Finding TDC

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Steve Meltzer
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Finding TDC

Post by Steve Meltzer » Thu Jun 22, 2017 8:06 am

sounds like finding Nemo or Valhalla! Anyhow, can one use a "piston stop" tool to find exact (as possible) TDC? There's a plethora of examples of this for v8's on the 'net, but would this work with our vintage V12's? thanx. s
steve
meltzer, "“With a Ferrari, whatever it is, it’s a $1000. If that’s what it is.”"
'66 330 GTC, '72 Daytona-red, did they make any other colors?

tim
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Re: Finding TDC

Post by tim » Thu Jun 22, 2017 1:31 pm

Greetings... You can use a piston stop to find TDC on any engine with pistons that go up and down to find Sto-Vo-Kor.

Tim
1964 330GT 5769 -the big yellow taxi 61&66 Morgan +4's Daimler SP250 and some other dull stuff plus a brand new Mini Cooper S Clubman JCWS

Steve Meltzer
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Joined: Mon Sep 06, 2004 10:31 am
Location: with Barney the Beagle boy and Enzo 8995

Re: Finding TDC

Post by Steve Meltzer » Thu Jun 22, 2017 4:44 pm

Thanx for the confirmation and the schooling about Sto-Vo-Kor. I've been fighting (valiantly) with this GTC engine for nearly a year...does that make worthy to enter Sto-Vo-Kor? s
steve
meltzer, "“With a Ferrari, whatever it is, it’s a $1000. If that’s what it is.”"
'66 330 GTC, '72 Daytona-red, did they make any other colors?

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tyang
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Re: Finding TDC

Post by tyang » Thu Jun 22, 2017 8:35 pm

Hi Steve,

O.K. What are you up to now? Is "PM/1/6" not good enough for you? What are you trying to accomplish? There are very accurate ways to find TDC, but you may not need to. Tell us what you're trying to do, so we can help.

Tom
'63 330 America #5053

tim
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Re: Finding TDC

Post by tim » Fri Jun 23, 2017 4:34 pm

Greetings... I agree with Tom. I can't imagine what would make the PM marks move. If they were on a damper with a rubber mount, they definetly need checking. I've not checked my Ferrari but have done so on the Morgans and several others. Just what are you up to.

Tim
1964 330GT 5769 -the big yellow taxi 61&66 Morgan +4's Daimler SP250 and some other dull stuff plus a brand new Mini Cooper S Clubman JCWS

Steve Meltzer
Posts: 880
Joined: Mon Sep 06, 2004 10:31 am
Location: with Barney the Beagle boy and Enzo 8995

Re: Finding TDC

Post by Steve Meltzer » Fri Jun 23, 2017 5:32 pm

Well, it's been nearly a year since I (foolishly) decided to pull the engine on the GTC and hopefully, fix the oil leaks. I've done a couple of 'Vette engine R&Rs, and I knew this would be a bigger deal by far. No disappointments. The heads weren't removed, and I've done everything I can to keep the engine at TDC....all kinds of reference marks. Over the months that have elapsed while I was being sucked deeper and deeper into the known vortex of this sojourn, I would carefully rotate the crankshaft and always two rotations to keep it at TDC.

This past weekend, with some professional help (no not my shrink!), I got the timing chain cover back on, water pump, tensioner, etc. The cam marks are right where they were, at the "0" mark. I thought that as confirmatory data, i'd check the valve timing on #1, but they were way off, instead of being dead on. So that lead me to wonder if somewhere on the road I'm off a full rotation or a tooth or?? It could be that my valves were just set incorrectly from long ago, and my assumption about the valves was wrong. (While writing this, I see that if I were off a full rotation, the exhaust valve would be open and the intake valve should have the correct setting for being closed.)

I also thought that if I could determine the TDC for every cylinder, I could set the valves in an optimal way....my mathematical preferences + OCD would really like it this way, as opposed to the method of watching the rockers to see when the valves are open and closed. As the pictures show, the engine stand my helper made is very, very robust and allows for great access to the engine's front and the ability to rotate the entire engine, but the bracing at the rear precludes access to the rear main seal (so that will be done in the sling, I suspect) and timing marks on the flywheel are, well, on the wheel which is on a cart in the garage somewhere...can't be mounted at this time. I could wait to set the valves until the car is back in the car, but this would be so much easier and controlled.

And that's the truth, so help me Enzo. s

ADD: I'm really happy (so far) that I've done this, as I've learned a great deal and have enjoyed working along at my own pace; getting great, helpful advice from several folks on this site. Not quite ready to give up my day job, but I'm makin' progress, and some of it's forward. s
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steve
meltzer, "“With a Ferrari, whatever it is, it’s a $1000. If that’s what it is.”"
'66 330 GTC, '72 Daytona-red, did they make any other colors?

Jumprun
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Re: Finding TDC

Post by Jumprun » Fri Jun 23, 2017 11:00 pm

Hi Steve so how can you find TDC with no flywheel or distributors and the heads in place?

How about this, turn engine upside down, at the point of max travel of the rod cap
or piston toward the head, and with both valves closed, this will be TDC of the compression stroke. Maybe rig up a dial indicator to get a reading.

