On Oct 18, 2012, at 4:17 AM, Paul Stenquist wrote: > Nice work. It should run well. How high much boost will you run and how high > is the compression ratio?
The last time I took it to the track, brake fluid got spilled on my notebook, so I lot my records over how much boost it was making. The interesting thing is that I do remember that after a certain RPM the readout on the boost guage went way up. I think that what happened is that the head ran out of breathing. I did get a slightly larger pulley for the blower to reduce the boost slightly. Also, going from a cast iron head to an aluminum head should help in that department too. Compression ratio is 8:1 down from 8.8:1. One of the big limitations in this design is the lack of an intercooler, or any way to add one. But it was, in theory, a bolt on supercharger kit. > It's unfortunate that pump gas is a limiting factor there. With that port > design, you almost have to have some kind of forced induction. I would have > thought that the Brits would have figured out crossflow porting by that date. The B-series motor was designed in 1952, and the Brits used that motor in everything from sports cars to the metro van. They did have a crossflow version of it, which was used in the MGA twincam. There are crossflow heads available: http://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=62849 Realistically, if I were to do everything that I wanted to fix up my MGB, by the time I was done, I'd have a miata. The one big change that I'd really like to make to the design is a megasquirt engine management system, going to fuel injection and crank fired ignition. > Paul > On Oct 18, 2012, at 4:30 AM, Larry Colen <[email protected]> wrote: > >> Now that I've got paint on the engine compartment, I started cleaning up the >> motor in preparation to installation. >> As I document the progress, I kind of like this shot: >> http://www.flickr.com/photos/ellarsee/8099334872/in/set-72157631773384091/ >> >> For the motorheads that have any interest in such things, between the >> ported aluminum head, aluminum fidenza flywheel, aluminum back plate and >> lightweight reduction gear starter, I've knocked about 50 static pounds off >> the motor. Other go-fast goodies include the roller rockers, custom cam, >> pauter rods, venolia pistons, and of course the supercharger from >> http://www.hi-flow.com/ >> >> In the previous incarnation of the motor, which unfortunately had a cracked >> iron head, I was getting a bit over 90hp on the chassis dyno, and once saw a >> bit over 100hp to the ground, just before the head gasket blew. I'm hoping >> that this version of the motor will hold together a bit better and put a >> little over 100hp to the ground. For people not familiar with MGBs, a >> rubber bumper ('76-80) MGB would put about 50hp to the ground, a stock '69, >> like Jasmine would put about 65hp to the ground. Before supercharging, I >> was getting a fairly consistent 75hp to the ground. So an MGB that puts 100 >> to the ground is pretty quick for an MGB. Or about average for a spec >> miata, which you could buy, or even build for significantly less than I have >> invested in Jasmine's motor. It must be a symptom of the same mental >> condition that causes me to shoot with Pentax gear. >> >> >> -- >> Larry Colen [email protected] sent from i4est >> >> >> >> >> >> -- >> PDML Pentax-Discuss Mail List >> [email protected] >> http://pdml.net/mailman/listinfo/pdml_pdml.net >> to UNSUBSCRIBE from the PDML, please visit the link directly above and >> follow the directions. > > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- Larry Colen [email protected] sent from i4est -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
