Old Crower Mileage Kit

[KenMc]

Thank you KiwiBacon. BSFC tables are hard to come by. Would 230 equate to about 0.38 lb/hp-hr?
More importantly, do you know the basis for the valve timing? Seat to seat or at 1mm? Thanks again for the info.

[KiwiBacon]

Originally Posted by KenMc

Thank you KiwiBacon. BSFC tables are hard to come by. Would 230 equate to about 0.38 lb/hp-hr?
More importantly, do you know the basis for the valve timing? Seat to seat or at 1mm? Thanks again for the info.

Yes 230g/kwH works out to 0.38 lb/hp-hr. I'm afraid I have no information on the valve timing.

[Bill Starks]

I also builit one of the Crower kit milage engines using the high compression pistons and extended intake closing cams. It worked well but didn't get the results I had hoped for. We put it into a 3500 series chevy van hauling body shop supplies around and it only inproved the mileage a couple of miles-a-gallon, and power was down. The idea is sound and I wished I had the kit to try again; for use in a lighter vehicle.

[KenMc]

It is good to see that this old thread is still alive. I have been busy putting a supercharger and larger injectors on the wife's Solstice. It has variable valve timing (VVT) that I hope to play with sometime for mileage and bleeding off cylinder pressure at low rpms but I don't know that the people who hack the ECM's have the VVT very well sorted out. The VVT advances the intake valve and retards the exhaust. Whereas I was wanting to retard the intake. I think they are using it somewhat as internal EGR.
I have read where very early intake closing works the same as late with less pumping losses. Basically after the intake closes part way down the stroke, the piston just works in a vacuum for the remainder of the intake and an equal amount of the compression stroke. My only problem with that is that you eliminate any dynamic filling at higher RPM's.

[Bill Starks]

One advantage to the late closing, hence pushing the charge mixture back into the intake tract, is improved evaporation and homogenized mixture, that would enhanse fuel economy on the next induction. Not too different in theory to Smoky's hot cycle engine. Get it hot and evaporate. Just no turbo to recompress.
Thanks for you comments on this thread, as I hadn't heard of the early intake closing.