safe temp for a Perkins 4108 50hp?????

Hi Friends, I have a Perkins 4108 50hp I just rebuilded one month ago, before the motor runs in 160 at 2000 to 2400 rpm and now 190 to 210. I replace the cilinder head with a old one, the two water pumps, and the termostat, bearings, rings etc. My father westerbeake run at the same temp its safe to use the motor between 190 to 210. Iam afraid that the head have cut in the machine shop or the other thing the gasket are not the same but Iam 98% sure that I checked very nice. Last weekend I drill holes in the term and the motor continue in the same temp. Then I taked out and the temp raise very slowly but finally after an hour goes to 200 to 210. Thats normal, we have warm water here I can continue using the motor without the therm o is necesary for water preasure. I dont no what else do Ideas ????. Or its still safe at 210 please let me Know. Another thing I need the fuel line that left the motor fuel filter and goes directly to the fuel injection pump if some have it Iam interesting in bough it. let me know.

 

210 sounds about right, possibly even a bit cool for a diesel. I would not worry about it.

 

Thanks again Seafarer24 for your fast reply, you think 210 its right that sounds good to me another thing for not be worry. And about the termostat its important to have it or just leave without him.

 

I would leave a thermostat in provided the engine does not run above 220 degrees. Engines are designed to run at a certain temperature. They last longer and perform better that way. The thermostat allows the engine to reach this temperature more quickly. Diesels generally run hotter than petrol engines as they use heat to ignite the fuel instead of spark.

A cold diesel is not a happy diesel.

 

Something is definatly WRONG , sure modern diesels run at higher temps to get by the air polution folks , but this antique should run 180 forever.

Did you flush the block?

Did you loose "ears" (impeller pieces) from a sea or fresh water pump?

Can you pull off the line to the heat exchanger to sse if adaquate cooling water is getting THRU the cooler?

Have you messed with the fuel timing?

IS the prop clean , and the shaft aligned?

Does the engine smoke BLACK while under load?

FAST FRED

 

Fast Fred I agree.What concerns me besides the temp. is that it should not fluctuate to that degree IMO.The system is not working properly and you could get by for a while but it will continue to get hotter and damage will follow.I just bought a crated one (complete rebuild) for 1200 at an equipment auction and stuck on my gear to marinize it.Good to go for another 20 years.It maybe old but I wouldn`t trade it in for some electronic,turbo...

 

Seriously? A 180 degree diesel? I've got gas engines that run hotter than that. Old gas engines, not just the newer ones. And fairly old diesel engines that never ran at less than 200 degrees it seemed.

 

My botton its cmpletely new, the fuel timing I think was correct a placed the pump aligned with the block, the black smoke dont appear anymore, and yes the temp raise when the boat its in gear in 2000 or 2400 rpm is not still in 130 without gas. The only concern is why before was not in 180 or more an now raise to 210 all the water pumps are new. It could be that the rings are still hard???? or just forget the thing that Seafarer toll me . Thanks again

 

I was sure various minerals start to drop out of hot water between 145 F and higher. Raw water cooling should be run around there. Closed cooling side can be higher. However, you will still cause mineral deposits to form in the heat exchanger. No way around +145 F and deposits forming. Yes, you do have to change oil more often on raw water cooling engines to remove water vapor which forms on each cool down. Salts are what destroy raw water cooled exhaust systems. No way around these conditions.---------------------------------------------- As to why the higher Temps? Wrong gasket is blocking SOME of the flow. Wrong cylinder head is blocking. Head is worse than original one. Crud in engine has come loose and raiseing to 200 F. Did not vent all the air pockets out of the cooling system. Small leak from cylinder thru head gasket to cooling water. Lots of things to check out.

 

If you have a 180 thermostat your engine should run aprox. 180.If it opens at this temp the cooler water will decrease the temp. and then close again.This thermostat is not closing and therefore is not working with the rest of the cooling system.The whole unit has to work together.If your thermostat never closes and yours is not you are having a problem(I`m afraid it is just that simple).

 

Hi friends, Seafarer toll me 210 I ask to a mechanic and he toll the 4108 in machines work at 210 to 225 in marine use a little bit less like Seafarer say. But about the termostat is 160 F I try it before do the holes and the temp raise anyway. Its posible to try with a 180 termostat or still use the 160 with the holes. The only thing I dont check was the heat exchanger cumb some toll me that maybe is stock with alges and salt rocks because that piece sit in my house for one year during the overhaul of the motor. Sorry about all that story again but Iam trying to understand all the choices. If anyone around have a 4108 that can toll his current temp. thanks to everybody this forum is great.

 

Take off the heat exchanger and go to a shop that rebuilds radiators . They can flush BOTH sides with an acid , at a low price.

If you wish most can be disassembeled and rodded to clean.

Use a dowel or soft (copper) rod small enough to fit thru the tubing and just keep working at it. CLR sometimes is a help .

You can cut gaskets from gasket material from NAPA if you can't find one.

More than likely THIS IS your problem.

FAST FRED

 

I just finished my sailing season, but my 4108 never went over 180F. It's a fresh water cooled heat exchange system.

Danny

 

I ran mine at 80c, but was told 90c would be ok. another thing I was told, this engine should not work too hard, ie have too big a prop. As far as I remember it should run at 3600rpm wide open with no load, and not less than 2800-3000 under load, wide open. I don't remember it with any degree of certainty though.

 

With all diesels it is safest to have at least a 10% drop between whatever IS observed full throttle RPM and cruise.

This is PARTICULARLY important if the boat is fitted with a "cruising" prop , designed to push the boat at normal cruise at lower RPM's.

Such a prop will ordinarily save fuel and allow the vessel to move at much quieter enfgine speed. At "full" throttle the engine would NOT get to mfg recomended RPM .It would be "overloaded".

Therefore the caution of the MANDITORY 10% reduction from whatever RPM the engine actually does pull.

For most pleasure boats 200 to 300 rpm pull back on diesel and at least 500rpm on gasoline is prudent.

FAST FRED