Steve Meltzer
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Re: Finding TDC

Post by Steve Meltzer » Fri Jun 23, 2017 11:21 pm

Tom, Thanx. The engine is upside down at this moment, and I have a dial indicator (which I hate, 'cause it's always a matter of some sort of rigging to get to do what it supposed to do!). More later. s
steve
meltzer, "“With a Ferrari, whatever it is, it’s a $1000. If that’s what it is.”"
'66 330 GTC, '72 Daytona-red, did they make any other colors?

tim
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Re: Finding TDC

Post by tim » Sat Jun 24, 2017 2:23 am

Greetings... Steve, your best bet is to find some way to put the flywheel on. Those marks will be accurate.

Tim
1964 330GT 5769 -the big yellow taxi 61&66 Morgan +4's Daimler SP250 and some other dull stuff plus a brand new Mini Cooper S Clubman JCWS

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tyang
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Re: Finding TDC

Post by tyang » Sat Jun 24, 2017 7:01 am

Hi Steve,

I agree with everyone else. Put the flywheel on, and all will be clear. The dowel pin will only allow you to install the flywheel only one way, so you can't screw that up. I'm hoping you parked everything on PM 1/6 before you took the timing chain off! If not, don't turn anything until you unbolt the rocker stands to close all the valves. With the cam released, you can turn the crank to TDC, and then set the cams to their approximate PM 1/6 mark found near the front rocker stand. Install the timing chain.

PM 1/6 will arrive twice as you know, once on the exhaust stroke, and once on the compression stroke. On the compression stroke, you should see the marks on on the cam shaft line up at PM/1/6, but remember, these marks were done at the factory when everything was new, and not accurate when the timing chain is adjusted over the years. As the slack in the chain is taken out by the adjuster, the cams will rotate away from the TDC marks found on rocker stands. How to get the valve timing dead nuts correct is for Ferrari Class 201!

Tom
'63 330 America #5053

Steve Meltzer
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Joined: Mon Sep 06, 2004 10:31 am
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Re: Finding TDC

Post by Steve Meltzer » Sun Jun 25, 2017 10:41 am

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Tom, yes I did "park" the whole shootin' match at TDC (PM 1/6 index marks on the compression stroke, right distributor pointing to plug wire #1) from the start and, as noted, was as careful as I could be, not to screw that up. I'd forgotten about the indexing dowel pin on the flywheel, so thanx for that reassuring reminder. I was more concerned that I was off 360°, than one tooth. Anyhow I made a piston stop tool courtesy of someone on youtube. (took an old sparkplug, cut the electrode off with a cut-off wheel, broke the ceramic in a vice, then drilled out the guts. Used some M8 "all thread" as the adjusting rod, and, because I didn't want to bother cutting threads within the plug, I just used some of a Texas favorite, "JB Weld", to fix an M8 X 1.25 nut to the top of the plug...and viola (intended, self-forced error), I now have piston stop tool!) Here's a picture of that.

Then I removed the threaded rod so I had a spark plug with no guts, cut the finger off of an old exam glove <G> to make a small balloon, wire-tied it to the plug and I was ready to test the #1 cylinder. Indeed, when the engine nearly reached it's previously set marks (on the rear, near the crank's rear main seal) the little balloon began to take on air from the compression stroke, confirming that I was approaching TDC. I realize that this does not set TDC at dead nuts, but it does prove that my previously set marks are still valid for TDC. When I get a bit closer to the final button up and setting the valves I'll hone in on it more precisely. (Ferrari Engines 201). As noted, I've really sort of enjoyed foolin' around with this, and only wish I was being paid by the hour.

Please don't email me that you think my blown up little balloon has some hidden Freudian meaning.

steve
steve
meltzer, "“With a Ferrari, whatever it is, it’s a $1000. If that’s what it is.”"
'66 330 GTC, '72 Daytona-red, did they make any other colors?

tim
Posts: 309
Joined: Tue Sep 03, 2002 2:48 pm
Location: sacramento, ca

Re: Finding TDC

Post by tim » Sun Jun 25, 2017 5:05 pm

Greetings.. And with that length of all thread you'll never loose it.


Tim
1964 330GT 5769 -the big yellow taxi 61&66 Morgan +4's Daimler SP250 and some other dull stuff plus a brand new Mini Cooper S Clubman JCWS

Steve Meltzer
Posts: 880
Joined: Mon Sep 06, 2004 10:31 am
Location: with Barney the Beagle boy and Enzo 8995

Re: Finding TDC

Post by Steve Meltzer » Sun Jun 25, 2017 6:14 pm

yep...bigger and longer is better, right? (at least according to ace Ferrari mechanic, Hugh Hefner) s
steve
meltzer, "“With a Ferrari, whatever it is, it’s a $1000. If that’s what it is.”"
'66 330 GTC, '72 Daytona-red, did they make any other colors?

afwrench
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Re: Finding TDC

Post by afwrench » Mon Jun 26, 2017 4:49 pm

Hi Steve, just for future reference . If you put the rubber glove on the end of the tail pipe and it gets real big you then know that the engine is indeed running. Mike
72,365gtc4,14681,2007 599 GTB

Steve Meltzer
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Re: Finding TDC

Post by Steve Meltzer » Mon Jun 26, 2017 5:25 pm

been a long day so your humor was most welcome! s
steve
meltzer, "“With a Ferrari, whatever it is, it’s a $1000. If that’s what it is.”"
'66 330 GTC, '72 Daytona-red, did they make any other colors?

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