my buddy is having his head shaved down for his formula 3, i was wondering if it would be worth it to do it to my srx 700? anyone have any useful info?
Sledsquatch
New member
- Joined
- Sep 29, 2008
- Messages
- 220
- Age
- 51
- Location
- Carleton Place, Ontario
- Website
- www.simplifiedaudiovideo.com
I had the heads shaved on my older Mercury twister, it was huge performance for the dollar. Just use the higher octane fuel, I burned my engine down twice before I figured that one out. I was only 17 and the local dealer sold lawn mowers mostly. I was learning as I went.
all depend the year of the srx ....i know u can but try to contact mrviper i will give u awsome explanation
farmboy4240
Member
do a search on here. but rember to rejet i think the 2000 and up srxs had higher compression than the 98 and 99.
Last edited:
From all the info that I've read on the subject it's not enough to just shave the heads the combustion chamber needs to be recut too.
Fro
New member
Yup, ports & heads same time.
mopar1rules
Active member
Fro said:
what?? i don't think anyone was talking about porting.
mopar1rules said:
lollllll
1995vmax500le
Member
kinda off topic but what year of srx heads well fit on an 02 viper and how much should i shave off to get a bit better performance? i want to get rid of the crappy stock head.
srx heads work with oring ..viper work with gasket ...u need to get those cylinder groove for oring on viper cylinder to put srx heads1995vmax500le said:
mopar1rules
Active member
modsrx said:
srx heads will work fine w/stock viper head gasket. don't need to cut cylinder decks w/grooves for o-rings. '98-'99 heads are approx 2cc larger in cc size than the '00-'02 heads. 1995vmax500le, you will need to cut the heads .030"-.032" (thickness of viper head gasket), to take out what volume there is under squish band, that is going to get added back, w/a viper steel head gasket. also, you will need dowel pins for the heads and a custom or srx water rail. you can use a stock srx water rail. try contacting BETHEVIPER on here, as i believe he's set up vipers w/srx water rails. hauck powersports sells water rails too, for their billet head kits. i think they're like $75.
1995vmax500le
Member
can you tell me the head volumes for the 98-99 heads vrs. the 00-02 heads and which year would be the best when compared to the viper head volume??
mopar1rules
Active member
'00-'02 heads are going to be the closest to your vipers. i remember them being around 24cc. '98-'99 heads are around 26cc, i believe. the '98-'99 700 motors had a lower main exhaust port, so higher cc dome volume needed. srx heads are suppose to be setup from yamaha, to give a 6.5:1 trapped compression ratio, on srx 700 cylinders. yamaha says that center and mag domes on a viper, w/stock viper mono head, is a 6.6:1 trapped compression ratio. the pto is 5.8:1. machining .030" off a stock '00-'02 head will get you kinda close, but you will have a larger safety margin than needed....IMO. you can take more off to get the trapped comp ratio closser to what yamaha says it should be on a viper, but will need to recut squish band to get clearance correct and should recut the dome, to get the squish band area ratio correct, or else the msv will be too high. the reason you can take more than .030" off of srx heads, that are going on a viper, is because of the high main exhaust port. high exhaust port will equal more to come off of head, to get correct trapped comp ratios. make sense??
Last edited: