I posted this in my Cam Cover post and it probably didn't get read so I'll do a fresh post. 1. Is it safe to make a TDC tool that screws into the number one plug hole that has a 5/16 bolt to stop the piston say 20 degrees on either side of TDC so I can establish true TDC with all the slack out of the rotating assembly. I'm a little worried about the valves (intake or exhaust) hitting the bolt sticking down in the combustion chamber (Hemi and all that). We did this routinely in my drag racing days and never had a problem but I would hate to clip a valve. I can use a dial indicator instead if necessary, however, I just like the positive stop better. I need to know where actual TDC is as I am going to degree the cams to insure all is OK and since I installed the PerTronix ignition module (2 modules in rear dist) I want to insure the ignition timing is correct for both cyl banks. The ignition lead (advance) is a bit of a problem as with out the retard micro switch it's been a little difficult to get a stable idle speed of 1K or a little less with the AC on.I've got is set at 34 degrees at 5K now and its idling OK. Back when it was my daily driver, 25 years ago, I ran a little more lead, 38 degrees, which I am unable to do now without modifying the advance curve as there is to much lead at idle making the idle a little fast even with carbs as closed as I can get them. 2. This is just me being lazy. I plan on checking the clearance on all 16 valves and , of course, those that are within tolerance leave alone. So my question is, is it OK to remove all the shims for the valves that need adjustment at the same time, documenting adjustment required as well a shim thickness, and still rotate the engine without the shims in place. The cams would, I assume, hit the top of the cam follower buckets. My fear is doing this could possibly damage the cams! My goal is to have all the shims for the valves that require adjustment out of the engine so I can possibly use some of them. Just a thought. Thanks
NO !!! DO NOT ROTATE the engine Without the shims in place. The cam WILL 'mar' the empty shim bucket.
Barry, What EXACTLY is the problem? Do you need a valve replacement shim Spreadsheet Calculator? I got one if you need it. Measire the valve lash, measure the original shim thickness and PRESTO it gives you the replacement shim max/min thickness range.
I made a piston stop from a spark plug and a bolt just like you describe. I certainly used it on my QV without and issues and I'm pretty sure I used it on my 2V car also.
Thanks guys. No problem. I was hoping to Adjusting Valves 1. Check and document clearance on all 16 valves. 2. Don't touch any valves / shims that within tolerance (if any). 3.Remove / Number / Measure each shim that needs different thickness. 4.See which shims I can move around to provide proper clearance. 5. Purchase shims as necessary. I have been advised by mwr4440 (above) not to remove all the out of tolerance shims at once as rotating the engine would be required causing possible damage to the cams / shim buckets. So I will do them one at a time noting the shim thickness for the ones I remove looking for one of the proper thickness for the vale I'm working on. Thanks for the Fiat chart. The shim thickness is calculation easy enough. As far as the cam timing goes I want to degree the cams with a degree wheel to insure all is as it should be. It's no big deal but I would rather use a piston stop rather than a dial indicator as I believe it's more accurate and pretty much bullet proof. Since I've install the PerTronix MRII it no longer breaks up at high RPM, like it did with the 30 year old points, but seems to flatten out above 6K. Ignition timing is spot on according to the flywheel marks and the advance (I cleaned and oiled the advance mechanism) appears to working correctly although I haven't had it checked with a distributor machine. I did a compression test a while ago and all four front cylinders were a little low but equal which makes me suspect that one or both of the front cams is one tooth retarded. I've changed the cam belts two or three times since I've owned it and don't think I made a mistake but who knows and I don't know what was done by the PO. Actually it's amazing it runs as good as it does after sitting for 27 years. Thanks again Barry
Do you know how many miles the shims have done, imho you need to check and measure so they are within tolerance but also remove to inspect if they are worn out, the hardness material is only microns thick and do wear out. In any event I always flip over the shim or replace. Only flip over the shim if you are sure they havent done any miles. Its relatively easy to distinquish between a used shim face and a new one If not and to protect expensive cams i now always change considering the cost of the items. A good service log should tell you your current status. Tony
Where are you Barry? If UK I can lend you a set of 100 shims, just pay Post and £5 for any you use. Derek (in London)
