Motor Home Mileage

[Chuckles]

Thank you Steven, good job on the photos.

The link was great, A little more info gladly gleened for the beast.

I am going to try and remove the plate, after copious amounts of WD40 or Plus-Gas to free off the bolts, don't want them snapping off!

As it seems unlikely to replace this part I will attempt either a repair or a modified adaptation. I will let you all know if I am successfull

Chuck

[GlenCoombe]

Chuck, you might also check your speedo/odo with a hand held GPS. Hope you find the solution for your carb woes. If you can find a carb technician who knows his stuff the difference, as in my case, is worth more (much more) than the cost of an overhaul of the carb.

[Chuckles]

Glen, I am still in a bit of a quandry about the carb, does it stay or does it go (Fuel Injection or Holly replacement).

but I take your point and I think once I get this repair sorted, and this next weekend out of the way, then I will have a week or two 'breather' to have the carb properly sorted.
Chuck

[GlenCoombe]

Chuck, many have pointed out in the past, on this board and on RV.net that the original Rochester Quadrajet, in good original shape, is the best carb for the job. Fuel injection is great...at a price. The Holley family is a great performance add on but the cost vs. a simple rebuild of your existing carb may not be the most benefit for the $$...or Pound as is your case.
In my case the rebuild on my carb was the first. It had never been touched since new and had over 40,000 on it when I had it rebuilt.
I vote for a rebuild and a new electric choke assembly to replace the hot air choke. That should serve you well for the next five or so years.

[ALANSD]

I thought the Edelbrock replacements were highly recomended although pricier?

[Chuckles]

I attacked the hot air choke today.

As the gaskets had not arrived yet for the carb, that was left in place. This meant that the plate in the induction manifold could not be removed. SO.... I drilled out the rivets holding the cover in place over the bimetal spring of the choke. That cover could not be moved otherwise, and I needed to know how it works!
With an experiment with a match I could see the spring move to open the choke, that started me off on the correct way to adjust the cap.

The choke is now, as a temporary measure fully open. Its a blighter to start, a few pumps on the gas pedal before and during starting, and continued pumping in the first few seconds, then she's away and runs quite sweet. The tick over is much lower now, indicating that the choke was possibly holding on for quite some time.

I am happy in that I found a possible cause for the excessive fuel consumption, and a few trips will either confirm this or dash everything. I am assuming no air/vacuum is lost throught the manifold plate, and the pipe openings on the choke and the top of the carb are now blocked off. So it's all down to seeing how it performs.

There has been mentions of the electric choke, but I cannot find details of the conversion/kit.

Chuck

[GlenCoombe]

Chuck, make sure you're getting lots of cool air into the carb too. If you're still stuck with the original air filter and horn intake you can do better.
Click on my name and go to my photos for a look at the mod that made a great difference in my performance. Only took a few hours and simple hand tools to make... even got by without giving any blood, which for me is a small miracle.
BTW are you still also using stock exhaust manifolds? Headers will disapate heat and aid in low end torque while offering a modest gain in mpg. I've gone all the way from the motor back using Headman header, 2 and 1/2 inch pipes through Flowmaster mufflers...out via Chevy bowtie tips in front of the rear axle... sweeet sound and nice performance too.

[Chuckles]

Ah! now Glen you are going a bit fast for me!

Saw the air intake, yes that makes sense, so I will have a go on that.

As for the headers, that's a different story. Getting hold of that sort of stuff here will be a challange so I will do some research and see whats available. I will have to do something soon on the exhaust as there is that little rasping noise indicating a pin hole on the manifold.
Chuck

[GlenCoombe]

The stock manifolds are very prone to cracking and even headers require constant attention to torque of the header bolts. I do the "Tight'n up" every two weeks....actually that's about every 7-900 miles for me.
Over there I'm not certain what you'll find or pay so check out www.summitracing.com over here for Headman's and Flowmasters. The Flowmaster mufflers where a big surprise to me as they are VERY heavy. Built to last but a little dear on shipping...
Follow this link to my friend Scott's rebuild site. http://www.picturetrail.com/clubmaxxpch . He developed the remote air intake I copied. His rebuild will make you think you've bought a palace.
BTW I'm of the opinion that Scott never sleeps. I am his National Sales Manager and a very big fan. Check it out.

