Redsnake,tough question to answer with any kind of accuracy as it all depends on the porting and rest of engine and pipe used. Alot of times the jetting wont be as big with ported cylinders as with a stock cylinder as the duration in which the ports are open is longer allowing more fuel mixture in over a longer period of time so the jetting doesnt go up as far. I would try a couple sizes and do plug chops and piston wash checks.
Just remember that the number 1 enemy of a 2 stroke engine is HEAT. high compression will make heat faster in a engine.
Just remember that the number 1 enemy of a 2 stroke engine is HEAT. high compression will make heat faster in a engine.
Don center layer removed. I searched alot of posts 100 seems the norm on the pto stock, so maybe I'm ok. Paul
redsnake3
New member
mrviper700 said:
well, im running colder plugs and straight 110 so it should help to stay cool, i was just trying to see if it was a big change. raced it today and it sucked, came in second but lost alot of power compared to the stock head. ended up losing about 5-7mph on top in 660'.
vipertripplexxx
New member
Mac,
The reason for wanting more squish clearance with the CPR's is they run at a higher RPM, and having too much squish with pump gas can cause problems with detonation/loss of power up top. I was just wondering what you were running, and it sounds like your gonna be fine with your setup. Thats exactly what I was thinking.... .050" squish, and about 145 on the compression. If I had to run over 9000 RPM probably closer to .055".
I run the stock SRX pipes/CDI in my viper so .045" is for me.
Shouldn't be any complaints with that!!!!!!
Mac
Member
RPM Question - CPR
XXX thanks for your input. I thought the idea behind CPR running higher RPM was a good thing because the timing is retarded thus creating less heat. Many pipe designs that run less RPM are operating in a timing advance that many people beleive is a bad place to operate. Take Bender for example dont they burn down more that any other pipe design because of the RPM timing spike issues.
That hose quote is classic. LOL
XXX thanks for your input. I thought the idea behind CPR running higher RPM was a good thing because the timing is retarded thus creating less heat. Many pipe designs that run less RPM are operating in a timing advance that many people beleive is a bad place to operate. Take Bender for example dont they burn down more that any other pipe design because of the RPM timing spike issues.
That hose quote is classic. LOL
The rpm wouldnt be any concern, advanced timing puts more heat into the piston, retarded timing puts more heat into the pipe. Therefore the higher rpm helps you with triple pipes, and the viper cdi box. Along with the actual stinger size of the pipes that would be the issue, a tighter stinger would place more heat back into in the piston crown and require a differnt head set up then a larger diameter stinger would, (larger diameter)it would retain less heat and give you more prolonged running wide open across a lake, but would also provide less performance in short drag racing runs.
ExpertXViper
New member
MRVIPER: I know this was answered some what in posts above BUT if I measure the CC and the Squish. Can I figure out what domes I was sent? or figure out if there safe for pump fuel?