Torinojts
Full Access Member
Yeah I was shocked to see the +.040 in the ambo engine. Also surprised to see my heads cracked. Especially when I didn’t use a drop of coolant, no white smoke, or pushing out of the radiator.
Short answer: yes sleeved and no, I'm going to send the rods through the block to IDI heaven. I did not expect. 040 pistons when I took this one apart.Hacked89 did you get a different block then or have it sleeved?
There is a write up for the upgrade in the tech section. There are 2 different types of the repair kit. One for the small bored boosters, one for the large bore booster
https://www.ebay.com/itm/224070575918
https://www.ebay.com/itm/223816807969
I'm not sure what year the cutoff is for the different bores
I left them how they are, but Wes cut his out larger with a die grinder. The next time I do this, I will enlarge mine. I figure that since I don't tow heavy with this truck and that any coolant flow is better than none, they will be ok as made. I'm certainly not worried enough to pull the engine and replace the head gaskets.Has anyone made the hole bigger in the rubber headgasket insert on the 6.9 heads, or the size they are good enough?
I agree better to not modify it but I don't think it's about speed. Even though the cap keeps the system at a static pressure, there is other pressure in the heads and block that is often greater than that. This prevents hot spots in the heads from locally flashing and when you open those ports up, yes it increases the speed, but it's decreasing the pressure.I did modify those ports, and man did it flow the coolant. I have about a mile an a half driveway from the shop and I could drive down that and 5 miles down the main road before the high idle would shut off on an 80* day with no fan or fan clutch behind the rad. Once it was heat soaked though and fully up to temp I think it may have hurt more than it helped, seemed to move the coolant too quick. I believe the small sized holes are to equalize coolant flow around the cylinders and insure proper heat rejection by slowing it down, but it’s hard to say. I’ve left them alone and been pleased with the cooling performance in other engines.