Mid- Engine Modified Sports

[manta22]

Thank you, BR. I just ordered that MFI book and I am looking forward to studying it.

[Rex Schimmer]

Neil,
I was doing some Mazda rotary work at Drake Engineering back when Gurney was developing the Chevy small block for Indy racing. As I remember "Stump" Davis was doing most of the work there on the engine. He developed the down nozzle injection for the small block. He bored holes in the head from the spark plug side and then they welded solid round rods into the bored hole, then drill and tapped them for injector nozzles and the fuel was squirted almost directly on the back side of the intake valve. With a lot of development and dyno time they were making some very good HP. Stu Van Dyne, who was working at Drake saw the advantage of this and developed it for dirt car engines. I think the first was Jr. Kurtz's dirt champ car, the Plastic Express, which also picked up an impressive amount of HP from the down nozzle modification and went on to win both the 82 and 83 Hoosier 100. Stu also made them work on 410 sprinter motors. Regretfully Ron Shaver picked up the idea and was given the credit for getting down nozzles on sprint cars when actually it was Stu.

Any way do the heads have plugged ports on the spark plug side?  As I remember Junior's dirt champ motor, 355 cu.in, iron block, was making about 835 hp at 8500 rpm and that was when most of the other cars where making 750 hp max and not turning over 7500. You may have a real piece of history!

Rex

[manta22]

Interesting history, Rex. I bought this Donovan as a bare block- no heads, crank, etc. It came from the Seattle area and I heard that it had been in a boat used for off-shore racing. I had it drop-shipped to Donovan where they replaced a couple of cylinder liners and then shipped it to me.

Having those heads would be sweet! Do you know that block serial number?

[Rex Schimmer]

Neil,
No luck on the S/N for the block as I was working mostly on rotary stuff at Drake so was only involved with the Chevy stuff as an interested observer. My bet is that the original heads are pretty much gone as all of the machine work and welding probably had an effect on their life. After the down injectors worked out so well, Brodex made special heads that had the injector bosses already cast into them.

Rex

[manta22]

My original YouTube build diary had no narration, only some text titles, so it wasn't very helpful in telling the story of the details of my build so I re- edited it completely. Now it has a narration soundtrack so it may be a bit more interesting but it does run pretty long (about 56 minutes!) so grab a beer or two to watch the whole thing.  https://www.youtube.com/watch?v=LFu8QfUVHlU

[Peter Jack]

Lunch and a coffee did the trick Neil. That was a really well done video. 

Bye the way, once you get the hang of it the Crower injection is a piece of cake. We ran it on a big block Chevy powered sprint car. Power was never a problem.

Pete

[manta22]

Thanks, Pete. I'll probably go back to the Crower when I get things sorted out.

[manta22]

I noticed that my quick-release steering wheel hub seemed a bit loose on its spline so I decided to replace it. On another car I had used a hex shaped quick-release hub but it had more play than I thought it should have. I drilled and tapped a hole in the hex aluminum hub for a screw with a knob on the end. I tightened the screw just enough to remove all the play, similar to a "gib" screw on a milling machine, etc. This worked but made it more difficult to slide the steering wheel off.
After looking at many quick-release steering wheel hubs, I decided on a splined hub from Mark Williams. The splined sleeve slips over 3/4" dia tubing steering shaft and either bolts in place or is welded. The hub itself is internally splined with one tooth missing for indexing. This slides on and off easily but has virtually no play. If you are looking for a nice quick-release steering wheel hub I recommend you look at the ones from Mark Williams.
 

[manta22]

I've been working on my car, getting it ready for Bonneville in September, I decided to take off the front fiberglass so that I had easier access to a few things under there. Arrrggghhh... dirt and salt everywhere. The salt I can understand but the dirt? I've never been to Elmo.   

Cleaning everything up is a PITA but it needs to be done. It is a good thing I live here in the dry desert or the salt corrosion would be far worse. It's a good thing I don't drive this on the street. If I got stopped by the police I'd probably be taken away in handcuffs- the salt crystals look just like crack cocaine that I've seen on TV.

[Speed Limit 1000]

That is why we take every panel off the Bockscar lakester when we get home from a race. Corrosion was a lot less of a problem in Denver than it is now since the car in in Stainless's shop in Kansas

[WOODY@DDLLC]

If I got stopped by the police I'd probably be taken away in handcuffs- the salt crystals look just like crack cocaine that I've seen on TV.

Neil, you already have a record with your carcaine habit! 

[Stan Back]

You may have never been to the salt -- when the salt was made up with salt.  Now the water's dirty 'cause it's from the mud, less than an inch below the salt.

If you're building something for Bonneville, don't delay.  The rail cars are still moving and not much else is happening.

[fordboy628]

Tom Burkland-

This was how I originally built my engine. The MFI looked like it was going to be too hard to learn so I switched to an 850 Holley on an Edelbrock 4+4 manifold. It's now running a Proform 850 but in the future I may switch back to the Crower. Looks cool, too.

Neil,

The Crower MFI systems I have seen are "constant flow" Vs the timed Lucas/Cosworth MFI more common on 4 cyl engines.   Regardless, Jim Kinsler and his minions are my go to guys for MFI issues/problems.   They are not cheap, but have always solved any issue for me.  Checked out the link and the book, looks like great info, certainly worth $50.

[manta22]

I did buy the book you mentioned and it does look good. After I get everything else sorted out I'll switch back to the Crower MFI.

Back in the Can-Am days we ran an M8C McLaren with an aluminum big block Chevy built by George Bolthoff . It used Lucas timed injection. Nobody but Bolthoff ever tweaked the injection.

[fordboy628]

I did buy the book you mentioned and it does look good. After I get everything else sorted out I'll switch back to the Crower MFI.

Back in the Can-Am days we ran an M8C McLaren with an aluminum big block Chevy built by George Bolthoff . It used Lucas timed injection. Nobody but Bolthoff ever tweaked the injection.

Lucas timed MFI has an "operational checklist".   IF, you stick to the checklist, and have the special tools, piece of cake.    If you just "futz around", well . . . . bad things can happen.    George knew what he was doing.   You need the right cam for the application, because the adjustment range is so narrow.    High altitude (Bonneville . . .) needs a different (leaner) cam.

Constant flow is much more "tuneable" and tuner friendly.   And it's cheaper.