Get The Data Right! Argggggh

[240260280z]

Help.

For a stock L28 engine, the piston pops out of the block but the AtlanticZ and OzDat engine planning tools do not match!!

I looked at my FSM's to double check all numbers:

Connecting Rod Length:

L28 connecting Rods c-c 130.35mm in FSM's

Honsowetz, Monroe, and on-line engine calcs give 130.20mm (so this is an error but not enough to make the model fit the real world.)

Piston Compression Height:

Not in FSM's but it is 38.1mm everywhere

Crank Stroke:

79.0mm in FSM

Still, with the con rod adjustment I get a piston above deck at 0.08mm and OzDat tool gives 0.06mm using the shorter rod data.

Real world for L28 is ~ 0.584mm protrusion of piston above block (nearly 1 order of magnitude higher!!!) See picture at top.

It seems to point to this question: Is the block height correct at 207.85mm /207.87mm /207.90mm?

It would seem that the block height needs to be ~207.37.... did someone write a "3" and read an "8"?

The only source I can trace so far, for this value is 207.85mm in Tom Monroe's book however he has the rod length that is shorter than the FSM..... help

Edited April 11, 2015 by Blue

[Patcon]

Does this block have a factory deck height?

C

[240260280z]

Yup: http://forums.hybridz.org/topic/58658-pistiondeck-height-misinformation/?p=536534

[siteunseen]

They didn't have the benefit of the "infonet" back then. : )

[Zed Head]

To be rigorous, you'd have to know the individual part tolerances, and do a geometric dimensioning and tolerancing calculation to know the range of "pop-ups" possible.  You could have a combination of +'s and -'s that are in spec. and give what yours shows.