:  DadTruck [ Mon Apr 16, 2018 7:19 pm ]
Post subject:  Re: stock 225 deck height? and build a motor

The forged 2.2 l pistons with the 198 rods would get you to a near zero deck block. You could then mill the head some calculated amount to get to your desired CR. Depending upon how the heads cc after the valve work, it should not take much.

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