Holley 9022 800 CFM base plate?

[cadunkle]

I have a Holley 9022 800 CFM DP on my 454. The base plate is worn creating a small vacuum leak around the base plate that randomly wants to leak or seal... Causing all sorts of grief idling and around the docks.

I was considering getting a kit to bush the plate but that cost almost as much as a new base plate and I'd hate to not ream it out straight. Forgive my ignorance but is there any difference to a marine base plate than a normal automotive 4150 base plate? The 9022 specs on Holley's site mentioned sealed throttle shafts. I don't see any reference to the 9022 carb on Summit or anywhere else I've looked at base plates. Does anyone know is a standard 4150 DP Holley base plate will work? Any advantage to go with a Proform or similar aftermarket base plate if a standard 4150 plate works?

I called Holley today and they didn't have an actual part number for that specific base plate but could get me one, though they likely don't have any in stock and it would be made when they get around to another run of those... Up to a month before it would be made and shipped out. I asked if this part was interchangeable with a standard 4150 DP plate and the tech wasn't sure.

I asked Proform if their 4150 DP base plate would work and they couldn't tell me for sure either way, said to ask Holley.

I'd prefer to get this fixed quickly since my season has started, but don't want to spend $500 or more on a carb when all that's worn on mine is the base plate. I may rummage through my parts carbs to see what I have and what I can compare it to. If anyone has run one of these carbs and can tell more than I've found so far, that would be great!

[cadunkle]

Well I don't want to wait over a month for Holley to make one for me, so I went ahead and ordered a Proform billet 4150 base plate and a rebuild kit for the carb. I have some metering blocks to convert it to 4 corner idle, but not sure it's worth bothering. Engine is stockish and should be no problem to idle nice on a 2 corner idle circuit once this vacuum leak is fixed. Hopefully the Proform fits! If not I guess I can order the Holley and use the Proform on my truck.

[beast 496]

The base plate I believe is interchangable but the throttle plates are not. I really don't get into auto stuff. But the Marine version throttle plates have several seal groves which eliminate burn out while burning, part of the coast gaurd approved carb. I think the auto version has a plastic bushing for the seal. Al

[cadunkle]

What do you mean by seal grooves and throttle plates? I don't see how anything could burn out in this area to allow a fire outside of the carb? I guess I'll see the difference when I putt the carb apart.

[beast 496]

The grooves are there to control a backfire from igniting any fumes in the bilge area. The throttle shafts should have two to three groves or ridges cut into the shaft. Is your carb original? I did not think the PCM 454 had a double pumper 4150 style carb but rather a 4160 primary pump vacuum secondary.

[cadunkle]

No, previous owner rebuilt it in 2007 and did some performance improvements during the rebuild. I now understand what you mean about the throttle shafts. I don't think any fire would get through a normal shaft? The clearance is very tight normally.

A new automotive base plate would certainly seal in a backfire a heck of a lot better than my worn out marine version. I'll have a look on disassembly at the actual shafts and see what the difference is. If it's substantial maybe I can use the marine shafts in the new base plate, if the old ones aren't worn out.

[cadunkle]

Well I got the Proform 4150 base plate. Rebuilt the carb and put the base plate on. It looks darn near identical to the Holley 9022 base plate. All ports for the main body are in the same locations. Installed on the boat and adjusted. Idle seems much improved, smoother and more stable. It starts much easier now too, when hot just tap the key. Exhaust smells much cleaner too. Smelled very rich previously at idle and lower speed cruising.

I changed a few things around on the carb, but will need to fine tune on the water. The carb came out with jetting of 80 primary and 82 secondary, with a 4.5" PV on primary side and a plug on the secondary side. Also had 50cc accelerator pumps on both sides. Factory jetting is 72/87, 6.5/plug PV, and 30cc/50cc pumps. Also interesting is on the bowls jet numbers were written in marker, I forget what was on primary side but 88 was written on secondary side.

So the jetting basically seemed really rich on the primary side, with enrichment coming in later. The secondary side seemed really lean with 82 jets and no enrichment. No idea what the previous owner was trying to accomplish with this, the whole thing was set up goofy, backwards, and seemingly randomly. I changed primary jetting to 76, used a 6.5" PV, and swapped to a 30cc accelerator pump. Secondary side I kept the PV plug and 50cc pump, but changed jetting to 87.

I think this should get me in the ballpark and I may even be able to go a bit leaner on the primary side. I'll have to do some tuning on the water to find out for sure. Even if I can't go leaner but it'll take the 76 jets and 30cc pump I should save a noticeable amount of fuel. A day on the water of 6-8 hours of mostly riding has been costing me 36+ gallons. With proper tune I may get some more MPH out of it too. Only got 47 MPH last time I ran it wide open on GPS. I'd be happy to get at least 50 MPH.

So I thought I'd share this since you guys seem interested to follow projects and such, and maybe this information can be helpful to someone with carb issues. My next time on the water may be just a test & tune, but I'll bring tools and carb parts as well as my gear to ride if its more than just me. :D