carburetor switch

[Mike Armstrong]

Speedway Motors carries some nice ones too. I plan on their chrome oval. Mike. any progress on the carb swap?

Took a few hours but I got everything installed and reattached Saturday so should be ready to go. One thing I’ll take a second look at is the wiring to the coil. Not sure I was getting the full 12v during cranking which could account for the previous hard cold starts.

I’m going to look over the set up DVD then give it go next opportunity, thanks.

 

[Mike Armstrong]

My stock 2.8 (Jose headers, Duraspark II) with the stock 2150(A), despite a couple years of ‘fixes’ (Manual Metering Block), tinkering and brain drain, still left me with difficult cold starts, rough and fluctuating idle, and throttle hesitation.

Without any carb adjustments (before installation I replaced the #61 jets for 57’s per Jim) and on a dead cold engine that hadn’t ran for a few weeks, I had a brief chance to hook up a weak battery just to see what would happen, if anything. The first crank of the engine and it started right up, which I hadn’t seen that engine do when cold in a long time, and the choke kicked into high idle. It already sounded better than before. After a few minutes it kicked the rpm down and at operating temp I tapped the throttle into a 900rpm idle, which I lowered to a pretty smooth 800. Checked the throttle response, no hesitation at all. Overall, I’m very impressed!

Next chance I get, I’ll set the float level and adjust the mixture screws which should improve things even better.

It’s good to know both the Weber, and Holley carb swaps are easy and work out quite well.

 

[260Alpine]

Mike, Great News!

 

[Mike Armstrong]

Just some quick pics for future ‘switchers’ reference and to compare with Steve’s great example of the Weber mounted onto the 2.8. Both are viable options and allow for great clearance.

https://photos.app.goo.gl/1QMVB98vLqYgXg7u6

 

[260Alpine]

Mike, Where did you get your K&N type filter element?

 

[Mike Armstrong]

Mike, Where did you get your K&N type filter element?

I believe it came with the filter housing.

 

[wile coyote]

Runs great with the Weber 38 457 kit straight out of the box. Very smooth acceleration. Starts great. I'll post pictures once the air cleaner is here.
75mph at 3000 rpm, stayed right at 205 degrees. Really sounds good.

 

[260Alpine]

Wile, You are doing a great job on your car!

 

[Mike Armstrong]

Runs great with the Weber 38 457 kit straight out of the box. Very smooth acceleration. Starts great. I'll post pictures once the air cleaner is here.
75mph at 3000 rpm, stayed right at 205 degrees. Really sounds good.

Good to hear Wile!

I checked the Holley float level and it was spot on, adjusted the mixture screws, couldn’t get any better than what they had been set at. This is good news for carb switchers that want an out of the box, ready to go, bolt on solution. Whichever your preference, both Weber and Holley apparently work great.

Funny, but, now I get a kick out of walking out to the garage in the morning and turning the key on a cold engine just to hear it start right up, simple, but after a couple years it’s a welcome new experience.

 

[260Alpine]

Mike, Great! Have you driven it around town and freeway to give us a review? Check your plug color to see if jetting is spot on?

 

[Mike Armstrong]

Mike, Great! Have you driven it around town and freeway to give us a review? Check your plug color to see if jetting is spot on?

Haven’t had a chance yet.

One other thing I need to check is the adjustable vacuum advance. That was pretty straight forward when I had to connect to manifold (the 2150(A) did not have a functioning timed vacuum port), but now that I’m using the timed port on the Holley I need to see what it’s doing above idle and out on the road. I’ve read that getting that proper balance between base, vacuum and mechanical adavance is a lost art.

 

[260Alpine]

Mike, Your vacuum advance will be the same except for idle. With ported you will have no vacuum at idle. If you hook up to manifold vacuum your idle will speed up and you will have to slow the idle speed back down. The benefit of manifold vacuum is smoother idle, sharper throttle response, cooler running at idle. When you give it gas the vacuum drops off.

 

[Mike Armstrong]

Mike, Your vacuum advance will be the same except for idle. With ported you will have no vacuum at idle. If you hook up to manifold vacuum your idle will speed up and you will have to slow the idle speed back down. The benefit of manifold vacuum is smoother idle, sharper throttle response, cooler running at idle. When you give it gas the vacuum drops off.

So, now that I have a functioning timed port it would be better to remain on manifold? (from past experience of reading about this subject on the internet, I know this topic is a potential can of worms ) But, I do trust your advice.

 

[260Alpine]

Mike, I like manifold vacuum better as stated above. There is a small manifold vacuum port capped low on the carb. You may even get slightly better mileage in city driving. It will also help on overheating if stuck in traffic jams. You will have to slow down the idle speed. Try it and compare. The key is you have to limit the vacuum advance to 8-10 degrees which you already have done. Pre-smog specs. A lot of ported vacuum advance cans have 14-18 degrees which would be too much at idle.

 

[wile coyote]

Done!!! (For now) k&n air cleaner for weber from Summit. Fits great. I removed the weber to 5 1/8" filter adapter that comes on the 457 kit to put the filter directly on the weber.

 

[260Alpine]

Wile, Very Cool! Like the big pics too. You do know you are never finished!

 

[wile coyote]

Yeah, I think I'll go through rear end this winter.

 

[Mike Armstrong]

Nice Wile!

 

[pcmenten]

I cut down the upper part of the intake and had the lower EGR passage welded shut. Lowers the carb by an inch. It’s close to the valve covers but it clears.

I’ve got an assortment of 2100 carbs to try out.

Paul

 

[260Alpine]

Paul, Love those Euro valve covers! The Autolite 2100 is a great carburetor too.