Accetpable temp. range for an 88 SPL?

[wwerdell]

I just finished replacing the thermostats and both gaskets that sit on the heads.

The temperature is running much cooler now but the starboard side is still running about 15 degrees hotter than the other 2 cylinders. At 2,000 rpms for 10 minutes the temp maxed out a 136 on the right and 120 on the left. This is down from 182 on the right (almost instantly) and 146 on the left this morning.

Is this difference/range acceptable or do I have another problem lurking deeper in the engine? I am still afraid to take it out on the water and get stuck.

 

[oldcatamount]

Re: Accetpable temp. range for an 88 SPL?

Water is moving up into the motor from one side, over and around the top, and then down the other side which will give you the variance you have described. I think your motor is fine.

 

[wwerdell]

Re: Accetpable temp. range for an 88 SPL?

Thanks for the reply.

Based on some of the other posts I've found online it seems like an acceptable range is anywhere around 145 and below and it looks like the alarm goes off at 180. Hopefully the rain will stop early enough today for me to take it out on a test run.

 

[ezeke]

Re: Accetpable temp. range for an 88 SPL?

Ther temperature switch closes to sound the alarm at +/- 203 degrees F. and reopens at +/- 170 degrees F.

At 203 degrees it is possible to already have engine damage, but at the least, the cause of the overheat should be fixed before the engine is run again.

A 15 degree difference between banks is not acceptable; you may need to check your water passage deflectors and test your thermostats even if they are new.

 

[ezeke]

Re: Accetpable temp. range for an 88 SPL?

Water is moving up into the motor from one side, over and around the top, and then down the other side which will give you the variance you have described. I think your motor is fine.

This is not correct for this engine. The water moves up the central core under the water cooled rectifier, and then circulates through the water passages evenly. Any diifference is attributable to design and/or obstruction.

 

[wwerdell]

Re: Accetpable temp. range for an 88 SPL?

Are the water deflectors thesame thing as the the water jackets and would it matter if the temperature difference occured while the boat was running with ear muffs? I read a post that said this was a problem while in the driveway but not in the water.

 

[ezeke]

Re: Accetpable temp. range for an 88 SPL?

The water paasage deflectors are pieces of tubing that direct the flow of cooling water around the cylinders.

The cooling water is not under tremendous pressure at any time so that any obstruction will decrease the flow in favor of unrestricted flow. That is usually the cause of uneven temperature, though it may be because of uneven thermostats.

See the pictures.

 

[wwerdell]

Re: Accetpable temp. range for an 88 SPL?

Thanks for the information. The pictures were exremely helpful.

Do those just pull out or is there more to it than that? Based on the diagram you provided it doesn't appear that these are bad. They looked pretty clean and there wasn't really any sifnificant build op on either side of them as far back as I could see.

Most of the buildup I had was around the starboard side thermostat and in the housing on that side. I had assumed that was because it was locked shut whcih it definitely was. Any other areas I need to check that may be clogged or partially clogged?

 

[ezeke]

Re: Accetpable temp. range for an 88 SPL?

Just be sure that the bleed holes in the thermostat valve body are not blocked.

The water intake screen in the lower unit must be in good shape or small particles will reach the thermostat housing and block the system.