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I went racing today and got in 11 runs. The car ran good 12.8 to 13.2 at around 108 mph. The traction went away after the first hour so did the times. My last run I heard something in the engine compartment but it was still pulling so I stayed in it. After the run it did seem like a thud or something. Open the hood and the shroud is broken at the top. I found a couple of pieces of shroud scattered around the engine compartment. Hmmm. I tried to torque the engine to see if it would lift but the E brake on these cars is pretty bad. I did not race anymore due to I did not wat to see something poking through the hood. On the drive home I tried to see if I could get it to move at all but there was a lot of traffic so I could not really get into it. I'll probably yank the mounts but is there anything else that it could be. There has always been plentl of clearance before.
Sounds like an engine mount to me :yesnod: Don't know of anything else that would let the engine move far enough for the fan to get into the shroud. It didn't happen to be pulling the left front fender higher then usual when you were going down the track when you heard the thud did it? I had one break on a buddy's 65 mustang whne I was test driving it after a carb and intake change, I asked him if it notmally pulled the left front fender that high, he said no, found out later that it broke that mount.
You can be sure the left mount is broken on your car. If you're hearing the fan make any contact at all when you stomp on it, the left (drivers side) mount has let go. The right side mount never breaks, at least I've never seen one let go yet!
If you do lotsa dragging we always used to chain down the left side of the block. Its the side that always tries to lift when you get on it hard. When there's too much movement, thats all lost power. So after you do the mount, you should consider chaining that puppy down a bit. Helps save the mounts too!
11 runs :eek: No wonder something broke...lol. Atco is pretty good for the # of runs you get sometimes. Got 7 runs within 5 hours with my truck that one time.
Anyway about the rad. shroud, I took a nice chunk out of mine as well at the first corvette challenge this year....went and checked the mounts and there werent any problems. turned out the shroud wasnt mounted too well....just something to look for as well.
If indeed it is the mount, Indynut makes a good point about the chain. I have even seen some guys set it using a polished bar with tie-rod ends. Looks a litte better than chains esp if you are into car shows as well.
Engine mount. I recommend Moroso 1/4" thick solid mounts...go here: http://moroso.com/catalog/categorydi...?catcode=28100 and get #62500 which is what I have...actually requires that you bend the mount out a bit...I stradled the mount on a 4x4 and whacked it with a hammer a few times. Or, you can get #62530 which is only 1/8" thick, but has the correct dimensions.
I did check the shroud mounts and they are all tight. If it is broken might go with the solid mounts. I'm not to much into the showing even though I won a trophy today. Don't know why the car was dirty (water restrictions here in Jersey). Does that make me a waxer. I hope not. Haven't waxed it in a year. I'll be under it tomorrow to check the mounts.
I recomend energy suspension moter mounts. Get the black ones that are graphite impregnated. They are good sturdy mounts and dampen vibration well.
The left motor mount will lift if the motor is loaded with trans in drive. The right motor mount will lift if loaded with trans in reverse. This is how you can check them individually. They may both be broken and or either one weak.
Hey Gordon,
Nice times!!!
Are the mounts welded to the frame at any point or is it a bolt-in? Do you need to lift the engine out to replace mounts? Just curious...
:cheers:
Tom
It sounds like the mounts to me as well. I too once discovered a broken left mount by hearing the fan impail itself against the shroud under "above normal" acceleration. It's a relatively easy job, but like others posting here, I would recommend a stronger mount given your driving (racing) habits.
HEY GORDON,SORRY TO HERE YOUR HAVING PROBLEMS. IF YOU NEED THE ENGINE HOIST I STILL HAVE IT GIVE ME A CALL IF I CAN HELP OUT. BRING YOUR CAR OVER IF YOU WANT OR I CAN PUT IT IN MY TRUCK LET ME KNOW
427 Roadster You can replace them by just jacking the motor up a little and remove the mount. They are bolted to the block and a bolt holds the mount to a welded in breacket at the frame. Not a big job. I will replace both if one is bad. I'm sure it was the left one. It happened while I was shifted into 3rd gear and the shroud is damaged on the top right side.
It sounds like the classic Left motor mount failure tome. A friend of mine did that in his 69 Camaro...same thing...fan shroud toast. Get a good "safety" mount. They have interlocking metal pieces that prevent movement in case the rubber/poly fails limiting movement. I have Engery Suspension Poly mounts.
BTW Love the picture in your sig. Your car really launches and it looks great too :yesnod: One of my dream cars is a 1970 LT1 Convertible, but I'll stick to my 1971 ZZ4 for now (until I win the lottery).
John
Gordon,
Do you really want to deal with the added vibration from solid mounts? I used to break motor mounts in my Camaro with the 383 ALL the time. I switched to Energy Suspension polyurethane mounts and have not had a problem since. They're about 100 bucks a set, but well worth the money.
I have driven a car with solid mounts and it was not all that bad. If the polyurethane are just as good I'd like to keep the vibration down as much as possible.
I was also told that the right side never breaks, I was having the same problem with the fan shroud and it stopped when i took out the broken mount on the left side. Now seeing that i bought both mounts from the GM dealer for $54 each list price, I was going to put the right side in this morning. Guess what, that one also cam out in 2 pieces. The ones i took out were GM ones that pulled away from the metal. Easy job, done in 1 hour for both sides
The factory rubber mounts usually fail due to high heat. The Energy Suspensions claim to pe impervious to heat. They're way stronger than factory mounts and just as smooth. Your right mount will break more often if you drag race in reverse. :lol: Many times the broken right mounts go unoticed due to the fact that the engine lifts the left side in forward motion.
I would check your trans mount as well and consider getting the ES graphite mount for there too.