[swebster]

I thought the Edelbrock replacements were highly recomended although pricier?

Alan, those are very nice. They are not much more than a nicely rebuilt QJet.

Chuck,
I second Glenn's notes on the headers and exhaust. I did the same modification and am very happy with the results. I too had a failing manifold (actually the AIR induction system was failing not the manifolds themselves) and the headers, pipes, h-pipe and mufflers cost me less than replacement AIR manifolds.

[Chuckles]

Well what a disaster.. .... You may recall I disabled the choke by removing the pipes that fed hot air from the inlet manifold to the bimetal coiled spring...... so far so good. It started and ran (vehicle stationary) quite well...considering.

Then we set off a week later, with a full gas tank and water tank to our Country & Western weekend, about 20 miles away! Thank Goodness........

It just about made a 1:80 incline! It coughed and popped; you name it did it, very embarrassing holding up the traffic. I just could not make out what I had done - or undone.

We arrived, had a few jokes about 7.4 litres of engine doing 5mph and settled down for the night.

Then EUREKA! At 3:30 am I remembered, I took off the vacuum line to the auto advance and retard to the distributor to make easier access! Derrrr!

Thank goodness the engine hood is inside… there I was in “me rudery” with the doghouse up and yes it was still off – the hose that is.

Well the journey back was better but it still doesn’t like the second stage flaps opening. As soon as the foot goes down,on a hill or whatever, it backfires back up in the carb. I gather reading other posts on this matter it is quite common, something to do with floats and too much fuel, or would it be timing? Bearing in mind our petrol (sorry Gas) is 95Octane and higher.

I now have the gasket set, so soon the learning curve will begin. I must admit this type of carburettor is new to me so “in at the deep end” I must go….

Chuck
Dorset UK

[GlenCoombe]

Interesting.... remember the old curse / blessing? "may you live in interesting times."

Seem you've had some interesting moments lately Chuck.... with more to come as you open that baby up.

Much as I enjoy the work I often leave the "heavy" stuff to my professional.... so I can go home and work.

Check out the tune up thread running for more fun in the engine bay.

[Chuckles]

Glen,
I am trying to select the header and exhaust I need, but have become totally confused. UK and USA terminology differs so much in this area!

I noticed looking down from inside the coach, looking at the back of the engine, that the left side (Drivers side) has the manifold almost bent back on its self to avoid the gear linkage, whereas the opposite side has this preheat valve in the flange between the header and the down pipe. PeterH-79MH and Guy 99 agree that it's a heat riser, which has been totally disconnected, but I dont know if it's open or closed! So it would seem that I need to replace the entire system to ensure compatibility. A flexible down pipe section springs to mind.

The part number gleaned from Hedman is 69126 with a dimension 13/4”, 3” as the tube and collector – what ever that is….

Does anyone who has gone through this route, on an 1982/83 310 have the part numbers handy both for the header and the exhaust system as a whole?

From the Hedman site with the headings year, engine, part number, gasket number, some footnotes and various other codes followed by the Collector and tube size.

68-95; 396-454; 69126*; 27550; 1, 6, 38, 42, 45; Y; Y; Y; Y; N; N; (A); 13/4", 3";

Thanks once again for all the help from the great US of A
Chuck

[GlenCoombe]

Chuck, I'd have to look up the part number from a while back. I actually called them and they sent me what I needed. The motorhome version of the big block Chevy Headmans are "universal" and I'd do away with the heat riser hardware. The dimensions are 1.75" tubes into a 3" collector.
I used Flowmaster 70's with 2.5" inlet/outlet. 3" is too big and the Headmans will come with collector reducers to go from the 3" at the header to 2.5 at the inlet to the tail pipe.
Are you planning to switch to an electric choke?
Of course when you order all this stuff if you're adding new exhaust pipe this all becomes a measure cut bent trial by fire routine.... but don't forget to order the Chevy bowtie stainless tips for the final touch! I have both tips exiting on the drivers side in front of the drive axle. The pass over for the curb side was some trial and error for my muffler guy who bent the pipes.