Guest BrainFluid Posted September 24, 2006 Reading PumaRacings excellent tuning guide has left me with some ideas. Seen as I'll be having the exhaust valve seats replaced with harder ones for eventual Lpg would it be worth while having larger seats and valves put in there while I'm at it? I'm theorising that the extra bhp that will arise from this would balance out the loss of power when running on lpg...But give me more Bhp for when I just cannot resist razzing around on petrol every now and then I am unsure after reading Puma's guide as to wether both the inlet and exhaust valves are increased in size or if its just the exhaust valves? Also I'm unsure if you can increase valves and seats without the need for porting? As soon as I have a good idea of whats going to happen to the head I'll pop over to my local cottage industry metal workers and get a sample quote. Share this post Link to post Share on other sites
Guest BrainFluid Posted September 25, 2006 I'm also thinking about getting the inlet valves 2 way angled at least (searching shows that theres not really enough room for 3 way angling on standard inlets) to make dammed sure that there is a good gas tight seal there to prevent any backfiring. Does anyone think that having larger exhaust valves and 2 way angled inlet valves would be the way to go? Sounds good to me but then I'm probably a number 2 customer that should be put up agaist a wall and shot, lol, only joking. Well, I hope so anyway! Share this post Link to post Share on other sites
petert 556 Posted September 25, 2006 Bigger exhaust valves is a waste of time and expense. Just buy quality tuffrided stainless valves and have 3 angle seats cut. Share this post Link to post Share on other sites
Guest BrainFluid Posted September 26, 2006 Excellent. Thanks for the reply Petert. Thats all my valve seats yes? Share this post Link to post Share on other sites
johno_78 2 Posted September 27, 2006 lpg has a much higher octane rating than petrol. so you would benefit more by changing the ecu to take advantage of this fact, rather than focusing on the valves for a few bhp. Share this post Link to post Share on other sites
Guest ashnicholls Posted September 27, 2006 Yes was going to say about the octane. You do lose power with a standard engine. But as its higher octane, LPG can be used safely up to a compression of 14:1, which will give you a nice power increase. My mate is running a 5.5L V8 Mustang, completly on gas, with high lift cam and high compression. Share this post Link to post Share on other sites
petert 556 Posted September 27, 2006 rather than focusing on the valves for a few bhp. it doesn't matter how much hp you have if you have tear out the valve guides and pound the seats because of poor material choice. Share this post Link to post Share on other sites
