Walkinshaw

Im investigating cams atm, and with regard to straight LPG, not to many companys have off the shelf hipo cams of the OHC I6 for straight LPG. Ive been led to believe that manafold vacume is a must for efficent LPG running, and thus i should use a cam which has little to no overlap, but has large lift and duration. Does this sound about right?

Does anyone have details of people who have had experence running dedicated LPG performance camshafts.

__________________
Ive been described as a vault of usless random knowledge.

Ill take it as a complement i think.............

ebxr8240

You don't say what model you have. Check see if latter model cam fits. From memory the latter model had more lift from 600 to 635 approx.. If they fit etc...Talk to www.crowcams.com.au

__________________
Don't be afraid to try something new. Remember, amateurs built the Ark...Professionals built the Titanic!
.
Tuned & maintained by "Peppertree Perfmormance". Dart block, Scat 4340 steel crank, Custom C.P pistons.Oliver rods.. Mal Wood twin plate clutch.. Twin SC61/2's,482 rwkw/ 645 rwhp..
Passengers, myocardial infarction material..
R.I.P Possum...

tonyk

Large duration gets you overlap. One definate target for all ford cams is an exhaust bias of 6-12 degrees if possible. Loosely speaking any performance cam is a performance gas cam. The real issues with gas is ignition and compression. Gas is just a hydrocarbon fuel like any other, just with different (plus and minus) properties.

I use a crane 296h in my gas only motor. This is no drag cam by a long shot for a big motor but for a 6 it would be too wild I think to get an idle. Having said that... gas actually "calms" a big cam as it has a less combustion energy. It is also delivered to the motor in the perfect form - vapour, so no atomisation issues like with petrol and pulsing air flows at idles.
My 240 degree (fair overlap) idles at 500 in gear. It scares the neighbours and sets off car alarms but it idles. Practically speaking its too long and needs less inlet duration.

An OHC should be able to deal with .450" to .500" lift at 212-225 degress. It gets real choppy after that and your wringing it out to hit max power. 10 degrees more on the exhaust than the inlet but the lift about the same. A dual pattern is fine too just get the extra exhaust duration.

__________________
Well done SA pollies (for once). Hoon laws are long overdue to protect car enthusiasts against idiot drivers.

Walkinshaw

ive got an EA 3.9.....(just to let ppl know what motor)
In the forseeable future itll be rebuilt with high compression (Between 10.5==>11 i think should be allright) some mild head work and a cam. Extractors+2.5" exhaust will be on the exhaust side of things

__________________
Ive been described as a vault of usless random knowledge.

Ill take it as a complement i think.............