Rocker Adjustment Big Block Chevy Solid Roller - need help!

[BOSTONCAMARO]

how does a bump switch work? do tell, thanks!

[oj]

A 'bump switch' is generally built into the firewall, in the middle or one on each side, they are used to 'bump' the engine over so you can adjust the valves.
I tend to wire them in front of (electrically speaking) the main power switch so you can bump the motor and not have to worry about somebody turning the ignition switch 'on'.

[Traditions Racing]

Build yourself a bump switch for the tool box as good as a Snap On one very easy. Buy a heavy duty starter push button switch, a few feet of 8 gauge primary wire and some equally heavy duty alligator clips to match the primary wire. A length of primary wire to each of the terminals on the switch and the other end to one of the clips. Shrink wrap the leads on the ends would be wise too. Now you just clip one end to the 12 volts battery lead on the starter solenoid and the other to the S or Switch terminal on the solenoid, hit the button and wallah!!.

M.S.D. and Jeggs both make excellent timing tapes if you insist on doing it that way. Remember timing tapes are like beer, you don't own it, you usually just rent it as the tapes fly off eventually at will just as you leak out the old beer. Speaking of beer.................

TR

[rustednutz]

Now a question for you, How does a cam with a lot of duration or a wide lobe separation angle affect these methods of running the valves?

[BOSTONCAMARO]

that is what I thought......a bump switch was, we have a starter seloid there, we can use that to bump it..and think we do have a bump switch

[Traditions Racing]

Snap-On Remote Starter Switch this is what we use at the track. Part # MT302BR.

If you build your own from my post above with say a universal starter push button from Speedway or Napa, remember one terminal on the back will always be HOT while it is connected and with some finessing you can make a nice insulated cover for the terminals ie large shrink tubing or a small length of heater hose.

I am absolutely with the crowd of when the EX opens adjust the IN, when the IN starts to close adjust the EX. It is easier than it sounds and absolutely correct.

Keep in mind, if you have not checked and corrected the TDC mark if your running a stock type damper, how accurate will be the timing tape for 90/180/270 degree marks as well.

Best of luck, TR

[BOSTONCAMARO]

it is a quality aftermarket balancer but not fully degreed

thanks, i am going to look into that bump switch

[Traditions Racing]

Originally Posted by BOSTONCAMARO

it is a quality aftermarket balancer but not fully degreed

thanks, i am going to look into that bump switch

BOSTON, yes I was assuming you had a aftermarket balancer, but and here is the clincher, is the POINTER adjustable and verified it coincides with true TDC? That is the key my friend. You can run the best balancer in the world, but you must have the TDC pointer verified with the mark on the damper. If your pointer is off, then the true TDC is off, and then if you put a timing tape on or even a balancer with 90 degree segements marks out, they will all be off accordingly, make sense?

You dont need a fancer high dollar adjustable pointer either especially on a Chevrolet. A $2.99 Mr. Gasket pointer and a pair of tin snips is all you need. Once you establish TRUE TDC, trim the el-cheapo pointer with the tin snips so that you have a point that faces to the front of the engine, that coincides with the TDC mark on the damper. Remember you no longer need the window and the other marks on the tab, only a point that lines up with true TDC. Shoot your timing now with the point and the amount of TOTAL timing you will run and read it directly off the damper. Say you want 36 degrees TOTAL all in at 3000, rev her up to just past 3000 RPM's, shoot the timing light at the 36 degrees and the tip of the new pointer you trimmed out, or turn the distributor as needed. Hope that helps.

TR

[BOSTONCAMARO]

yes it is....adjustable and confirmed...just we have been away from this awhile, we should be all set now, thank you for the help! we should have it running later this week, my parents are in Maine for a few days and I am tied up with my son (2 year old)

[BOSTONCAMARO]

adjusted tonight. did it cylinder by cylinder in 90 degree increments following firing order all looks good! thanks again..took some time. but was right way

[BOSTONCAMARO]

Got the car running tonight!!! at first it had a little clickity clackity, one adjuster either backed off or we didnt have it tight enough, set it up on number 1 again, set that one exhaust valve car started and ran like a monster! also through the belt...still needed to alight stuff a bit straighter, ended up eating the flex fan...got it all apart now and new parts on way tomorrow....

anyway the car runs great, ran 11 degrees of initial timing (have 7AL and timing computer with dial) and still need to tune carb, but man it sounds sick and VERY healthy through the Corvette sidepipes....

Thanks again to all those who posted, we should have the car on the road soon...now onto the brakes..

[BOSTONCAMARO]

my dad, presetting idle screw before its second start as it was backed down too much...an off the shelf 850 that will eventually see some jets etc, but for now just want to get it on the road.