4.3 Supercharged Chevy

[piper6909]

Originally Posted by Qingdao

EDIT: oh and I think I'm just gonna live with the glowing headers at idle... I mean they don't seem to mind being that hot at idle, and if thats the ignition timing required to keep this thing from pinging then thats what it takes.

Wouldn't too lean of a fuel mixture cause the headers to glow?

[Qingdao]

Originally Posted by piper6909

Wouldn't too lean of a fuel mixture cause the headers to glow?

Yes, but in this case its timing related. I was trying to run a locked distributer using vacuum advance at idle retard enough to correct for the timing needed at WOT.

As of last night I've given up with that idea. I ordered an MSD boost retard control box. Supposedly it takes out 1, 2, or 3 degrees of timing per pound of boost made at the turn of a dial. It cost a pretty penny so I hope its worth it.

I was almost about to take the heads off and check which cylinders are pinging the hardest. I was under the impression that 1 & 3 were/are running harder than the rest due to the supercharger's location. I also wanted to maybe lower the compression some more. BUT I took a syringe and actually measured the dish of my new pistons. They are 18ml of dish; with a 4.120" X 0.040" HG, 64ml of head volume, and nominal deck to piston I should have about 9:1. Thats a lot lower than I was guessing at. Actually measuring things helps LOL

^^^ after that revelation I decided to buy a better ignition system; regardless of its astronomical cost.


Cost aside it is a really nice unit. It records boost pressures and timing maps. I might be able to get it to communicate with my LM-2 wide band system.

[Qingdao]

Oh yes, this is the ignition I shoulda been running from the get go. Totally tunable, I can adjust ignition on the fly with the retard nob. It lets me go full retard or just a little retarded.

I was full retard with the locked distributor; and we all know "you never go full retard". LOL





The MSD does provide LOADS of spark too. Doesn't really help much power wise, but starting is like 1 000 000 times faster.






I also gave my little box 'o' small blocks a nice hair cut.

[paulofto]

Love the Tropic Thunder reference!!

[Qingdao]

Nitrous, its the word of the day. LOL

Its being all kinds of obnoxious installing this thing.

One I am quickly running out of head room. A while back I decided to re invent my square bore adaptor for the M90. It meant bolting another adaptor to my already bolted on adaptor for the M90. Great solution if the nitrous fogger wasn't a square bore only design. SO now I'm stuck with HAVING to run a square bore adaptor and a nitrous plate. Oh well, if I need more head space I can always "squanch" my cold air intake a little bit.


Second challenge for nitrous is getting a suitable bracket made up for the solenoids. My coolant reservoir has been, over the past few months, moved to just right of the carburetor. The front and left side of the carb are dedicated for throttle and vacuum lines. The rear of the carb is the ignition (I'd rather not have fuel lines running right on top of a distributer). Which leaves me with almost no room for the solenoids. I might just have to get a little crafty and tuck the solenoids under the coolant res.



And now the obligatory pic for attention.




and for those who notice, yes the engine is out of the car. I mucked up too much on the last block and bought another $100 block off ebay. its getting done up at the machine shop right now. Honestly I'm not too mad about the whole thing. Blocks cost $100 and machining costs about $350 for just about everything you could want done to it. Hence I'm gonna run nitrous and keep blowing them up.

[Qingdao]

Got my nitrous solenoids mounted to the flat bar around my carb. I'm about 70% done wiring. The triggers are feed into the cabin, but I haven't powered them.






And I wired my little fuel tank in the trunk with separate fuel pump. I'm thinking of just using aviation fuel in the NOS shot. But I might just toss in some ethanol free 93 octane fuel.







Hopefully all this is making Steve McQueen smile in his grave. LOL

[Qingdao]

Here is the subframe, trying to give others some clarity with my design.



https://www.youtube.com/watch?v=SHZz9yo35nw