The Stovebolt Site Forums The Shop Area Engine Shop Re-jetting carb for Clifford Intake-235 chevy

With the clifford intake for the 235 re-jetting is required..
How exactly is that done?

Thanks,

Keith

The nuts and bolts of rejetting a carburetor depend on the carburetor you have. The generic answer is that you get larger main metering jets for your carburetor, then disassemble the carburetor, remove the old jets and install the new ones. Depending on the carburetor, you can often do this by only removing the top (bowl cover), without removing the carburetor from the engine. You should have more than one jet size, so you can try different sizes until you get the performance you want. No matter what you do, check the spark plug color after driving a short distance (25-50 miles or so) after each jet change. A good color for spark plugs is off-white or light tan. Bright white porcelain may indicate that the fuel mixture is too lean- larger jet is required. Dark tan/brown/black spark plug color indicates the fuel mixture is too rich- smaller jet required. If your carburetor has metering rods, they also (sometimes)come in different sizes, to permit changing the power mixture. Metering rods slide into the main jet and restrict its opening for light-load operation. Main jet size is identified by a number stamped on the jet- larger number means larger jet. In the past, it was common practice to drill the jets to a larger size, but that is not a good idea.

Also, when you are driving the vehicle after the jet change, listen for detonation (spark knock/pinging) both at light throttle, and at heavy acceleration. Detonation also may indicate that the lean fuel mixture is too lean. Before you make any changes, listen for detonation and check the spark plugs, so you know if your jet change caused something that didn't exist before the change.

I'm assuming you don't have access to a chassis dynamometer and an exhaust analyzer. If you do, life will be much simpler.

Keep in touch.

Harvester

Harvester..that's quite a detailed answer. Yes I forgot to mention the carb would be a Holley 390 4 barrel. I believe Clifford actually makes a suggested jet sizes.

Thanks very much-

Keith

Start with their suggestions or with the jets sized for an engine of similar displacement. Fortunately Holley parts are really easy to get.

Keith,

If you haven't gotten your carb yet, get the Holley 390 CFM. Holley has this aftermarket stuff down to a science. The carb comes with a DVD that is PACKED with useful info on understanding your carb and goes into great detail about re-jetting.

They spell out in a very simple manner how to determine the correct jets and how to change them. A complete set of jets will set you back about $50 so you'll be able to dial in exactly what you need.

My truck is about a year from being streetable so I can't tell you any first hand experience but I can tell you that determining the correct jetting and installing them isn't high on my list of "anxiety inducing" what-ifs list.

Thanks 4

Chez-Sounds like you have the Holley intake? Yup 390 is what I had in mind...What are you doing for headers?

Thanks,

Keith

here is a installation manual for the holley 390 (ive been looking at getting one also for my clifford intake). it goes into a little detail about rejetting the carb but not much

http://www.holley.com/data/Products/Technical/199R8108-2.pdf

excellent read drummin-

thank you

keith

Fentons

The DVD that comes with the carb goes into detail and shows you how to change jets... with video.

czech-Did you buy direct from Holley?

TX

Keith

No, I bought from Jim Carter but never again. It came wrapped in bubble wrap in a box with the other $2k worth of stuff I bought. When I called to ask where all the plugs and caps were and why it was loose in a box I was told that's how they come.

BS... Holley carbs come in Holley boxes with all the parts. I get p1ssed just thinking about it and it's the main reason I don't deal with JC any more.

Whoever you buy from be sure they ship in the original box the way they are SUPPOSED to come.

Im getting mine from summit when the time comes, I buy alot of parts and such from summit and i always have good luck with them, and its really quick too, out the door sometimes the same day and at my door in no more than 2 days.

I've been in contact with Larry at Clifford-he suggested Summit for jets although he said they were readily available-

Czech and Drummin-do you have a source for the carb linkage-I believe we need to convert to a back and forth motion as opposed to the existing up and down?

Keith

I might just try to adapt a modern cable pedal, but thats just a thought, as im still waiting for my intake to be delivered and for me to order the carb, but its never to early to start planning things out.

Larry also states that there is a universal over the counter fix for the linkage-He used to sell it not sure if he still does

K

i like this setup,

http://www.lokar.com/product-descriptions/eliminator-fm-throttlepedals.htm

http://store.summitracing.com/partdetail.asp?part=LOK%2DFMG%2D6098&view=1&N=700+4294847984+4294891681+4294847971

a little on the expensive side but it will make for a very clean setup, then all i need to do is run the throttle cable up along the firewall and loop to the carb

That bridge hasn't been crossed yet so I'm open to suggestions on how to maintain my stock pedal and get the job done.

