Piston Dish/dome Volume

[jamesbissland]

Hi All

Has anyone calculated the volume of the piston dish and/or dome for these engines when the have had them apart?...

4E-FE

4E-FTE

5E-FE

5E-FHE

I know the 4E-FE has a positive displacment dome, just wondering if anyone knows just how much, and the other too?

I've just got into a bit of strife with MotorSport NZ, and Im going to have to kill 31cc when rebuilding my 4E to get it to 1300cc to race in my class.

the only way I can think of doing so is to shave quite a bit off the head/block (has not been determined exactly how much yet) to loose the cc, but in doing so, my C/R will got throught the roof, so I am trying to find ways of de-compressing it to a suitable level 100 octane will handle.

Any thought?

Thanks all,

jb

[Bibbs]

31 cc's is a lot to shave off fella .. and then the valves may be a touch low and start hitting pistons ..

Would it be better to go with pistons with the valve holes cut in (if you know what I mean) so stuff doesn't collide?

[jamesbissland]

Yeah, that is true, but I need to loose it.

I see the 2E engine is only 1295cc...also having a 73mm bore (instead of the 4E's 74mm)

What puzzles me is with the 4E's.. the FE is 1331 cc with the same bore and stoke as the FTE, however the FE has a 9.6:1 C/R, and the FTE has a 8.2:1 C/R.

From all the research I've dont on the net about C/R's and volumes and how it is all effected this shouldn't be, inless the internals are very different.

To have the lower C/R the FTE must have low displacement pistons (in terms of the dome), but then, that would incress the CC rating over the FE, so to lower the (FTE) CC back to 1331cc, either the crank, rods or throw must be different to the FE; unless the piston sits slightly down on the rod from having the position of the piston pin changed??

Hmmm...

[mum's car]

I'm sorry James you can shave all you like off the block but your cc's will still be the same. Cubic capacity is the measurement each cylinder using the bore and the stroke of your engine, the only way to reduce capacity is to decrease stroke length or bore diameter. By shaving your block or head you will only increase your compression ratio, not reduce engine capacity.

[nrgizerbunny]

the only way i can think of doing it is to use smaller conrods, however this will reduce your torque as the lever arm becomes shorter.

have a nice day

sv

[jamesbissland]

I'm sorry James you can shave all you like off the block but your cc's will still be the same. Cubic capacity is the measurement each cylinder using the bore and the stroke of your engine, the only way to reduce capacity is to decrease stroke length or bore diameter. By shaving your block or head you will only increase your compression ratio, not reduce engine capacity.

Thanks for that mum

I've had to have a second look at this, as to tell you the truth, I was a bit 'ummm nah' about it at first, but after looking at it again and drawing a few diagrams, you are dead right!! :hokus-pokus:

All the other variables I was thinking about like deck height, gasket thinkness, dome/dish to effect volume/displacement are actually a constant absolute measurement, that will not change from static pressure to TDC (eg, it wont effect the amount of air (or volume...displacement) and will be the same should I say, 'area' at the bottom of the stroke to the top) drawn in to the cylinder. That is govened by the vacuum created by induction stroke for maxium displacement induction), it will just effect the area that all the charged is crammed into before BANG!!

I get ya now!!! (sorry, its all a bit messy, I at least I understand it!!)

Thanks for that man. :D

Well in that case, I might have to got for a 2E block (73mm bore) with the 4E 16V head, then that'll give me 1296cc.

Does anyone know if that will work?

Thanks again!

jb

[mum's car]

Anything to help a fellow Kiwi.................or Starlet owner. :D :D

[penyu]

what about if i use block 5E can i used it with mazda B6 turbo piston...???

and what about 5E oversize piston??? can u help me bout this matter...

tq so much...

[penyu]

:(