jgcable

I figured I would start a new thread on this to hopefully help a fairly common problem. My car is a 77 with a stock L48 in it. Bought the tall black Edelbrock valve covers. This meant I need to get a longer belt for my alternator. I am using the factory stock alternator mounting brackets. Anyway.. I get a belt that is .5" longer and it fits perfect BUT.. there is a problem. The belt hits the power steering pump. The reason for this is as you pivot the alternator far enough away from the tall valve cover it moves in an arc and when it gets to about 2 inches from the end of the slot in the long curved bracket is positions the alternator pulley (and belt) at an angle so that it rubs against the power steering pump. I could see the fix possibly being 2 things.... get normal sized valve covers (when I put my stock ones back on the belt doesn't rub because the alternator can be much closer to the motor and the angle is greater)... or.... possibly (and I haven't figured this out yet) but... if it lines up.. get a 2 groove pulley for my alternator and use the outside pulley and then use the 2nd groove of my crank pulley instead of the 1st groove.

jgcable

This also brings up another potential problem that I have read a few threads on this forum about. If I am able to get a 2 groove alternator pulley AND it happens to line up with the second groove on my water pump and crank pulleys will I end up with a wobbly alternator problem due to the fact that the alternator will be all the way at the end of the long curved bracket? I read a few threads where guys mentioned that moving the alternator out to the end of its travel on that long curved bracket caused it to be unstable enough to wobble. The more I think about it.. I should just ditch my new tall valve covers and get a set of normal height and just use stock belts.

gkull

Some of us here on the forum don't have a choice because tall valve covers are required.

jgcable

I understand that completely but from what I see.. .most of the people that have tall valve covers have them on motors that aren't using the stock alternator mounting brackets. Most of them are using March or some kind of billet serpentine system or aftermarket system which moves the alternator forward towards the front of the motor away from the valve covers so that it can still be close to the motor. When using the stock alternator brackets the alternator is set in about an inch from the edge of the valve covers so if you are using tall ones you have to swing it out almost the entire length of that long curved bracket. It doesn't even look good swung out that far. Almost looks wrong to me.

toobroketoretire

When I installed my new full roller rocker arms on my big block '71 early last summer I ran into the same problem; my valve covers needing to be about 3/8" taller to allow for the taller adjustment nut of the new rocker arms.

I solved the problem by cutting the hex nuts off the tall adjustment nuts then filed 5/32" wide slots into them so I could turn them with a wide screwdriver or narrow putty knife. With the adjustment nuts shortened by about 1/2" my stock valve covers went on with no interference from the shorter nuts.

gkull

I don't have a stock vette in front of me to compare. But I use the stock PS mounts and alternator mounts.


Can you post a picture of how the belt rubs?

jkippin

Wow that would be a real b*tch trying to put a stud girdle on. Good thing you don't have an real aggressive cam that you would need to run one to minimize stud flex.
What an awesome idea I totally admire your keen skills on every level

jgcable

the belt rubs directly on the front of the ps pump. If i move the alternator closer to the motor by removing the tall valve cover the belt angle increases and it no longer rubs.

gkull

Notice how i spaced the alternator mounts out with thick washers?

105 amp single wire alternator



closeup of spacers



Belt to pump clearance






Spare 7500 rpm Rev limited Solid roller motor

jgcable

Thanks for the pics. Looks like you have a 2 groove pulley on your crank and water pump. I have a stock 3 groove. It looks like you are using the 1st groove only. I wouldn't be able to shim my alternator brackets and still use the first groove because it wouldn't align properly considering I am already using it unshimmed. I would have to switch to the second groove. My power steering belt is the 3rd groove. Wouldn't it be easier just to get a 2 groove pulley for the alternator instead of shimming the alternator brackets? Also... did you use the stock curved alternator bracket and if so.. is your alternator almost at the end of it and if so.. do you experience any vibration or wobbling?

gkull

That is a 3 grove aluminum slightly smaller diameter damper pully. My damper is a 6.25 inch ATI.

So water pump and alternator are 1st groove. AC used to be on the middle and power steering on the 3rd

That's kind of how it has been for the last 20 years

GUSTO14

jg, unless you really need the tall covers, I would just get a set of the L-82 aluminum valve covers and everything will fit as it left the factory. I actually installed a set on my '77 L-48 I bought new way back then, when the tin covers started leaking oil all over my brand new engine!

I now have a '73 and am running roller rockers under stock L-82 covers. I've never had any clearance issues with them. I did switch to a set of "thick" cork gaskets for some added insurance a few years back.

Good luck... GUSTO

gkull

Bad advice to run cheap cork when so many other good products are out there.

Get the thick FelPro blue with steel inserts Reusable thick and not crushing. You can use them over and over


I'm also big on totally studded everything on a motor. Stud the heads for the valve covers. locktight them in and you never have to worry about stripping the threads

As to L-82 covers .............. My 79 L-82 was good until I went with a higher lift cam and 1.6 roller rockers. I had to break off the the splash tabs and use the thicker Felpro blue

jgcable

I decided I am going to ditch my tall valve covers and get stock height. I tried the shimming the alternator bracket thing but I need to shim it out too far to catch the second groove of the crank and water pump pulley. It doesn't look stable.
I am going to put my valve covers up in the classifieds. They are brand new and only test fitted on my engine. I like the way they look but its so much easier to go with stock height and use stock belts.

Mako72

I went to the tall valve covers on my smallblock '72 and had the same problem.
I solved my clearance issue by buying a slightly smaller belt which hit the sweet spot of just clearing the PS pump belt shield and having the alternator just clearing the valve cover. You may have to experiment. Also I don't know how tall your VC's are compared to my GM VC's.
I'm running all stock brackets/pulleys/alt/etc on my a/c smallblock.
Here's a pic I cropped as I am too lazy to walk out to the other garage where the vette is presently hibernating, but it shows the alt/VC clearance I have. Belt to shield and alt to VC is close but it works.
As a matter of fact, I have to loosen the alt and swing it out to pull the VC.

jgcable

That won't work for me. I had the tall valve covers installed and the stock belt was too short to reach the alternator pulley. That's with the alternator just about touching the valve cover. I had to get a slightly longer belt. The problem is if I move the alternator away from the valve cover (no more than an inch) and I install the new belt it rubs against the power steering pump because the angle the belt is in is not sharp enough. I am thinking that possibly there are different degrees of "tall" when it comes to valve covers. Mine are the Edelbrock Signature series. Model 4643. I think they may be taller than most.

Mako72

Would it be possible to go to a slightly longer PS belt so that the PS shield
moves away from the alt belt enough?
Sorry, I don't have my vette closeby to look.

MotorHead

Don't give up yet. Yes things are tight but if you like the new valve covers there is always a way. I just used one washer on each of the pulley brackets to move it just a hair away from the power steering pump.

For the valve cover I got a larger belt and hung the alternator out a bit more coming to the near the end of the top bracket. It was wobbly when I ran it so I put another top bracket on and it is now real solid and I can remove my valve covers but they aren't exactly real high, somewhere in the middle of stock and high valve covers.

jgcable

No, a long enough belt moves the alternator away from the motor too much and decreases the angle of the alternator belt which causes it to hit the power steering pump housing.

jgcable

When my alternator is close to the end of the travel of the curved bracket like yours is the belt hits the power steering pump because of the new decreased angle of the belt. In order for my alternator belt not to hit the power steering pump my alternator needs to be about an inch away from a stock valve cover height. My new tall valve covers are probably at least 2" taller than stock