Inliners International Forums General Discussion Engines 292 engine temp due to bypass hose

Hey fellas,I asked a similar question earlier and never got a response but I'm running a 180 degree thermostat in my engine and it never seems to get to full operating temp.Now I'm going by my gauge and how it read with my 250's and not by a thermometer.....yeah I guess i should check....but anyway have any of you had the same problem with the bypass hooked up.I would run a 195 thermostat but fear that If my engine ever ran hot it would void my warranty because they have these little gizmos on the block so if it runs hot they'll know their whistler did.Well thanks in advance for any replies. Gerald

Gerald,

I don't think you'll have a problem if you put in a 195 t-stat and try it. I run 195's in all my vehicles and also use an electric fan setup with the 292 equipped '63 pickup. The controls are set to turn the fans on at about 220 and turn them back off around 185. And running the truck during the summer here in the Phoenix area means the fans are on almost all the time setting at stoplights. The "tell-tales" that the rebuilders use won't do anything until about 260 to 280 degrees. Basically an engine won't get that hot unless you are running it without coolant.

If the 195 doesn't change the temp that your engine runs at, then get back here and let us know.

------------------
David
newbie #4153

Hey thanks for the info Dave.Tell tales eh.....LOL.......I'm glad to know the temp they tell on us for sure.My engine hasn't gone over 200 degrees but I was getting woried that if it hit 220 the telltales might get my warranty.I'm gonna try the 195 to and see how it does.Take care......Gerald

Hi Dave,
I too have a 63 Chevy truck and plan on upgrading the engine (stock 230) to a warmed up 292. I've been reading about the manifold heating issue in regards to air/fuel ratio and its effect on drivability. My plan is to add a Clifford 4bbl manifold,(the one I have doesn't have the water box)with a Qjet, and Borla stainless steel headers.
Do you have any insight on running a Qjet and do you know of a way to add heat to the manifold I have? Any info or leads would be a big help.

Thanks for your help, Gary

I can only speak from personal experience of using a Q-jet on a Offy manifold. They have a square bore in the center of the bolt-down holes and must use an adapter plate to actually connect the carb to the manifold. Using a Q-jet requires another additional adapter. Those things have sloped sides in order to make the spreadbore narrow down to the square bore. On a 6-cylinder, that spells death to proper fuel distribution. The sloped sides cause the air to turn extra corners and induces too much turbulence.

If the Clifford manifold is available with a large enough hole to not require the use of an adapter from spread to square, then go ahead and try it. Otherwise, don't bother. Hope this helps your decision.

------------------
David
newbie #4153

Thanks for the advice David. I do have a Rochester 4Jet square bore carb that would probably work better than the Q Jet/adapter set-up. Any ideas on the manifold heat issue? Leo Santucci's book says that the heated intake is an absolute must for a street driven engine. I live in San Diego, so engine warm-up dosn't take very long, if that is the issue. Thanks again for your help. Gary

I remember those old 4-jets. I bought a 68 GTO that had one of those retrofitted on it. I ended up taking it off and putting on an AFB because it wouldn't keep from flooding the engine. As long as you can bolt it down on the manifold, and the carb is sound, then it should work great.

However you do it, get some heat under that manifold. Engine warm-up is not the issue. It all revolves around fuel atomization / vaporization / CONDENSATION problems in the manifold directly under the carb. Gasoline coming out of the venturi nozzle is in very small droplets. There must be enough heat in the manifold to vaporize it so it can burn in the cylinders. If you don't have heat right away, the physical reality of the air becoming colder as it goes through the carb will cause some of the gas to collect in a puddle in the manifold (flooding). It's nothing but thermodynamics in action. The air has to become colder because there is a big pressure drop across the throttle plate. If you are only operating the engine at wide open throttle, then the pressure drop, and the accompanying temperature drop, are minimal. In addition, the velocity of the airfuel mixture is high enough that it has no chance to stagnate and puddle out. That's why you can get away with no heat on a drag race motor but not a street engine.

Call Clifford and see what you can find to help the issue. And good luck with your project!

------------------
David
newbie #4153

Thanks so much for the info, Dave. I've already bought the manifold without the water heat box, so I'll have to make something that will provide the needed heat. A stainless steel box with a couple of in/out fittings should suffice. Thanks again, Gary