Tony It has about 70 K miles on it. My daily driver from the 1970's til 1992 when I parked it. There are no service logs (I do all maintenance on my cars), other than the owners manual maintenance log which has no coupons filled out., I bought it at a distress sale from a local Pontiac dealer who didn't want to deal with it as the carbon canister screen / filter had ruptured resulting in carbon plugging all the carb idle circuits. The local Ferrari dealer wanted 8K to start working on it because it ran so terrible (apparently not actually diagnosing the problem) . Took me a day or so to diagnose the problem and clean the carbs after which it ran fine. Not understanding exactly how the emissions / carbon canister worked I had to do it again a couple of weeks later. As everyone who had dealt with a carbed car is aware it will pop back through the carbs a little when cold which puts pressure in the carbon canister and with out the filter carbon gets pumped into the air cleaner and carbs. I don't believe the forward bank has ever had the valves adjusted as I adjusted the rear bank at about 30K. It was so close, only requiring two shims one size up, I didn't bother, probably a mistake, to adjust the front bank. I will, of course, check each valve shim to insure it looks good and is not "hollowed" out. If there is any question I will replace all of them but until I get it apart and documented I don't know what size to buy and the available shim kits generally have 2 of each size which may no work out. I know this replay is long but I looking for comments about any potential pit falls. Thanks Again Barry
Thanks Barry, no problem, yep its one of those PITA jobs. I started to document the shims service so when i get to do it next time i have sort of idea where i am. I use the fiat X1/9 33mm shims on both my cars as they dont have the Ferrari tax on them Yes they are a pain to get hold of and even when you measure and fit the new one it doesnt quite do it, Some charge as much as £10 each for them but these guys at just £3 each its worth buying a few extra either side of your required shim. https://www.eurosport-uk.net/shop/index.php?main_page=product_info&cPath=1_7&products_id=45&zenid=396683c09l8m8oak1nqr9verl1
Derek I'm in La La land (So Calif). Thanks for the offer, let me see how it goes. Tony Yup the price seems to vary a bunch. In fact it seems the Volvo 240 shims also fit. Thanks Guys
The Fiat crowd maintains a shim exchange: https://xwebforums.com/forum/index.php?threads/reminder-valve-adjustment-shim-exchange.32787/ and they’re also available new from the standard Fiat suppliers: autoricambi, Midwest-bayless, vick autosports, fiatplus.
Ehamilton Thanks for the web site. There doesn't seem to be any difficulty getting shims. Its just to bad I can't go to the local parts stores and buy them as I'm doing the adjustment. When I did this the first time, 2 1/2 decades ago, I just popped down to the local Ferrari parts / repair shop and had everything finished up the same day. I actually used to drive a 74 X/19. Many fond memories except the trips through the desert in the heat of summer with no A/C. Three engines (broken timing belt, blown head gasket between cylinders) and a 100K plus miles later I gave it to the gardener. Barry
From my notes Volvo 240 shims are compatible. I have got them from the local Volvo dealer here in Raleigh. I have not considered rotating the engine with a shim removed. I usually do all the measurements, once, twice, or thrice. Then I remove the cams entirely as I usually replace the cam seals during this service. After installing the new shims I measure again for good measure.
If you're planning on replacing the cam seals anyways, this is the easiest way to do it (and with the cams out you can comfortably use a piston stop to find TDC which was one of the original questions in this thread). Check all the clearances, note any that are out of spec, then pull the cams, check the thickness of the old shims and calculate what the new shim has to be to be back in spec. But don't trust the thicknesses printed on the shims when you're calculating the new shims - mike the old, use that to calculate the thickness you need in the new, then mike the new to verify that it's what you need.[/QUOTE]
[/QUOTE] Thats a good point, i found quite a few that were printed incorrectly after head scratching why my maths was so bad.
Mic OLD and NEW. NEVER TRUST ANYTHING. I have yet to find a SINGLE Shim that was marked 100% CORRECTLY, IF you measure to 0.001mm AND damn few if measured to 0.01mm.
Here is an Excel Automatic Replacement Valve Shim Calculator for 2Vs ONLY.* Metric (Millimeters) and Imperial (Inches), just pick the correct TAB at the bottom. The sheet is Protected. Password upon request via PM. Just CAREFULLY and ACCURATELY FEELER GAUGE the Gap/Lash between Cam Heel and Shim, and MIC the Old Shim, and then Plug-in those two numbers into Columns 'B' and 'C' and the Calculator will tell you what thinkness range to look for IAW the Workshop Manual. Ill post its 'Sister' Spreadsheet that graphically shows you how to Adjust or 'Re-Pin' the Cam Gears and Cam Shafts and Move those relative to the belt, to 'Time' or 'Index' your cams to the valve events BTDC or ATDC within +/- 1° in a few days. READ the Notes at the Bottom of this Spreadsheet for the definitions of the Automatic Color Changes- GREEN, YELLOW, RED. * - I am working on a much improved version that will ALSO 'Do' 4V cars too. It'll be 'Awhile' though.
