All Small Six Freeze Plug Popped Out

[Cesarvi17]

Hey guys, have a pretty decked out 200. CI aluminum head port and polished, Roller Rockers, 1JZ rods in it, etc. I believe cam has LSA 113 238/242 with lift .578/.582. Have a T5 off a Foxbody with a 4 cylinder motor. Rear diff is 3.55 Posi. It revs pretty high fine for a 200, but I was driving it the other week and a freezer plug popped out. 3rd gear around 70mph and 3-4k rpms. Anyone know why freezer plug popped out?

 

[aussie7mains]

Torsional vibration will do it, this is why screw in plugs are common on high rpm jobs. However your engine should not have these problems, I would suggest that by using the 1jz rods you have changed the balance factor (the ratio or rod weight to crank counterweight) and this can cause a change in vibration. First gear in the 4 cylinder box with a 3.55 axle must be very low in 1st gear! V8 box is best IMO. Thats also a lot of lift on the cam, id would be making sure your not getting any problems there. The 240 degrees @ 0.050 must make it idle rough and be a bit flat at low RPM, thats a lot of cam for a streeter.

 

[drag-200stang]

I do not believe it is the rods. I have ran much different than stock, weight matched rods with no issues. I think that they simply did not hold in tight. Parts are not well made now days. They should be made so that the outer edge, when set is past the chamfer of the hole so that the edge digs into the straight part of the hole, and not out of a soft material.
Try a stronger sealer.
I also think that the V8 box would be better for our six's.

 

[Cesarvi17]

I would’ve never thought it was the rods either. I’ve known a handful of people who have done this mod before and never had the issue. So far the transmission/motor combo is running fine overall. I did notice however, if I’m going cruising speed on 4th gear with 2-3rpms on highway and shift to 5th, the rpms drop to 1.5 rpms with no room for acceleration. The car stays on and moving but when I give it gas, the car won’t pick up on speed. The guy I bought the motor from recommended to keep the gear ratio of the axle low (he said the motor really picks up power around 3.5-5.5 rpms). However, should I increase the gear ratio? I originally did want to put 3.8-4.11 in the back. The cam is pretty heavy for street use because of the rough idle, but it doesn’t bother me.

Just found out the gears for the transmission: REV: 2.76 1st: 2.95 2nd: 1.94 3rd: 1.34 4th: 1:00 5th: .063

 

[Cesarvi17]

Actually is a good time to bring this up, but I don’t know how much complete timing I need to run this set up either. It needed minimum 32 degrees total to start. I pushed it up to I believe 34-36 degrees and it ran better (less shaky) and faster. I still feel there’s more room to increase it though but I don’t know if that would be a good idea.

 

[frozenrabbit]

Probably just heat and pressure, repop freeze plug could have easily been at the bottom or lower than 'acceptable' dimensions.

 

[powerband]

of course excessive coolant pressure / compression leak into coolant could blow something out but think the radiator or hoses would be pretty obviously involved. I'd go with replacing it after I looked at circulating coolant at above idle ...
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I did blow small hole thru a rusty small freeze plug in the cyl head of my '63 wagon cleaning it up with a big power washer when I first got it. I smooshed some JB"s weld into the rusted frz plug temporarily which held for a few years, actually sold off the engine with the JB's still intact!.
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