The Stovebolt Site Forums The Shop Area Engine Shop Setting Up the Offy and Holley Webers

Finally got around to fitting up the Fentons, Offy intake and dual carbs as well as the dual exhaust head pipes. Linkage is done and I made up a throttle rod to drive the Offy linkage from the original block mounted plate. Now to plumb the vacuum, Offy water and fuel lines. New pics posted at the link below.


http://community.webshots.com/user/geezer

Nice, nice lookin motor, Geezer. Really sharp. I'd be very interested in how you go about tuning and synchronizing the carbs and what kind of performance you get out of 'em.

49 geezer- make sure to seal the two plug in the offy before mounting it- They will leak sooner or later- If you use exhaust gas to heat the manifold you might not notice but will probably be inhaling carbon monoxide while driving.

Welding them up is the only way- either pull the original steel plugs and replace with aluminum or have a piece of aluminum bigger than the hole welded over it.

Great looking motor! I couldn't help but to notice the thermostat housing. The outlet appeared to be on the drivers side. Can you elaborate on that? I SO would rather have it that way. The outlets on my 261 housing both come out the passenger side so I had to do some tricky fittings. Is that how you're going to heat your intake?

Thanks everyone! NM, the plugs were already welded nicely when I got the intake from Tom Langdon. Had seen the previous forum notes about this problem earlier. Chevy, I'll be interested in the tuning also. Was suggested that I use a Unisyn gauge but not sure how it will fit over the carb body. Langdon suggested the infamous 3 foot piece of garden hose. Bigmac, don't know about the housing. Was that way when I bought the truck. I am using the aluminum adapter plate behind the housing that Langdon sells with the water outlet to the plate under the intake. Not quite sure on how I'm going to plumb it back to the system. May go around the front of the engine or to the rear and tee into the heater hoses. Whatever looks best. Also, bought a rebuilt water pump from a website that was original to the 261. Has two water outlets to the heater instead of one. Believe the extra one was for a rear heater in school buses. That'll be going on next after pressing the pulley mount further down the shaft and painting it.

I'd like to see a close up of that thermostat housing. It almost appears that you don't need that adapter plate if that is a by-pass housing. Did you see my pics? I may be biased, but it is the cleanest intake heating system I've seen so far. And it works well. It compliments the stainless fuel line and looks like it should have came that way from the factory. My motor(until next year ) is a 235, but I utilize the by-pass housing and pump from a 261 to heat my intake. This was recommended to me in this forum by 4onthefloor and it turned out better than I had imagined. However, both holes come out the PASSENGER side of the housing and I thought it would look even cleaner coming out the drivers side as it appears to in yours. That's why I would like to see a close up pic. My plumbing is 5/16" brake line with inverted flair fittings painted with chevyduty "stainless" manifold coating. You could probably use stainless tubing as well if you wanna spend bucks.

Bigmac;
Your plumbing does look very nice. I will probably copy some of your ideas. Think I will be doing it in stainless. My neighbor is pretty good with a bender and think it will loook nice. Will get you some pics this weekend of the thermostat housing and set-up.

Number one and most important is build quality throttle linkage, must work smoothly and be strong. Secondly make sure the throttle plates open exactly together. If one leads the other the slightest, you'll never get them to run right. And that 3 ft of hose really works. I've had the Holley-Webers for couple years now and they are super.

bigmac;
Uploaded a few pics of the housing installed on my engine and also one that I have as an extra one. Look in the miscellaneous section.

http://community.webshots.com/user/geezer

There are some interesting differences between your housing and mine. If I were to assume, I would say that you have the school bus set-up. It appears that that fitting that comes out toward the drivers side was probably for an additional heater since it is below the thermostat on the bottom half of the housing. I think my second fitting (on the top side of the housing)that comes out on the passenger side was the by-pass feature for the 2 or 2-1/2 ton trucks (non-school bus). If you'll notice, mine does have a third boss (also on the top part of the housing) that could be tapped and used. Maybe it's just a slightly different design from a different year. Maybe there is someone here that knows for sure. I don't know why you couldn't just use that fitting on your housing and eliminate that spacer you got from Langdons. Anyone???