Community Forums

Taxman · 05-24-2007, 02:52 AM

What effect will bypassing the heated water jacket under the TBI have on my 1989 454?

Intuitively, a colder intake charge should result in better performance. HST, there is a danger of poor atomization and "puddling" beneath the TBI. Is that why the water jacket is there – to aid atomization and prevent puddling under all driving conditions?

Is the heated water jacket a cold weather requirement? Or is the heat required for normal driving?

I have installed a Banks PowerPac, Gear Vendors, 180 degree thermostat and a MSD 6 ignition (10 degrees advanced). No chip as yet. Engine generally cruises with water temperature at 190 to 210 degrees, depending on outside air temperature and load (hills).

I'm always looking for improved mpg and power.

I took the hoses off because they need replacing due to old age and decrepitude, and after I got them off, the thought occurred to me that I might get a smidgeon better performance with the cooler intake air charge.

The possible downside is the aforementioned poor atomization and/or "puddling." IAE, it will be easy to replace the hoses, if I have to, if the experiment doesn't work.

I was hoping that someone on the forum had experimented with taking the heat out and could get back to me with their results.

Taxman · 05-24-2007, 02:52 AM

What effect will bypassing the heated water jacket under the TBI have on my 1989 454?

Intuitively, a colder intake charge should result in better performance. HST, there is a danger of poor atomization and "puddling" beneath the TBI. Is that why the water jacket is there – to aid atomization and prevent puddling under all driving conditions?

Is the heated water jacket a cold weather requirement? Or is the heat required for normal driving?

I have installed a Banks PowerPac, Gear Vendors, 180 degree thermostat and a MSD 6 ignition (10 degrees advanced). No chip as yet. Engine generally cruises with water temperature at 190 to 210 degrees, depending on outside air temperature and load (hills).

I'm always looking for improved mpg and power.

I took the hoses off because they need replacing due to old age and decrepitude, and after I got them off, the thought occurred to me that I might get a smidgeon better performance with the cooler intake air charge.

The possible downside is the aforementioned poor atomization and/or "puddling." IAE, it will be easy to replace the hoses, if I have to, if the experiment doesn't work.

I was hoping that someone on the forum had experimented with taking the heat out and could get back to me with their results.

Jimary · 05-24-2007, 03:32 PM

I have never tried that, but think it is mostly for winter operation in the northern climates to prevent throttle body iceing.

Gary RVRoamer · 05-24-2007, 06:03 PM

You've put a lot into that TBI engine - have you considered converting it to multiport instead? There are kits available...

Multi Port FI

Taxman · 05-29-2007, 02:43 PM

Gary,

Thanks for your suggestion. Will consider it after our "Great Road Trip II."

For now, I'm going to go with what I've got.

I am, however, going to put a shut off valve in the hot water return line and try it both ways -- hot and cold. Will inform forum of the results.

FRank