Paxton
 

I want to install a Paxton on my 392 carbeurated stroker but the limiting factor is fuel mixture. I have received many warnings about running tooo lean which would toast the motor. I have forged pistons and 10:25 to 1 compression and was told I should not run more than 6# boost. I would like to get first hand info from anyone who has experience with the same set-up.

Thanks.......John

You will need to lower your compression ratio. 10.25:1 seems a bit high for a blower.

I've heard nothing but bad things about putting a Huffer on an engine with more than 8.5-to-1. Detonation problems, my suggestion would be Put the 351 crank back in, and use some deep-dished pistons for that blower.

old thread/post by john/ my 401k...but point is still current not knowing what he did since january 04 vs his paxton intent. i had a paxton VR4 on a 351w motor and blew the tops off 3 pistons and the edges off of two more after 3000 miles. blower was great, but moment of truth came when engine did not cooperate under pressure. too much boost, too high compression, wrong pistons. if ya build an engine for a huffer intention then the results should be fine, but not as a direct add on without other internal changes for the blower. i was advised against putting one on, did it anyway. took a chance and lost. but while it was there it was something else. decided to go a safe route after the 351 blew, sold the old engine and put in a 392 ford racing stroker WITHOUT a blower. now i have a blower in the garage as conversation/display art ! LOL...still looks pretty...might put it on my 65 modified mustang convertible, when i am in another foolish mood. darned, i liked that blower... bill.

I'd think of converting to EFI for best results with the blower. An EEC-IV system can keep the engine much closer to the edge than a carburetor can without emeinent engine damage due to environmental changes. Go with a thicker head gasket to loose a little compression, and you can also have a little materiel removed from the combustion chambers. If you can get it down to ~9.5:1 C/R then 8-9 PSI shouldn't be a problem with around 18* of timing. Those will be good baseline . If you have a boost retard device, add 10 degrees to the total timing and subtract 1 degree per PSI. That is a good starting point for the carb or EFI tuneup. Tune it on the dyno either way and keep good fuel in it. Also, you can mix a gallon of tolulene and a gallon of Xylene with your pump gas as an extra margin of safety. Sounds like a pain, but if it's not a daily driver it might be worth it for an extra 200 horsepower. If you mix 30% by volume, you can realize 100 octane unleaded gas for a fraction of what commercial VP/Trick race fuels cost. ANother solution would be methanol/water injection. That will make your engine think that pump gas is really 100+ effective octane with the methanol serving as an additional fuel source and charge cooling media and the water serving to cool the hot parts involved in the combustion event.