I finally started putting my motor together after about two years of trying to get to it while finishing college again, having two more children, and starting a new career. I need some advice on setting the cam up. I have the nice JP timing chain set from the Cox Bros and have a custom cam similar to Slantzilla. Here are the specs on the card from Comp Cams.

                                        INTAKE       EXHAUST
Valve Adjustment                          .012            .012
Gross Valve Lift                          .502            .511

Duration at .015 tappet lift               273             279
Valve timing at .050                OPEN                   CLOSE
                      INT:     13    BTDC      43      ABDC
                      EXH:     52    BBOC      10      ATDC

These specs are for cam installed at 105 intake center line
                                         INTAKE       EXHAUST
Duration at .050                           236          242
Lobe Lift                                .3350        .3410
Lobe Separation                          108.0
-------------------------------------------------------------------

I placed the timing set on by positioning the crank the cam straight up and then lining up the dot on the large cam sprocket to the 0 setting on the crank sprocket. I was thinking that this setting should be pretty close to where I wanted it to be, but I was looking back at past posts and discovered that many people found the "lining the dot" method to give a retarded setting. Where do I want to position the timing settings? I would appreciate any help on this.

If the cam and timing set are machined properly, that should give you a "straight up" installation. That would mean the cam would have to be machined to give 105 installed CL.

The best way is to get a degree wheel and dial indicator on an adjustable base and degree it in, but you'll likely be fine just installing it as you say since those are high quality parts. I assume the crank is in the TDC position?

Lou

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Home of Slant6-powered fun machines since 1988

I did install it with the crank at TDC. I'll be using the balancer that I got from you last year Lou. I thought the quality of the timing set would give me a true reading, but I wanted to make sure. Hopefully this motor will run pretty strong. I just wish I cut the deck some more... like another .100. There sure was a plenty of piston to valve clearance even after cutting the head .180 & .080. (Angle mill)



Thanks, Joe

You should at least be in the 9.5-10:1 range with that head cut, which is about perfect for that cam on pump premium if the timing curve is set up right. Hope we can meet up sometime this year.

Lou

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Home of Slant6-powered fun machines since 1988

I will definitely meet up with you when I get this thing up and running.
I will try and make it to Wilkesboro to see the race, and I need to find a good 8 3/4 pig. (3.91s or 4.10s).


Joe

Make the NW race - you will not be sorry. Great cars, great people

I have a 4.57 pig I'd sell for an 8 3/4" axle if that is any help.

Lou

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Home of Slant6-powered fun machines since 1988

I only have small bolt pattern axles that I don't need. Let me know if those will work. I imagine that a 4.57 pig will really have the car's rpms at its limit going through the traps.

Joe

i just buttoned up my engine
during the rebuild I lined the dots crank/cam #1 piston all the way up.
had my brother watch the dist. button as i spun the crank to see if it went to the next firing order as that piston popped up.it did.
pulled dist. contunied rebuild.
Now when I tried to fire her up for the 1st time she pops back thru the carb.
is there a way to tell if i have the cam installed correctly
what can it be.
dist out a tooth??
mmmmhh??

any help much thanks.

Paul

Last time out I had 4.56's in my Valiant. It was turning on a 6000 shift light right at the MPH stripe.(1/4 mile)

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Official Cookie and Mater Tormentor.

Most likely the distributor is off time. Either off a tooth, or 180 deg out. Best way is to pull the valve cover and get the #1 piston at TDC (both valves "loose" lash). Then get the dist in so the rotor points at the #1 plug wire. If this is already the case, then you may just have to rotate the dist while cranking to find a better timing position. Usually popping through the car means you are too far advanced.

Also could be two plug wires reversed in the order.

Lou

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Home of Slant6-powered fun machines since 1988