| Author | Message | ||
| Bill Sebestyen (Bill308)
Member Username: Bill308 Post Number: 311 Registered: 5-2001 |
Verell, I could have gone larger than 8-inches. I'm pretty sure 11-inches is ok. I put different patterns on each side and could mount the degree wheel either way by just flipping it around and putting the screw/washer assemblies in from the other side. The top picture highlights the timing events in color while the bottom one has 360, thin, degree lines.   The paper faces are getting a bit scruffy now and the adhesive is failing, but they can be easily renewed by just printing, cutting, and readhearing new paper faces. Maybe next time I'll try some transparency film instead of paper. Humidity causes the paper to swell over time. | ||
| Verell Boaen (Verell)
Junior Member Username: Verell Post Number: 250 Registered: 5-2001 |
TO RETURN OR NOT TO RETURN SUMMIT RACING TIMING 11" WHEEL KIT? Bill, Thanx, Clamping to the O.D. of the pulley is what I was looking for. I've got a Summit Racing 11" O.D. timing wheel kit with indicator, stops, etc. Do you know whether or not there's clearance to use an 11" wheel on the damper pulley, or was ~8" the largest wheel that clears everything? I don't mind modifying the wheel to fit the pulley's O.D. But, If there's not enough clearance, I want to send it back to Summit & exchange it for another kit that has an 8" wheel. I ordered the kit expecting it to come in while I had my timing bearing replacement project underway. However, it was back-ordered & arrived after I had the car back together. Now My son has a car tieing up my lift, so it's not convenient to pull the wheel/fender liner & do a trial fit. | ||
| Bill Sebestyen (Bill308)
Member Username: Bill308 Post Number: 310 Registered: 5-2001 |
Verell, I didn't find a degree wheel that I thought would work so I fabricated one. It's made with about 0.080 inch thick aluminum plate that I cut to have an id of about 4 5/16 inchs (a snug fit on the od of the damper) and an 8 inch od. The id fits snugly on the od of the damper. The od gives 1 degree increments of about 1/16 inch. A piece of fine wire with a flattend and sharpend tip was clamped to a frame rail. To keep the degree wheel aligned on the damper, I drilled and tapped four machine screws at about the 4-7/8 inch diameter distance. A fender washer under the head of the screw, extending over the id, contacts the face of the damper and provides positive axial location. A piece of masking tape secures it for rotation. This configuration allows the engine to be turned by the damper retaining bolt without disturbing the degree wheel. Degree marks and diameters were obtained by printing a full size pie chart, divided into 360 degrees in Excel. The paper chart was cut out and fixed to the aluminum degree wheel with spray on contact cement. TDC, BDC, and useful information was added to the pie chart using text boxes. The degree wheel took me the better part of a day to make with hand tools but worked really well. If you decide to give this a try I could email you a copy of the Excel file that creates the face and marks the diameters. | ||
| Verell Boaen (Verell)
Junior Member Username: Verell Post Number: 248 Registered: 5-2001 |
Bill 308, DEGREE WHEEL TIPS WANTED: What size degree wheel did you use? Where & how did you attach it? In particular, is there a way to attach it to the crank damper pulley on the front of the engine so you don't have to open up the flywheel area. | ||
| Edward Gault (Irfgt)
Intermediate Member Username: Irfgt Post Number: 1765 Registered: 2-2001 |
You could never tell by the way an engine runs if it is off even several degrees. I have seen Hondas and Toyotas off a whole tooth and still run pretty good. There was once a Factory proceedure to advance the cams on Fiat 131s a tooth to eliminate surging. | ||
| Mitchell Minh Le (Yelcab1)
Member Username: Yelcab1 Post Number: 262 Registered: 11-2001 |
I used a dial indicator set at the top of the piston. I found two lower points below TDC and split the difference. The reason I asked this is because all cam shafts are lined up to the mark I found which is off by 1 degree compared to the flywheel mark, which in itself can be off by 1 degree due to tolerance. In order to make any adjustment now, I have to pull the valve covers, see if the marks lined up, if not, then I have to mess with all the cam shaft pulleys to adjust it by 1 degree. I am less inclined to do this for obvious reason. | ||
| Bill Sebestyen (Bill308)
Member Username: Bill308 Post Number: 308 Registered: 5-2001 |
I had good resuslts using a degree wheel and a dial indicator, fixed in the spark plug hole. I took my readings with the crank pin approaching 90 BTDC, from both directions. This cancels out any clearance issues. This method enabled the degree wheel to be set with great precision. I was able to determine my PM 1-4 mark was within 1/4 of 1-degree of where it should be. I estimate my measurement tolerance was within +/- 1/4 degree. I now feel confident using the factory timing mark for all other timing events. | ||
| Paul Newman (Newman)
Member Username: Newman Post Number: 317 Registered: 12-2001 |
I would think a positive stop combined with a degree wheel is the only way to find TDC correctly. A reading on the piston crown wont cut it because of the crank pin swing at TDC. | ||
| Steve Magnusson (91tr)
Member Username: 91tr Post Number: 912 Registered: 1-2001 |
Mitchell -- I too was surprised that there wasn't some more positive form of angular registration between my ex-308-2V flywheel and crankshaft. If the flywheel is stubborn and shifts a little when you tighten it down, you can always move the reference pointer to compensate (i.e., if everything's physically at TDC and tight, just make the marks line-up) | ||
| billy bob (Fatbillybob)
New member Username: Fatbillybob Post Number: 3 Registered: 8-2002 |
How are you finding TDC with the dial indicator? Some people do this wrong. | ||
| '75 308 GT4 (Peter)
Intermediate Member Username: Peter Post Number: 1937 Registered: 12-2000 |
I wouldn't say too critical, but if you can dial it in now and be absolutely sure of TDC, then by all means do it. In the end though, the way Ferrari has set-up timing on the flywheel is far better and more accurate than domestics/imports who time off the front pulley. | ||
| Mitchell Minh Le (Yelcab1)
Member Username: Yelcab1 Post Number: 261 Registered: 11-2001 |
During the assembly process, I used a dial indicator to find TDC on number 1. Now that everything is attached including the flywheel, I found that the TDC mark on the flywheel is off by 1 degree. Further, the slop on the flywheel / bolts is such that I can position flywheel by about 1 degree with respect to the index mark. How critical is this 1 degreee slop? |