v8 vibration

67rcks · Feb 6, 2009

I am trying to find out what vibration is just normal with v8 mustangs. I have installed a new camshaft and if running the engine at about 2300 rpm or greater (not driving) I can feel it everywhere. Front bumpers, steering wheel, roof, trunk door. My question is isn't this going to ruin the engine, or it is just normal?

The cam has duration about 280s and cannot idle lower than 1400 rpm. In addition, there are high compression pistons oh well the compression is now around 9:1... The crank has been balanced altogether with front dampener and 50 oz flywheel. No shaking is visible on the engine.

Rapid · Feb 6, 2009

I dont have a balanced engine but I do get a vibration at 2100 that lasts till 2500. My cam is not as hot as yours but it has been there for three different grinds.

D.Hearne · Feb 6, 2009

67rcks said:
I am trying to find out what vibration is just normal with v8 mustangs. I have installed a new camshaft and if running the engine at about 2300 rpm or greater (not driving) I can feel it everywhere. Front bumpers, steering wheel, roof, trunk door. My question is isn't this going to ruin the engine, or it is just normal?

The cam has duration about 280s and cannot idle lower than 1400 rpm. In addition, there are high compression pistons oh well the compression is now around 9:1... The crank has been balanced altogether with front dampener and 50 oz flywheel. No shaking is visible on the engine.

You shouldn't have any vibs at 2300 rpms and above with a 280 duration cam. In fact it should have smoothed out a little above 1000. And it should also idle below 1000. Sounds like you've got a bad vacuum leak. Time to spray carb cleaner around the intake ports to isolate it. 9 to 1 isn't high compression.

BlownFiveLiter · Feb 6, 2009

How's the balancer look? If it's a stock late model 5.0 balancer, check to see if there's any rubber sticking out anywhere around the outer ring. It's pretty common for the 87-95 balancers to go bad and need replacing. I just did it a couple weeks ago on my own. I don't recall off hand what I paid for it, but I picked up a Pioneer SFI balancer from Summitracing for under $200.

67rcks · Feb 7, 2009

D.Hearne said:
You shouldn't have any vibs at 2300 rpms and above with a 280 duration cam. In fact it should have smoothed out a little above 1000. And it should also idle below 1000. Sounds like you've got a bad vacuum leak. Time to spray carb cleaner around the intake ports to isolate it. 9 to 1 isn't high compression.

Carb cleaner? How can you detect the vacuum leak with it?

The front balancer is I guess original and did not have any signs of slipping like cracked rubber or similar

65ShelbyClone · Feb 7, 2009

67rcks said:
Carb cleaner? How can you detect the vacuum leak with it?

The carb cleaner is sucked into the vacuum leak and gets burned, causing the idle to rise momentarily. I have heard of using a propane torch as well, but never tried it.

D.Hearne · Feb 7, 2009

65ShelbyClone said:
The carb cleaner is sucked into the vacuum leak and gets burned, causing the idle to rise momentarily. I have heard of using a propane torch as well, but never tried it.

Exactly !

67rcks · Feb 9, 2009

Could be vacuum leak as heads, block and intake are slightly shaved and another gasket is really needed. I'll try later after fixing the "oil" problem (NEW plastic tube for oil temp gauge melted spraying oil all around the garage)

v8 vibration

67rcks

Member

Rapid

New Member

D.Hearne

New Member

BlownFiveLiter

have car, will race....wait, it doesn't run

67rcks

Member

65ShelbyClone

D.Hearne

New Member

67rcks

Member

Similar threads

v8 vibration

Member

New Member

New Member

have car, will race....wait, it doesn't run

Member

New Member

Member

Similar threads

Privacy & Transparency

Privacy & Transparency