Hey, Keep me posted as well. I also wrote to Clifford and got a response saying that a stock linkage was available. There were no details though. I still have the stock pedal and pivot crank on the side of the block. What I haven't figured out yet is the connection from the crank to the carb. If anybody has done this and has pictures, they would be appreciated.

Todd, why not write back and ask for specifics.

The Holley DVD shows a couple different kinds of cable linkage they offer, but it's for newer cars. You would think with the limited number of carb options, and their manifold being used on specific engines that Clifford would have a market for linkage.

This is one thing that hasn't changed since the dawn of hot rods... carb linkage. It's always been a PITA.

This thread has really developed legs-Just goes to show if your in need of info on a subject...your're probaly not unique

I'll see if I can find it but Clifford gave me the actual P/N a year ago(for the linkage) It was inexpensive as I remember..Maybe it was that cable setup.

If it's helpful I have an e mail address for sale/help at Clifford.

Have fun guys...Good weather is almost here...Time to get crack'n

Keith

I have Clifford manifold, Holley 390, and Clifford long tube headers on my 235. I will get some pictures of the linkage as soon as I figure out which computer they are on.

Jetting: You really need to get the truck up and running before you worry about it. Holley does a good job of setting these things up from the factory. It will be close right out of the box.

Since I am a little anal retentive about these things I set my headers up with O2 sensor bungs for use with a wide band oxygen sensor. My truck is running but not drivable yet so have only checked the idle settings. My carb was dead nuts perfect in the idle circuit right out of the box.

Later,
Paul

Take a look at the StoveBolt Tech Tips:

Specifically: http://www.stovebolt.com/techtips/4bbllinkage.pdf

This is very similar to what I did and will have pictures soon.

Paul

Thats where I seen that!

I remember looking at that page a few days ago when I was thinking about how to set up the linkage and i completely forgot where I seen it.

I think I still might go with the cable setup, to me it looks like it would be cleaner and in my opinion, more reliable (but thats just me.

looking forward to the pics Wisner

TX

Keith

We bought rebuilt 390 from Larrow & Sons (chevyhotrod6_serrahost_com) already set up for 235 (~$250 in 2006).
Running 390 on Cliford intake w/ Clifford headers.
Figuring out carb linkage was a pain in **** , still working onkick down linkage to Powerglide.

Good luck

That's a nice service--setting the carb up..

I found the e mail containing the Clifford linkage p/n-
I'll post it when I get home..

Keith

found this response from clifford relative to thier linkage accessory...

"08-2428 is the part #. $19.00
It will click right on your standard linkage."

Keith

Thanks Keith,
Is there any info on this on their (or any) website?

no..kind of odd..no mention of it there..
But they have a P/N...

Must be pretty simple for $19.00

Keith

I'll bet it just an adaptor to hook a stock Holley cable linkage to the Chevy bellcrank.

A phone call is in order here.

Seems to me it would have to convert up-and-down motion to back-and-forth motion and it seems reasonable that that could be accomplished by altering the belcrank..

Be sure to report back if you call Clifford-

Keith

Guys,
The Clifford is bolt patterend for the old 4 barrels, correct? Need an adapter for Holly, Q Jet etc - more modern carb?
Cavebull

Also, any grinding involved with the clifford and fenton install?
Larowe and Sons say buying all from them they will match them up on a mock up head so you dont have to do it. Just curious cause I have purchased from differnt folks and want to know what i am in for.
Thnaks,
Cavebull

Sorry to take so long but couldn't find the pixs and had to flash some more.

I've parked the pictures here: http://www.whcinc.com/Scooter.htm

The linkage works correctly - closed to full open and no hangups. What I can't say is how it feels to drive since the truck is not driveable yet. Feel may be too heavy or light for comfortable driving.

Paul

Here's the deal on the throttle hook up.

I spoke to Dave at Clifford and they no longer sell 08-2428, but he gave me the number for Lokar (sp?) and I spoke to Vince over there and he told me that they make a throttle cable assembly that does the job. It's part number DP-1000HT and it can be bought from Summit Racing.

Here is the LINK

No, it's set up for an adaptor, and you will need one for your particular carb. Mine came with the adaptor when I bought both carb and manifold from JC.

That's what I've heard. Supposedly the bosses on the intake and exhaust are not the same height so the clamps don't ride correctly. If that's the case there might be grinding involved, or a spacer could be welded to the clamp...

I too am interested to hear more about this.