New crate 454
Last month I broke the crank in my 1988 Winnebago Super Chief. It had only 57,000 miles on it. I located a GM crate engine 454. I took my time and installed the engine piece by piece. I went with a n...
Forum Discussion
Gale Hawkins wrote:
Not lot details but four options for 454. Note one base height is greater.
Long vs short could make a difference to do fan placement in shroud?????
The number of vanes on the impeller may be different too but just do not know. You could measure and see if you have the long or short water pump.
Gale, none of those water pumps say they're high flow pumps, just 'heavy duty' based on the bearings and impeller used and that does not mean high flow.
Once he determines whether it's a short or long neck pump he can check Summit Racing for a high flow pump. I thought they stopped using short neck pumps decades ago but I could be wrong.
Personally, I would start with the basics, carb adjustment and timing. Idle mixture on carb should be adjusted using a vacuum gauge, highest vacuum you can get. By ear or RPM can leave you with a lean mixture which will cause it to run hot. Timing, as much as you can get under load without spark knock.
Wouldn't hurt to check the mechanical timing advance as well. Not sure what it should be on that engine but it should ramp up as the rpms go up, anywhere from 15* to 20*. Also make sure vacuum is working properly.
Another thing to check is vacuum leaks, which will cause a lean condition. Check all vacuum lines for cracks. You can use a propane torch, not lit, low volume to check for leaks around carb base and intake gaskets. Shoot the propane around base of carb and along intake to head gaskets. If you hear a change in rpms you have a vacuum leak.
With a new engine, new water pump, etc. the engine should not constantly run 220* whether it has a high flow water pump or not. Get the cruising temp down then if it runs hot pulling a grade you can look at a high flow pump.
