Toyspeed.org.nz Message Board

by **ChaosAD** » Wed May 19, 2004 7:03 pm

I have a standard bluetop bottem end and head. I also have a trd 0.8mm head gasket.

Does anyone know what volume the combustion chambers need to be in order to get a CR of 10.5:1?

Id also like to know the swept volume and the volume between the pistons and the deck of the block if anyone knows them.

Thanks,

by **matt dunn** » Thu May 20, 2004 1:27 am

Does anyone know what volume the combustion chambers need to be in order to get a CR of 10.5:1?

37.7cc

if the engine you have now is 8.5:1 then it will have combustion chamber of 46.67 cc

so you will need to remove about 9 cc of space

Id also like to know the swept volume

1587 cc

by **ChaosAD** » Thu May 20, 2004 8:17 am

does that combustion chamber volume include the head gasket and the tops of the pistons? or is it just the head?

by **mister2** » Thu May 20, 2004 10:32 am

theres a thread about 10 below this which gives the math to work it out...

*edit* sorry thats such a f*cking useless comment by me *edit*

nick

by **matt dunn** » Thu May 20, 2004 8:50 pm

ChaosAD wrote:does that combustion chamber volume include the head gasket and the tops of the pistons? or is it just the head?

thats just a math calculation from the swept volume so it will include the gasket head and everything.

by **Drifter4ag** » Fri May 21, 2004 2:01 pm

or for a rough estimate according to lyn rogers .1 off head/block/gasket = .1 up on compression ratio ... soooo
say bluetop has 9.4 .. stock bluetop headgasket is 1.0mm and redtop is 1.2mm .. run a .8mm gasket on bluetop and you are up at 9.6 and on redtop you are up at 10.7

by **ChaosAD** » Fri May 21, 2004 7:33 pm

Oh, is the stock bluetop headgasket only 1mm?

by **Drifter4ag** » Tue May 25, 2004 3:06 pm

according to our special gasket man yes ..1mm and 1.2 for redtop/4agze

Website · by **Rollin'** » Tue May 25, 2004 8:16 pm

i shaved off .5mm of mine, was told it would raise a couple of points, from 9.4:1 to 9.6-7:1.

so if .5mm raises it .25 points, to get to 10.5:1 thats a reduction of 2.125mm.

and im sure i measured my old headgasket at 1.2mm

by **ChaosAD** » Tue May 25, 2004 10:13 pm

Drifter4ag wrote:or for a rough estimate according to lyn rogers .1 off head/block/gasket = .1 up on compression ratio ... soooo
say bluetop has 9.4 .. stock bluetop headgasket is 1.0mm and redtop is 1.2mm .. run a .8mm gasket on bluetop and you are up at 9.6 and on redtop you are up at 10.7

I dont see how that would work, cos the cross sectional area of the combustion chamber in the head is less than that of the head gasket/block because of the squish bands.
Therefore removing 0.1mm off the block or head gasket will be will remove more volume than the taking 0.1mm off the head.

by **Drifter4ag** » Wed May 26, 2004 12:38 pm

forget that the headgasket size is blabla its what it compresses down to after its on that you worry about .. and im just repeating what lyn rogers told me as a rough estimate .. .1 off head = .1 up in compression ratio

by **TRDWGN** » Wed May 26, 2004 6:40 pm

And if anyone knows you can be sure Lyn Rogers knows! He's be making cars fast since before most people on here were conceived!!

Toyspeed.org.nz Message Board

how do I increace bluetop compression ratio to 10.5:1?

how do I increace bluetop compression ratio to 10.5:1?

Re: how do I increace bluetop compression ratio to 10.5:1?

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