My camshaft is robbing me !

[gbodyera]

Im having problems with my power accesories from my cam. I have a Comp Cams 279THF7 cam. It has a .479/.465 lift and adv duration is 279/297 and @.050 duration is 227/241..

It runs nice and strong at idle in park. As soon as I put it in gear its real choppy and the rpms drop a couple hundred. My vac is reading anywhere from 10.5-12 pounds of vac at idle. It doesnt really change in gear.
-I have checked everywhere for vac leaks with carb spray and found none.
-Tried timing from 6 to 16 initial and 36 all in. Im now at about 16 initial and its the best so far.
-Checked all lines & hoses and no problems.
-Carb is adjusted all around.
I also noticed with my power steering, when I turn the wheel some the idle drops a little.

I read around some and I think my cam is the culprit and is robbing me. Would a vacuum reservoir canister help me out or am I basically screwed?

T.I.A.

 

[MrHernandez]

think i would say yes to the canister, thats the reason i went with a 272 cam cuz i was afraid of having that problem

 

[Bonnewagon]

Absolutely. Get the canister, it works great.

 

[DRIVEN]

Does your torque converter match your cam?

 

[gbodyera]

DRIVEN on Fri Apr 16, 2010 6:44 pm
Does your torque converter match your cam?

Yup. They say its fine with the convertor I have. What about my carb, if its too big or the power valve is too big, would it cause this?

I know last year before I added these new things to my engine, I slapped on a Holley and in gear it shut right off. I took the Holley off and put an Edelbrock on and worked great..

 

[79loserbluebu]

Make sure your valves are adjusted right and you don't have anything causing a misfire like a plug wire boot popped off or anything. Naturally with a engine driven p/s pump your RPM's will fluctuate a little bit when turning the wheels though.

I agree on everyone suggesting the vacuum cannister. It helps a ton. The 280H we had in the car needed one because the engine would die while braking in gear.

What Holley did you try putting on? I think rule of thumb for alot of Holleys is 2-1/2 turns of the screw. Also if it had clear lenses in the float bowls it's alot easier to set the float level instead of pouring gas all over a hot engine.

 

[patmckinneyracing]

I've had a couple of guys go with the Thumper series and they all had the same issues dealing with vacuum. Start with a vacuum canister, which are pretty cheap, and go from there.

 

[gbodyera]

Make sure your valves are adjusted right and you don't have anything causing a misfire like a plug wire boot popped off or anything. Naturally with a engine driven p/s pump your RPM's will fluctuate a little bit when turning the wheels though.

I agree on everyone suggesting the vacuum cannister. It helps a ton. The 280H we had in the car needed one because the engine would die while braking in gear.

What Holley did you try putting on? I think rule of thumb for alot of Holleys is 2-1/2 turns of the screw. Also if it had clear lenses in the float bowls it's alot easier to set the float level instead of pouring gas all over a hot engine.

The valves were adjusted to my best knowledge. I am going to adjust them while the engine is running when I get a chance.

I had a Holley 3310-750 on there. I feel more comfortable with Edelbrock. Im going to go with a 600.

The power steering drops the rpms and if I keep turning the wheel it will eventually stall the engine. I believe its all due to the cam and its shaky idle. It wont do it if the idle is up higher. If I idle the engine higher the vac goes up. I ordered a vac canister from Jegs, it should be arriving tomorrow.

 

[anakputa]

The initial adjustment is to get the engine started, the get some old valve covers and cut a whole out of the center and adjust the valves whites its running. Some cams like when the back off the valve rocker nut until you hear the start clicking then tighten it up til stops, then depending on the cam some run better right after stops clattering/clicking and other run better after it s stops clattering/clicking and turning the another 3/4 of a turn. The vacuum should come up a few more inches and stay steady.
A Vacuum Booster/Can?Reservoir will help for the brake power booster and the HVAC Controls. Let us know how it runs after you adjust the valves..Don't let the oil get on the headers, its a pain in the *ss to clean and could catch fire..If you already know how to adjust valves....I used to work on a Manufacturer Techline/Hotline..

 

[79loserbluebu]

Fair enough everyone has preferences when it comes to carb's.

I would say just adjust the valves and see where you end up. Are they stock rockers? Roller tips? Full rollers? I've heard of the rollers wanting to back off usually they send you something to stop that like locking studs or lock washers but never really have seen a stock rocker nut back off. I've experienced a cylinders lifters collapse and it basically did exactly what you are describing. Have you noticed a loss of power? While turning the engine would stall on mine and it'd run like garbage. Also the RPM's would be lower then normal at both start up and operating temp. I'd adjust the valves and then check in a couple days just to make sure they haven't backed off or indicate a collapsed lifter. If you had carb troubles it may of leaked gas down the runners and started destroying everything but that may not of happened to you like it did to me.

Hope you get this fixed!