Edelbrock Performer vs Thermoquad...

[Acesneights]

I could try another insulator. I have a speadbore style one between the adapter plate and intake.\nI could put one between the adapter plate and carb.. Friggin carbs gonna be touching the headliner...

[Acesneights]

Ok. The plot thickens...\nHad a good long talk with Summits tech dept. it is so nice to talk to people that k ow what they are talking about and not some worthless call center in India. He was well aware of the problem as well.\nHe recommended tossIng the spreadbore adapter and using a 1 inch phenolic spacer.\nBasically the problem is that the Edelbrock is an aluminum body carb and gas boils at 150f. This was not as much of a problem years ago but the crap gas with ethanol is causing alot of it.\nTravcos have zero airflow in the doghouse so the manifold heat has nowhere to go but up.\nThe thermoquad is part plastic so it does not have this problem. Its funny because I was thinking about a bilge blower\nOff a boat and he said the same thing. An aluminum intake and blocking the risers would also help but I wasnt looking to spend a ton of money on upgrades when the long term plan is a Cummins swap.\nSpacer will be here probably sat or monday so I'll report back .\nUgghhhh.....

[Acesneights]

Well the 1 inch spacer did not fit the bolt pattern of the manifold and despite what the tech from Summit said, the spacer could not be modified without compromisinnthe intergrity. I ended up getting the heat insulator that Edelbrock speciffically recommended for it part 9266. It made little difference if any. The only thing left to try is lowering the floats a little otherwise this carb is getting shipped back and i will have the thermoquad rebuilt.

[77Travco]

Or just go for it and order the aluminum intake... You could always craiglist the speed parts if you ever do the Cummins swap.

[Acesneights]

Well...I spoke with Edelbrock again today. There attitude basically was live with it.\nSo...it's going back to Summit for a full refund. I was going to rebuild the Thermoquad but I talked to a trusted Carb Builder on Long Island NY and said he had a few reman Holley spreadbore direct Thermoquad replacements on the shelf. 299+ core. It already has the correct linkage for Mopar and the body is not Aluminum. He assured me it will solve my problem. He did not like the idea of the thermo quad on the motorhome because the plastic bowls can crack and ...fire.\nUggghhh...\nI can say this. I would not recommend the Edelbrock Performer for this application. When I Google Edelbrock Performer and Heat Soak alot of hits came up, all confirming what I am experiencing. I think it's just a combination of ethanol mix and the fact that the engine compt has no air flow.

[Acesneights]

Holley Spreadbore got here today. Looks impressive. The body is made of die cast Zinc so it supposedly much better than aluminum for heat soak issues. Unfortunately I could not test it today as the waterpump won't be here tomorrow.

[Acesneights]

Edelbrock vs Thermoquad...And the Winner is....\nHolley Spreadbore.\nGot the carb on. It was a PIA. It required moving the Ignition coil and I had to use studs vs bolts. The bolt by the accelerator pump took 5 mins alone. It is near impossible to get a wrench on and you have to start 2 of the nuts while holding the carb up 1/4 inch. In fact on the rear bowl drivers side I had to file the bowl down a little for the stud to even work. I could not lower the stud anymore without having enough for full contact with the nut. All the while I'm thinking, it ran pretty good with the Edelbrock except for the gas smell.\nwell..night and day. It even sounds better. Like a deeper sound idling with more throat. It accelerates much better which was surprising from a Vacuum secondary carb vs a Mech secondary. I got it good and hot and as it sits outside...and I type this...I wait to see if there is any fuel perculation going on...If not...I got a winner.\nHow unfortunate they no longer make this carb. They still make the 4175 which is the Holley spreadbore replacement for the Qjet. I wonder if the bolt on Dodge throttle linkage bracket from the edelbrock would work ?\nI want to send a special shout out to my freind Jim at Allstate Carburetor in Long Island NY. Great Job on this carb...(Now I sound like John Taffer from Bar Rescue...lol).\nhttp://www.allcarbs.com/\nI have used him in the past and have a great track record. He did not even bust my balls when I called him after I tried to start it and gas was pouring out of the top....\nYep...common Holley mistake. I hooked the fuel line up to the bowl vent. I did catch though before he had to tell me so that saves some face for me... \nSeriously...He hooked me up on this thing. So far so good. Even if I get perculation, It still runs much smoother than the Edelbrock.\nI'll try and get the numbers off this carb if anyone wants to try and scrounge one of ebay for a core. I think it was 7448 but let me double check. The linkage lined up perfectly. Even better than the Edelbrock with the adapter. The tranny seems to shift better. I think the geometry of the Edelbrock adapter was wrong because I could not get the tranny to shift right.

[Acesneights]

well...still got some gas smell. Not as bad but it is there.However the good thing is that it started right up with no vaporlock so that is good and overall sounds and runs much better. I guess the gas smell is something I'll have to live with. Thanks EPA for Ethanol mix. Maybe a bilge blower ?

[77Travco]

I have to say... My coach dosen't have a "gas" smell, but I do get a general oil or engine smell after I have been running it.\nGood information here... After reading this, I may rebuild my carb someday instead of just buying a new one. (but it works fine for now)

[Acesneights]

I think the cast iron manifold is part of the problem as well. If I come across a decent priced aluminum I may swap it and block the exhaust ports at the same time.\nI did not have any gas smell either with the TQ.