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Motor mount upgrade

Old 09-27-2010, 09:13 PM
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For a H body with more then the average mods, it'* a good idea. There will come a point where the engine will move more then you want. And at that point the mount will be damaged. It'* a easy mod. Took me 3 hours. But keep in mind I had to walk to Menards to buy a drill bit. That killed a half hour.
Old 09-27-2010, 10:36 PM
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dont ya hate that you get into to stuff and realize **** the ssei is tore apart the buick alternator is out of it the 94'* not here and the trucks my only option lol i did that today hehe i needed a washer and out of the 5 million i have i couldnt find one that would work so hadda run up to the hw store in the truck the reason this is bad is my truck hates the city lol oh no i do
Old 09-27-2010, 11:44 PM
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I did that mod a couple times. I used a 3/8" threaded rod of unspecified metal grade, my engine ripped it in half. I used another one, and the same thing happened. Then I went to the Tractor Supply Company, got their highest grade bolt, and that lasted about a day longer before it was ripped into two.

I had heard about people going up to a 1/2" bolt shaft to keep the mount steady, but I simply had two plates welded onto the mount to make it completely solid. It hasn't torn since! Plus, I used the mount style that was used up to 93, without the hydraulic part but just with the rubber chunk, so now I have no clearance issues with my headers.

Dan, please let me know how the bolt is doing in a few months from now. Welding the mount solid may not be everyone'* spoonful of margarine, so I am looking around for slightly more sensible ways to go about keeping the mount whole. Best of luck!
Old 09-27-2010, 11:49 PM
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If I brake that 1/2" bolt I'll add a second bolt where the strut was. 2 grade 8 1/2" bolts should not brake, easily.
Old 09-27-2010, 11:59 PM
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That'* a great idea! Also, are you going to add some bushings to the bolts, or will you just keep them bolted to the metal? I had a bushing in mine.
Old 09-28-2010, 06:23 AM
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If you keep snapping the bolts, I'd look at the angles of things. I did that bolt through method a couple times on other peoples cars before finding that Rockauto has them for $40 with the strut. All are holding well to my knowledge.

I never understood why people were buying threaded rod instead of a bolt.

FWIW there is no bolt through the rubber on the mount I was using, just in the strut area. It'll be out soon and it should still be 100% intact. I had figured the rubber would rip quickly.
Old 09-28-2010, 08:07 AM
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If bolts are breaking then you either have to weak of a bolt. threaded rod is not the right choice. Or the bolt is not straight to the motion.
Old 09-28-2010, 10:14 AM
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1/2" grade 8 bolt for 9 months now without issue.
Old 09-28-2010, 10:45 AM
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Another update on the KR issue. After talking to Bill, again. He mentioned something that got me thinking. So I went back and checked my scan logs. I found the high KR to be in a certain area of the MAF, between about 3500-5000 for the frequency. I then noticed the LTFT was adding a lot of fuel and the AFR seemed a bit low. So a richened up that area a few %. KR dropped a bit. So after another scan I narrowed the frequency to about 3800-4800 and adjusted again. Another scan dropped a bit more. After several more adjustments I was down to 3800-4250. Another scan showed no KR under load in that area.

To help with scanning the cruise area I found driving the car up on to ramps hits that area perfectly. Your at low speed, high load, MAF frequency is right about 4000. Just like driving between 40-50 and going up a hill. Now to drive a few days and see if the problem is corrected.
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