Avanti misfire

[wagone]

Peter,

Your blower is reconfigured (repulleyed) to give 7.5 lbs of boost at 5600 rpm? Now that IS COOL! And you get by without an air box? But probably not for long as you occasionally blow seals out of the carb? I was interested in putting as air box on mine but there is PRECIOUS little room under the hood of an Avanti for the box.


wagone and the OLD R2 Avanti

[StudeRich]

Wagone; wouldn't the R3 front engine mounts help? If Studebaker did it, you should be able to! [^]

I have a set, just waiting to go into a R2 1/2 or R3 Avanti! []

quote:Originally posted by wagone

I was interested in putting as air box on mine but there is PRECIOUS little room under the hood of an Avanti for the box.

StudeRich
Studebakers Northwest
Ferndale, WA

[wagone]

StudeRich,

As I understand it the "thin" front motor mounts gain you a 1/4" and I need about an inch. I'm thinking that the factory raised the front body mounts (on the radiator support) to gain the extra clearance (course mine could be lower than most in the front--but I doubt it as my cutouts for the bumper support are exposed.....many are, it appears, and some are not). I'm thinking that a person could get about a 1/4" machined off the top of the intake but I'm still 1/2" short. I'm the guy that bought the air box JDP had advertised on this forum a while back (two months, perhaps--or less) and I'm probably going to sell it as I can't see how to make it fit (the bonnet on the R2s are about 6 1/8" high up from the intake and the R3 boxes are 7" tall). If I decide to part with it I will list it on this forum and for what I paid John for it--no more. I'm sure it could be made to fit (for instance cut some off the top half of the box), but I'm not one to modify things--especially, I wouldn't cut the box. As I understand it these boxes were made by Lionel Stone and from the original patterns......so the box at 7" high shouldn't be any different than original boxes.[?][?]

wagone and the Old R2 Avanti

[jlmccuan]

Plugs gapped too wide?

Jim

1966 Avanti II RQA 0088

[Karl]

Bob , Did you say your WOT AFR is 11:1.[:0] Your carb needs to be leaned down a tad. 13.7 is ideal most are set up 13.2. What do your plugs look like? Try gapping them about .030. As jim suggested to wide a gap will cause a miss.

63 Twin Supercharged Avanti
64 Avanti R3w/NOS
88LSC Avanti 350 Supercharged w/NOS

[fmarshall]

My guesses are timing, octane, belt slippage, fuel shortage at that RPM or valve float due to spring tension.

Somewhat off topic, re the air box, I read somewhere that an R2 standard carb can hold up to 18 pounds of boost when sealed properly.

I rebuilt mine just this weekend and I didn't even use double gaskets for the air horn to base and it handles the factory boost all the way to red line.

I was thinking of reworking the heads to R3 specs at some point, and was thinking of moving to a new Edlebrock and an R3 box. But after reading that, I decided to stay with the r2 configuration.

[Bob Langer]

I havent had a chance to check the plugs to see what they look like.
They are set at .035 and yes the AFR is 11-1.

What do I need to do to the carb to lean it out? I have been using Sunoco 91 octane or should I go higher.

Bob Langer
63 Avanti
Glenshaw,PA

[Lenny R2]

I have the R3 air box on my 64 Avanti R2.I also installed
the R3 mounts but had to install 2 washers on each side to
clear the reach rod on the steering.I installed the thick
carb gasket in side the box & 2 thin gaskets under the box.
with the hood closed nothing seems to rub.
64 Avanti R4442




w


Lenny
Atlanta Ga.

[gordr]

quote:Originally posted by Bob Langer

I havent had a chance to check the plugs to see what they look like.
They are set at .035 and yes the AFR is 11-1.

What do I need to do to the carb to lean it out? I have been using Sunoco 91 octane or should I go higher.

Bob Langer
63 Avanti
Glenshaw,PA

Bob, do you know what float setting was used by the carb rebuilders? If they set it to factory spec, it may run rich. Today's gasoline is a little less dense than the '60s brew, so floats don't ride quite as high in it. As a consequence, the fuel has to rise higher in the bowl to close the needle.

Try lowering your float level by 1/32", and see what your AFR reads at WOT.

Gord Richmond, within Weasel range of the Alberta Badlands

[Laemmle]

Use Sunoco race fuel, 110 RM/2.....with TEL

quote:Originally posted by JDP

Be damn careful your not getting detonation at full boost. Unless you are running racing fuel, you likely will if set to the factory specs. Todays premium is not much better then the 60's regular.

JDP/Maryland
64 Daytona HT/R2 clone
64 GT R2
63 Lark 2 door
52 & 53 Starliner
51 Commander

[Karl]

How did you get the 11:1 reading? [?]What is it at idle, cruise?[?] You will need a starting point.There was a thread on this some time back. That had stock R2 carb specs. metering rod/jets in it.(sbca is good at finding these things) Need to find out what you have . Then go from there.Both power and MPG will go up.

63 Twin Supercharged Avanti
64 Avanti R3w/NOS
88LSC Avanti 350 Supercharged w/NOS

[Bob Langer]

Three days of rain have stopped.I sanblasted the blower pulley and
dressed the belts.Just got back from road test and happy to say problem solved.Took it up to 5200rpm and never missed a beat.Might be more left but didnt want to push it.
Thanks to all who took the time to help, I really appreciate it.

Bob Langer
63 Avanti
Glenshaw,PA

[64Avanti]

The LS R3 air box is most likely not made from the origianl tooling. When we purchased the Studebaker stuf from Paxton Joe Granatelli said the air box pattern was missing. It showed up as part of a kit for a Dodge duster on the cover of a magazine a few months later. I still have the magazine. A long conversation was the result but he had our money and the tooling that we should have received.

We ended up making a pattern using an existing part. The parts we made were as a consequence a little smaller than the original parts. I suspect that Lionel Stone is still doing the same but don't know.

If that is the case then the air box should be a little shorter.

David L