470 stroker compression ratio?

[mickeydee]

ok i did a search but nothing came up.so what is it?

[Wayward Son]

with a 12.5 to 1 piston,and .020" worth of base gasket it is roughly 14 to 1.

[mickeydee]

so with the je piston you sent me and 2 e-model base gaskets im running near 14 to 1.wow:eek: guess i better get some chevron 94 oct in the tank.i only have 92 oct right now.glad all ive done is just fired her up and got her warm

[f2dog]

so with the je piston you sent me and 2 e-model base gaskets im running near 14 to 1.wow:eek: guess i better get some chevron 94 oct in the tank.i only have 92 oct right now.glad all ive done is just fired her up and got her warm

Guess the same goes for me ?

What will the compression be with one s base gasket and one E ?

[Wayward Son]

this is part of the reason the RHC cams were developed.the extra duration counter acts the compression somewhat.

premium pump fuel is needed for sure.

[f2dog]

this is part of the reason the RHC cams were developed.the extra duration counter acts the compression somewhat.

premium pump fuel is needed for sure.

I will be running my hotcams to the rhc187 arrives.

As far as i understand , the hotcams has much less duration, and will give a slightly higher comp ?

Should I use 4 gaskets ,or will it be ok just with two e-base gasket (one on each side of spacer) when runing the hotcams ?

[Wayward Son]

yes the actual compression will be higher.

what is the best pump fuel avaialbe there?

[f2dog]

yes the actual compression will be higher.

what is the best pump fuel avaialbe there?

I usually tank 98 oct ,don't know how thats compared to us specs

[restosud]

it's about 92 or 93 us octane.different ron/mon calculation in europe.

same dilema here.

waiting on rhc cams for a 470 but would like to use hotcams in the meantime and don't want to take cylinder off when changing from hc to rhc.

can mix with vp c12 if needed whilst we wait until cams arrive.

what is the difference in hp with 2,3 or 4 base gaskets?

what's gas pump friendly?

i know eddie built a motor for ebrebaek with 4 base for longevity?

[Wayward Son]

it should be ok on 93,but listen for the death rattle.

[f2dog]

98 octane (Us 93) is the highest we have in europe . Next is race fuel 100+ octane(eu).

I can allways add some octane booster ,but do you think this should be necessary ?

A std. DRZ 400e runs well on 93 oct (eu) ,and it has 12,2:1 compression??

[mickeydee]

i would just go buy some octane booster to be on the safe side.

[npm]

Octane booster you buy at the auto parts store is a waste of money. You have to dump in a ton of the stuff to have even a small effect on the octane rating.

[jhondius]

How much would the comp be with one or two S basegaskets?

[f2dog]

As far as I understand ,the gaskets is the main difference in compression between the drz e and sm/s.

E- model has one single ,and 12,1:1 in comp

sm has one 3 layer and 11,3 :1 in comp

Guess that the thicker gasket lowers the comp by 0,8:1 .

So if eddie talks about 14:1 with two single ,

it should be 12,4 :1 with 2 s-gaskets.

The Je piston Eddie sent me has a 12:1 comp, guess he uses the same piston for all 470's

Correct me if I'm totally stupid:excuseme:

[Wayward Son]

changing the stroke increase the swept volume so a 12.5 to 1 94mm piston has more compression when you add the stroke.

[freewheelers]

Rule of thumb is what ever the piston is rated on stock stroke ... add one point for the stroker crank ... I.E. .. 12.5 piston on stock stroke = 13.5 with stroker crank ... I have been running 92-94 octane fuel in my bike for the last 13000 miles with no issues so far ...

I have one of the original big bore stroker 94.5mm wiseco piston on a custom offset crank pin ( +5mm stroke )running "E" cams

[f2dog]

My piston is 12,1:1 ,so the comp will be 13,1:1 ?

Think I'll try out one single e-base and one 3 layer s-base gasket.

Don't want to be in the need for race fuel,as it's inane expencive here ,and is hard to get in my part of the country.

Super 98 is about $2 a liter....

[jhondius]

i think your reasoning might be right f2dog.

that would bring you to about 12,3:1