Administrators, why do I get no picture and "www.thedieselpage.com" in white squares? An inquiring mind wants to know.
Administrators, why do I get no picture and "www.thedieselpage.com" in white squares? An inquiring mind wants to know.
Mark Chapman DP member #653;
1983 K2500 6.2 Suburban, 4" lift, 35" tires, ATS turbo, Banks exhaust/intake, pyrometer, tachometer;
1986 K5 6.2 Blazer, 2" lift, 33" tires, Banks intake, pyrometer, tachometer
1963 wife, one owner, average mileage for the age but in excellent shape, a keeper
1992 daughter, low mileage, pretty, limited edition, but requires some money to maintain
1995 son, sports model, very fast & peppy, time will tell on durability and maintenance costs
"Grease is good"
Simple solution. PM or email me with your OS and browser versions (XP, 98, MacOS-X, firefox, Internet Explorer, etc), and the link (address) you use to access the website.Originally Posted by Subzilla
I agree with not bypassing and had first hand experience with another fleet of GM engines - the 53 & 71 series 2 cycles. I worked across the middle east during the oil boom of the late 70's and early 80's and the 2 cycle Detroit Diesels were very common, we had several 4-53, 6V-53 and 8V-71 engines in our fleets.
When cooling became an issue our mechanics started pulling thermostats and rerouting coolant from the back of the heads. Just like what is mentioned here - the heat was not getting carried out of the engine as designed and made the problem worse. Coolant passages are designed to utilize the hardware in a certain way and if bypass was necessary it would have been done at the factory.
350k+ miles of 6.2/6.5 experience
Any chance the origanal post could be saved as a sticky on the 6.2 tech forum or made into an artical for the diesel page? Great work and pictures.
86C 6.2l gmc
"This to shall pass"
"Life is to short for a Tim Horton Line up"
On a related note: The fourth image is of a 6.5 block that had a problem running the hill during our Pull-Off in 2002. You can see that the piston in cylinder #6 was damaged along with the cylinder. What is also visible is that #8 was undamaged.
Whether it was a competitive driver or just too much going on to keep track of, the engine temperature crossed 250 degrees and EGT went above 1500 during that run. Also, one of the other photos used here was of the very same rebuilt shortblock with new ceramic coated 18:1 pistons...
Jim
I'm pretty sure what Grape is doing is pulling water out of the pump, piping it down the outside of the block and bringing it into the block in the center of each bank, probably through a freeze plug hole or other newly machined inlet port. Then, by opening up the transfer passage in the front of each deck surface, he can allow the coolant to flow from the center of each bank forward and rearward, then up through the heads and out at both ends. He's probably added a larger passage to pass coolant to the heads in between the center two cylinders on each side as well. This way he gets nearly parallel flow, rather than the series loop that the factory has. This approach has to be carefully metered to balance all the flows to avoid hot spots. If done properly, it will maintain more even temperature distribution throughout the enigne.
Just guessing.
So why doesn't the head gasket have holes in it to match up these coolant passages? (in blue)
6.2 NA, SM465, Dana 18, Saturn OD, Dana 60's all crammed into a 1970 Series IIa 88" Land Rover
1998 K2500 Burb, relocated PSD, upgraded injectors, cold air intake.
http://www.aloharovers.com
I was reading the article and why would you make the holes in the head gasket so much smaller than the passages in the block and head?
Also wouldn't make the engine run cooler with increased head gasket passages?
Wouldn't you drill them out to match the ports in the block and heads?
1995 Chevy 2500, 6.5L Diesel mostly stock 234,000 miles. Changed the water pump to HO WP, deleted the vacuum pump and added a mechanical wastegate controller made by me with info from others on the forum.
There are a lot of engineering principles involved with coolant flow and heat transfer. The various holes in the head gaskets are sized to allow a prescribed amount of coolant flow. The size of the coolant passages in the head/block are the size they are for at least a couple of different reasons.... 1- Manufacturing ease and core cleanout. 2- To control coolant flow.
This is why the article was written.... Wannabe vendors just can't decide on their own to change coolant flow without some sort of dynamic testing on a fully instrumented engine to measure the effects of any change. The vendor data should also be published so it can be verified.
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