Loosing coolant on 454 fwc

I have 1984 454 fwc engines on

I have 1984 454 fwc engines on my starboard engine I loose 1 gallon of coolant every 50 hours of running time. Engine does not overheat and runs fine didn’t see any traces of coolant in oil. Can it be the head or I have to look for a leak.
Thank you
One more question good place to order a pair of 600cfm carbs and which brand?.

You might have a gasket leak i

You might have a gasket leak in the exhaust system that's letting some slip by. I'd just keep an eye on it and add gylcol.

Got my Edelbrocks 1409 carbs from amazon.com (believe it or not). Had the best prices. Replaced my old Carter AFBs--much better and burn less gas (1/2 GPH improvement per engine).

Note: Edelbrock sells an adapter to mount them where QuadraJets go.


Jeff

"Denis, I'm not that famil

"Denis, I'm not that familiar with a closed cooling circuit on a boat. Just out of curiosity, what cools the exhaust in a closed circuit? And I also take it that you don't have water exiting through the exhaust in that environment either. Have you ever looked at the radiator cap while the engine is warm? A lot of times in an auto the caps get old and allow steam to escape while hot and over time that equates to lost coolant.


Jeff, I take it your not a huge Quadrajet fan......LOL"

"I had a very similar issue an

"I had a very similar issue and actually ended up getting water in the oil.

From what I understand, it could be several issues.

Heat Exchangers - I ended up having them cleaned out and pressure tested.

Next it could be the Exhaust Manifold. (I am going to replace mine. let you know what i find.

I did have my heads rebuilt. But the mechanic said my issue is not with the heads.

hope my issues help you."

Thank you for the info Jeff wi

Thank you for the info Jeff will 1409 model carbs work on 454 with the adapter and do you what else I need to make a change.
Thanks Denis.

"I assume your motors have Q-j

"I assume your motors have Q-jets? If so, they'll bolt right up with the adapter.

You need to do three things:

1. Drill the base of the carb for a PCV fitting and hose. This can be done front or rear of the carb. (Why Edelbrock doesn't do this is a mystery to me!) I have photos (thanks to Fred) of what this looks like. Let me know.

2. Adapt the choke (assuming yours is NOT electric). This requires a 12 volt in 'Key ON' source.

3. Modify (if you're a cheapskate like me) your flame arrestors to fit the Edelbrocks. I know the ones for Carter AFBs are too small in diameter; not certainabout Q-jets. (Anyone out there have the answer?)

The throttle linkage is about right, and they work great!

Jeff"

"on the coolant leak, it could

"on the coolant leak, it could be any of a dozen items. The easy ones to check are all the clamps and fittings where the hose connections are. Also, check the pressure cap. Sometimes a strategically placed paper towel can catch the drip your eyes can't. It that doesn't find it, you'll have to get a pressure tester.

Keep an constant check on the oil level to make sure it isn't rising - also look for any 'milky' tint to the oil - both signs that the coolant is going into the oil pan.

On the carb mod, you can omit step one in Jeff's directions if you engine is still factory equipped, Crusader (the thermo-Electron) didn't use PCV valves. It won't hurt anything to add it but you'll have to get the valve, grommets, hoses, etc.

On the flame arrestor, the edelbrock has a 5 1/8" diameter air horn flange. Most factory equipped Q-jet flame arrestors have a diameter just over 5" so the mod in Jeff's step 3 is the economical option. If you go this route, make sure the arrestor sits flat on the flange of the carb, any gaps may provide an escape path for a potential backfire. Also, DO NOT use the "air cleaner" gasket under the flame arrestor."