That is fine! As long as the engine will crank at 17* initial hot, no problem at all. Now limit the vacuum advance to 8*. Run it off manifold vacuum. You will then idle at 25*, and cruise on the highway at about 40*. That will get you best MPG, and the engine should run much cooler at idle and low speed. Adjust the spring preload in the cannister (with the allen wrench) so that you don't get any part throttle ping when you hammer it from 60 MPH. That's it.
argh, can't find the paperwork for the limiter plate, is each notch 2*? edit: yes, according to the paperwork: http://www.cranecams.com/pdf/254g.pdf
I'm thinking you are using the limiter plate like described in the Crane instructions. Forget that completely. I want you to affix the limiter plate to the cannister arm, like in this picture. If you don't know how to do that, send me an e-mail to the address in my signature. I will send you instructions and pictures.
ya, have mine setup like that too. is there a measurement from some point as to where to put the set screw? like to confirm that I have it installed on the vacuum can arm in the correct spot. but I guess if I have it installed so that when it is closed it touches the arm then thats probably the right spot. will send email with my addy, if you have something written up it would probably be good to review just to be sure. very motivated to remove all guess work and get this right once and for all. 8* = 4 notches, si?
interesting - my plate hits the arm on the advance plate and not the bent arm on the vacuum advance can. ie. it doesn't slide under the plate like it seems it should, not enough clearance. my crane vac adv unit is marked with "AS-11" suggestions? edit to add: just pulled the vac advance out and comparing it to the photos you sent/posted I have an extra metal plate attached on the area where the plate screw goes in, thats my blockage, will pull it off
You may need to use a lower profile screw, or clearance to base of the distributor where the cannister mounts.
just noticed the gouge on the arm in the photo above, looks like the screw was binding the movement of the advance as well
took plate off, installed washer to get screw out of the way (not sure it was, may not have removed arm when I drilled the hole), set the max travel on the vacuum advance to .106. started over again just to be sure that the lip/plate combo on the vac adv unit were not causing overall probs with the advance plate, put the yellow springs back in, rpm back up to 1800, advance still at 32*, all is good. put blue/silver springs in, set idle at 700 in park. buttoned it back up off for a test ride, fingers crossed
went well overall, good news and bad news bad news: still have some pinging under load coming up hill, have played with vac can adjustment, currently 12 turns out good news: the good news is that there is no real bad news. no problems with hot starting. probably some additional playing around to do but I have a much better handle on making adjustments. the vac can limiting plate was installed incorrectly, now resolved. the vac can was not hooked to manifold vac port, now resolved. the total timing was off, now resolved. I own a fancy new timing light that will help out from this point fwd. am more smarter now. thanks again for all the help, very much appreciated. I'm def. on the way to a better running truck. taking the boat to the lake this afternoon in the heat for some additional 'testing' under load while towing.
You may need to limit the amount of vacuum advance some more if you cannot adjust the spring preload with the allen wrench to eliminate part throttle ping. Sometimes, I find that it is better to modify a stock cannister because the spring is much stronger on those. You want the spring in the cannister to pull all the vacuum timing out when the engine is under load. Manifold vacuum is much better than ported IMHO. It instantly responds to changes in throttle opening where ported may lag a bit in response. Keep experimenting with the total timing, spring changes, and and cannister limiting until you find what the engine wants. Good Luck.
hey larry i followed your instruction on timing ,but when i lock up the brakes and stomp it to the floor the engine will hesitate or bogg down, then it revs on up and smoke the tires.what do you think the problem is ? hit me back a.s.a.p. :idea2:
Larry - I was PM'd and asked about the block off I used in my MSD. It's 22 degrees outside, and as I remember, was one of the worst installs ever. SO! I did the next best thing, cut one out of paper and took a picture of it. :TU: To all who need to make one, here it is. You will have to tweek it some to fit, but this is the general way to make it. The mounting hole is 3/16". I used a dremel tool to grind the proper depth for my results- Good Luck
There are lots of ways to accomplish the same thing. I kind of like the one idea of using the links from a bicycle chain to fashion a block off plate (Post 153 on page7 of this thread)
Here's a picture to support Landsharks note #31 on the numbers below the timing plate. You can see the advance limit slot is longer on the left one. The one on the left is stamped 520 and the one on the right is stamped 718. The 520 is from distributor number 1112109 and the 718 is from distributor number 1112006. I also noticed that the counter weights are much larger on the 1112006. Ernie
After having studied this very interesting thread for quite some time now, I finally found the guts to get to work. I have the mr Gasket kit and my distributor is a pure stock one (455 from 73)<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com<o></o> <o></o> Some follow up questions;<o></o> <o></o> Can the vacuum canister be removed with the distributor still in the engine? I have removed the two screws but I dont seem to be able to get that pin to slide out from the hole <o></o> The vacuum canister should be reduced to only add like 8-10* advance right, how and when is the best way to measure that? <o></o> My engine has run 135k miles but seems very well maintained, is there any reason to believe that my distributor would be too worn to be re-curved with a good result? The 0-mark on the balancer stays steady at idle when using a timing light<o></o> <o></o> Thanks in advance!<o></o> <o></o>
Per, It can be difficult to remove the canister from the distributor, but it can be done while the distributor is still in the engine. It may help to apply vacuum to the cannister. It may give you a bit more wiggle room. You can use an awl or small screwdriver to push the pin out from the top. You can measure the distance with feeler gauges or use a drill bit or nail that you have measured with a micrometer or caliper. The important part is to restrict the amount the pin moves to .086 (8*) 0r .104 (10*). Measure it any way you like. As long as your timing mark is steady, and the dwell stays relatively steady as you rev the engine, the bushings in the distributor are probably fine.
