Turbo carb selection...

I am actually not working on a bike, but rather a small car engine. I
am turbocharging a MGB with a 1.8L engine, but hear me out for a
minute. I had planned to use a Weber DCOE carburetor, but they have
become very hard to find so I am looking for something else that will
work. Mikuni carbs came to mind. There are few new carbs being made
these days for cars, but these motorcycle carbs are modern and
beautiful. There are no throttle shafts in the slide design, so that
is one less thing that can leak boost. What do you guys think? I
know Mr. Turbo uses the Mikuni HSR in those turbo kits. Is that the
best Mikuni for turbocharging? I think even one HSR 48 would flow
enough for this engine. Or maybe two HSR 42s. What other carbs
might work for me? Has anyone had experience with turbocharging
Mikunis? Any information would be greatly appriceated.

Thanks,
Tim

 

Sorry I can't help, but I have some input - I had 2 MGB's, a '63 and a
'78, and I hate them even now as I write this. I would stay stock, as
my '78 had a single Weber, and it NEVER RAN CORRECTLY. MGB's are really
cheap, and I mean cheaply made, shoddy crappy awful workmanship, and
just English pieces of S***.
No offense, but what do your friends think about this?
I remember the brake reservoir; it looked like a redone soup can! To
unlock the optional/aftermarket wire wheels, the manual said to loosen
the knockoffs, and drive slowly in a circle - it worked...I remember
Moss Motors, taking yuppies' cash and preying on their
sentiments...geez, I've been in an old Yugo once, and it was probably a
better car.
Again, no offense, and each to their liking, but your post surprised
me...

 

The problem is that you have to select carbs that will be able to richen
the mixture enough and have enough flow. If you start really pumping the
air into the engine, then you have to have enough gas too else you will
have detonation or knocking. Engines don't last very long when they
detonate. I have seen pistons holed in less than 10 seconds due to
detonation. Getting that mixture right is critical. I would ask an
experienced tuner for help with proper carb selection. i would also have
him set it up.

Be careful with the boost. My son cracked his engine block when his
modified wastegate failed. I think what happened was that he miscounted
the turns on the adjustment screw thus bottoming it out. He essentially
had no wastegate at all for that final run. 1 week and one engine later,
he was back running. He never did tell me what that mistake cost him. It
wasn't cheap.

Good luck.

rj