I know that most people say that ARPs don't need to be retorqued, but as was previously addressed in a prior thread, Heidi's car was behaving poorly in the 95 + heat around here.
In our quest for betterness, we cleaned the radiator, replaced the T-stat and T-stat housing, and it was runing great.
Except at speads under 20, where it would still warm up a little.
Well, I knew that the motor had seem some detonation when Heidi rolled new bearings in and #4 was pretty beat up. We plastiguaged the bottom end, and all was well, so in went new toyota bearings and all was well until the heat showed up.
So I finally caved and agreed that since we ran a Titan 2 mm HG on a factory finish deck, maybe the headgasket was blown, and it was just giving us minor grief as a warning to fix it. A few days later, the overflow bottle started bubbling after we shut the car off. and we began to lose a small omount of coolant out the bottle. But down inside I had a thought that "maybe" the head had lifted with the detonation, and when the motor was not under load, perhaps the head wasn't being clamped tighly enough to keep all of the combustion gases out of the coolant jacket. When the motor was boosted, I figured maybe the higher EGTs expanded the head, and increased the clamping pressure on the gasket enough to subdue the leak, and this is why the car ran so great under load.
This was a big maybe, but I thought what the hell. Maybe a retorque will fix it.
Well, I pulled each nut back 90 degrees and then, with the torque wrench set to 90ft-lbs, I pulled them tight one at a time, in the TSRM tightening sequence. Much to my pleasure, the studs around cyls 3 and 4 turned 90 degrees to 180 degrees further than my original 90 degree loosening. The others had backed out moderately, except the 4 corners, which were still right on the money.
So I ask myself, why did 3 and 4 detonate back in the day instead of 5 and 6 like we usually see? 5 and 6 run substantially hotter than the other 4 cyls, since they are the furthest from the radiator, and have an egr port that rubs exhaust heat all around the back of number 6.
I can assume that a good running engine and cooling system would have helped to equalize #s 5 and 6 with the other cyls, but why 3 and 4? I think that maybe the stock intake manifold might have something to do with it. Being that the throttle body is right in line with 3 and 4, perhaps they get just enough more air to put them over the edge when running the other cyls on the edge. I cal the edge 19 psi on pump gas, tuned. The motor doesn't detonate normally, but maybe on a hot day, and a 21 si spike, #s 3 and 4 saw just a little biit more air than the other four, and consequently, hurt my bearing, and lifted the head.
Am I crazy?
-Jake
P.S It runs perfect now.
In our quest for betterness, we cleaned the radiator, replaced the T-stat and T-stat housing, and it was runing great.
Except at speads under 20, where it would still warm up a little.
Well, I knew that the motor had seem some detonation when Heidi rolled new bearings in and #4 was pretty beat up. We plastiguaged the bottom end, and all was well, so in went new toyota bearings and all was well until the heat showed up.
So I finally caved and agreed that since we ran a Titan 2 mm HG on a factory finish deck, maybe the headgasket was blown, and it was just giving us minor grief as a warning to fix it. A few days later, the overflow bottle started bubbling after we shut the car off. and we began to lose a small omount of coolant out the bottle. But down inside I had a thought that "maybe" the head had lifted with the detonation, and when the motor was not under load, perhaps the head wasn't being clamped tighly enough to keep all of the combustion gases out of the coolant jacket. When the motor was boosted, I figured maybe the higher EGTs expanded the head, and increased the clamping pressure on the gasket enough to subdue the leak, and this is why the car ran so great under load.
This was a big maybe, but I thought what the hell. Maybe a retorque will fix it.
Well, I pulled each nut back 90 degrees and then, with the torque wrench set to 90ft-lbs, I pulled them tight one at a time, in the TSRM tightening sequence. Much to my pleasure, the studs around cyls 3 and 4 turned 90 degrees to 180 degrees further than my original 90 degree loosening. The others had backed out moderately, except the 4 corners, which were still right on the money.
So I ask myself, why did 3 and 4 detonate back in the day instead of 5 and 6 like we usually see? 5 and 6 run substantially hotter than the other 4 cyls, since they are the furthest from the radiator, and have an egr port that rubs exhaust heat all around the back of number 6.
I can assume that a good running engine and cooling system would have helped to equalize #s 5 and 6 with the other cyls, but why 3 and 4? I think that maybe the stock intake manifold might have something to do with it. Being that the throttle body is right in line with 3 and 4, perhaps they get just enough more air to put them over the edge when running the other cyls on the edge. I cal the edge 19 psi on pump gas, tuned. The motor doesn't detonate normally, but maybe on a hot day, and a 21 si spike, #s 3 and 4 saw just a little biit more air than the other four, and consequently, hurt my bearing, and lifted the head.
Am I crazy?
-Jake
P.S It runs perfect now.