This weekend I replaced the pistons and cylinder head on my 943 with the 3204 , s/n 03Y01878. We ran it today for 3 hours and took a heat gun to check temps on the head and radiator. The top tank was 175 the bottom was 148. The head was 150 all the way around. Temps on the exhaust were 500 per hole. I was told my radiator needs to be rod out or cleaned. It is running well. One thing the rpms seems a little low as well , by sound , it sounds like 1800 or so. I can get a photo meter to check this , but what should it run and what should the high idle be?
Those temperatures sound fine to me. What's your temperature gauge in the cab reading? The high idle should be 2550 +- 60 RPM.
Cmark , its not equipped with a gauge in the cab. It has the wiring or what I think is the wiring for the factory gauge. I would be shocked if its turning over 2000 rpm. I will be adding a temp gauge this week even if its generic one till I can figure out the other one. Thanks sir.
Seems good to me. The last two jobs my 953a was getting close to 210*s on hoter days. I would try to keep it closer to 190 by letting it cool. My had a hole in the manifold elbow about the size of a quarter and the radiator was full of dirt. After a 3hr pressure washing and a new elbow Temps stay at 185 maybe 190 if it has been ran really hard. 20* difference. This is based on the factory gauge.
Checked my high idle. Bought a photo meter off amazon for 16$. Its turning 2550 on the money. I am wondering if the governor is working properly. It never chucks any black smoke what so ever.
At 27 degrees between top and bottom radiator tank you have restricted flow. Threshold is about 15 degrees F. High temp should not exceed about 110 degrees F. over ambient temp. if everything is rite.
I'm with OM. A conventional radiator like that one should drop somewhere around 15-18 DegF between inlet and outlet. A number much more than that range should be regarded as a bit suspicious, most likely due to low flow.
Restricted flow possible, but the restriction could be the thermostat not open all the way because it is not very hot out and/or not working that hard. 175 top tank tells me it is not really getting hot, would expect it to be over 185.
Get the engine up to 210 and see what the temps on the radiator are, then you'll know if you have a problem. What did the inside of the block and old head look like? IF you have a scale problem, you could try backflushing the radiator.
The block and old head had very little scale in them. I asked about this to try and head off any heating problems on this fresh build. I am trying to locate the parts to put the factory style gauge in the cab so I can keep a better eye on it. Before with just the monitor light I think the temps would run up higher than they should for a while then the light would finally come on. Now the weather is cooling off so its not showing any signs of heating at all.
Silly question. Does it actually have a thermostat in it..?
Nige , first off glad to see you back around. And to answer your question , I can't say for sure. I thought about ordering a t stat and trying to flush the radiator while its drained. I am having vapor out of the oil fill tube. It goes away in the air , don't know if its moisture from where we had the engine apart. Before the vapor lingered.
If you don't know if it has a stat or not the first thing I would suggest is to find out, maybe also flush with clean water while you have everything drained. Then refill with new coolant and see how it goes from there.