Kerebrus

iTrader: (30)

Do polyeurthane motor mounts reduce engine shake? I heard they do somewhat but cause more vibration or something of the sort? On idle my engine shakes pretty good ( ), normally I thought that's just when it's cold but it seems to be pretty consistent.

djessence

Dont they provide a harder mount so the engine doesnt torque as much, but i would imagine you feel every shake easier. Pretty sure thats why people dont recommend aluminum mounts with a bridgeport because it shakes rediculous amounts and you feel everything.....

Did this start happening all of a sudden? Is idle consistent or does it lope at all?

Kerebrus

iTrader: (30)

It's pretty much been like this since I got the car but I guess maybe more then before. The idle seems to be steady. The car isn't ported, just has a weber48 dcoe on it. The engine "torque" if that's what you call it causes a good shake causing the whole car to kinda of shake, especially the tranny with it. Maybe I should get a quick vid.

trochoid

iTrader: (6)

Do a compression test. Abnormal shaking is often an indication of weak compression on one or more rotor faces. If compression is good, then check the ignition system.

My car rocks from the 1/2 bp, even with the stock rubber mounts.

Kerebrus

iTrader: (30)

Here..

http://www.youtube.com/watch?v=YLaOV_kWKkA

trochoid

iTrader: (6)

I was expecting much more shaking, yours is fairly typical. Even with a perfect tune, you may not get all of the vibration out. You may wish to check your rubber mounts, they could be failing, (splitting), causing the vibration to show more. Stock mounts will dampen the vibration the best, polys will transfer more of it to the chassis. Old dried out rubber mounts tend to be nearly as stiff as fresh poly mounts.

Racing Beat makes an engine torque brace, part # 14030 that will cut down on the vibration. I doubt if you really need the brace, it's designed for high hp engines to prevent motor mounts from tearing apart. It's an interesting part, one of these days I'll get the one I have installed on the widebody.

Kentetsu

Possible causes that I can think of off the top of my head:

1. Bad apex seal. Or, possibly carbon buildup which keeps the apex seals from moving freely. Try a can of Seafoam through the gas tank.

2. Vacuum leak.

3. Poor idle mixture.

4. Bad transmission mount.

5. Timing off.

6. Worn cap/rotor or dirty spark plugs.

7. Faulty spark plug wires.



.

Jeezus

iTrader: (4)

My bet is that your idle is too rich.

Kerebrus

iTrader: (30)

My car is as rich as Bill Gates. So I guess thats why? I bought polyeurthane motor mounts.. those should help correct?

Jeezus

iTrader: (4)

Those poly mounts will only make you feel the "bounce" better. IE as in every miss it makes, the engine will make sure you feel it too.

Kerebrus

iTrader: (30)

Oh.. nvm then :P
It doesnt look like too bad shaking but you can definitely feel it in the car..

trochoid

iTrader: (6)

Work tuning then. Cap, rotor, plugs, wires and timing. Kentetsu has a good point about a partially sticking seal. that could throw off the compression on 1 or 2 rotor faces. do a compression test, then a Seafoam treatment, then run the compression test again and look for any changes. You might want to do the comp test and Seafoam before spending the cash on a full tuneup. It probably wouldn't hurt to lean out the fuel mix either. The more the plugs build up carbon, the less effective the spark is. Consider upgrading the ignition to DLDFIS.

If your stock rubber mounts are hard and beginning to split, they may show more vibration than sound fresh ones would. If you have the polys, go ahead and install them.

NCross

iTrader: (18)

Just try to adjust the air/fuel mixture screws.

680RWHP12A

your carb just needs some adjustments. no big deal. hit up wackyracer, he might be able to help you

Kerebrus

iTrader: (30)

Haha! Right