I have a Holley 600Cfm Vac Sec on my Truck. 327 SBC. Its the type with the Crossover tube from the primary floatboal to the sec side. And it was spewing gas all over my engine past one of the little O-Rings the other day. ( it seems to go through these little O-rings faster than any other parts in a Rebuild kit.) So I could get another Rebuild Kit, just to get 2 more of these stupid O-rings... Or would it be possible to convert the Carb to a Dual Feed? ( Im looking at some Vac Sec Dual Feed parts carbs, and I'm tempted to snap one up if I can get it cheap enough ) Would the boals fit my carb? Or is there more to it than that?
Alex I have the same 600 on the Jag. Holley 1850. Use a dual feed primary bowl but longer correct bowl screws, Secondary metering block with no provision for power valve, idle mix and vacuum port. or.. buy Holley secondary dual feed bowl "no accellerator pump" (holley 134-102 ) about $40 at Summit. http://store.summitracing.com/partdetail.asp?autofilter=1&part=HLY%2D134%2D102&N=700+4294925239+400178+4294845247+115&autoview=sku I looked at this awhile ago. Also.. Since the 1850 vac secondary..you might need to go to #64..to #68 depending on metering block I had a 750 Double pumper that I was going to rebuild for the Jag..but the 600 is well big enough. I haven't had any leaking from the cross tube...so I kept it as it is. I had a nice fuel block/pressure set up for the old DP750..and thought it was easier to just go with the 1850..single feed...and ditch the fuel block dual feeds lines. I checked this out a few years ago now..but I think it's close..
What is the list# of your carb? If it's a #1850 you can use bowls from a #3310 (750 vacuum secondaries).
Pretty sure its a 1850. I already put a metering block on the secondary side after I used it for a while ( I bought it new about 10 years ago ) so I can change the jets and the Vac Secondary spring kit. Its a good carb, but that crossover tube is a pain in the ***... Thanks for the Info guys. I think I'm going to try that...
There is a new style transfer tube that uses seals instead of O rings. Also there are new type seals that work on the old transfer tubes. I don't have a Holley catalog here or I would look the part #'s up. You could search on Summit's site maybe...
In the Book Holley rebuilding and modifying by Jeff Williams he says to put a bit of petroleum jelly on the O rings before ***embly. He also says that you should be able to twist the tube with your fingers after the bowls have been installed and torqued in place. Years ago I put center pivot bowls on a carb that didn't come with them and it ran pretty well. I can't remember what the carb was now but think it was a 600 or 650.
I just bought that transfer tube and new seals for an old 1850 I have. I think this is the best $12 I have ever spent on one of these carbs.
I would love to see an improved seal on the tube for this very reason, but I do prefer the 3310 bowls and flexible dual feed lines so I can work on one side without concern for the other.
Ditto on that I ripped mine when I rebuilt the floats and ordered new o rings, just a little lube and push and twist, making sure that they stay on the inside of the tube flange. If pushed too hard they can come up on over the flange and not seal, ask me how I knwo that.
Put the o-ring on the tube far short of the dent. With some practice, as you insert the tube it will roll into place. Kinda like a condom when you are in a hurry.
I fixed all my leaking holley problems with an AFB and now I dont have to worry about leaks or if the secondaries are opening up.
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