You don't absolutely have to remove them all, it just makes the motor easier to turn and prevents it from "rocking back" against the compression of a cylinder.
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You don't absolutely have to remove them all, it just makes the motor easier to turn and prevents it from "rocking back" against the compression of a cylinder.
To find TDC, take off the tappet cover and turn the engine til the exhaust is closing and the intake is opening. When they're equal, that's split overlap. With the great majority of cams, that's TDC (but half a turn out on the distributor). Then check your HB timing marks, they should read zero. If you have your cam specs, that'll tell you how much it will be off zero.
While I agree with this method for getting close to TDC, there are factors which might keep you from getting exact TDC.Quote:
Originally posted by R Pope
To find TDC, take off the tappet cover and turn the engine til the exhaust is closing and the intake is opening. When they're equal, that's split overlap. With the great majority of cams, that's TDC (but half a turn out on the distributor). Then check your HB timing marks, they should read zero. If you have your cam specs, that'll tell you how much it will be off zero.
1. The ability of the operator to determine exact split overlap by the naked eye without the use of a dial indicator. (not likely)
2. The assumption that both rocker arms are the exact same ratio (not likely)
3. The assumption that there is zero slop in the timing chain/gears (not likely)
4. The assumption that the builder installed the cam straight up, neither advanced nor retarded. (not likely)
5. The assumption that the cam specs are available (not likely)
6. The assumption that the hot rodder doing this possesses a level of expertise in math (not likely)
On a 6" diameter damper ring, a movement of only 0.052" equals 1 degree, so it doesn't take much to be off by several degrees.
I still contend that the best way to find exact TDC on an assembled motor is the piston stop method.
No one seems to stock piston stops around here so I have to wait for UPS to bring me one. Thanks for all the recommendations. I think I can get as close as anyone else using the piston stop and measuring the distance between the two marks and finding TTDC.
You can make a piston stop out of an old spark plug.
Getting the porcelain out without damaging the steel shell can be tough, but it can be done.
A little welding and you're done.
You can also make them from a spark plug extender - available on the KD tool rack - that is used as an anti-plug fouling device in a cylinder that's pumping oil.
The one in the pic was drilled to tap size and a - fairly sure - 3/8-NF tap spun in for the adjuster bolt.
Round off the bolt end and observe the cautions put forth by the other guys when you use this device.
I've done the same thing with an old spark plug, except I found that it was just the right size for a 3/8-NC tap and I had some 3/8-NC allthread laying around. Like you said, I rounded off the end and voila, a no-cost piston stop.Quote:
Originally posted by C9x
You can make a piston stop out of an old spark plug.
Getting the porcelain out without damaging the steel shell can be tough, but it can be done.
A little welding and you're done.
You can also make them from a spark plug extender - available on the KD tool rack - that is used as an anti-plug fouling device in a cylinder that's pumping oil.
The one in the pic was drilled to tap size and a - fairly sure - 3/8-NF tap spun in for the adjuster bolt.
Round off the bolt end and observe the cautions put forth by the other guys when you use this device.
I changed the spark plugs and wires so I have 8 to practice on. BTW, what would cause the old plugs to look "white, ashy"?
Correction: I have 7 to practice on. One of them needs to be right!**)
OK, that could contribute to the elevated operating temp. Will be troubleshooting the Edelbrock some more. May need the calibration kit with the metering rods and springs. Mo' money, Mo' money!**)
Update:
Got the piston stop ordered. Should arrive by Wednesday. Still troubleshooting fuel starvation problem on another post. Decided to order stop instead of creating one out of old plugs.
:D
Just like a redheaded schoolteacher I used to date, she kept makin' me do it over and over 'til I got it right :LOL:Quote:
Originally posted by s10streeter
OK, that could contribute to the elevated operating temp. Will be troubleshooting the Edelbrock some more. May need the calibration kit with the metering rods and springs. Mo' money, Mo' money!**)
I wanted to have one of these in my toolbox just in case any one around here ever needs to find TTDC I can show them the tool that no one else has around here. Then explain to them how it works and then give them the name of the tool. We hillbillies are easily enfluenced by another persons knowledge. Not to mention having a rare tool. This could make me famous!:LOL: :LOL:
:confused: Or, at least, boost my ego.:LOL:
Quote:
Originally posted by s10streeter
OK, that could contribute to the elevated operating temp. Will be troubleshooting the Edelbrock some more. May need the calibration kit with the metering rods and springs. Mo' money, Mo' money!**)
Instead of ordering the calibration kit - which costs a few bucks and you have a lot of lefotover, probably never needed parts, go to the Edelbrock site, see what the stock rods and jets are, decide how you want to jet it, then order those specific rods and jets + a spring kit from Summit.
(Keep your eyes open at the swaps, you can get a calibration kit with 90% of the parts within and the price can be reasonable.
I got a kit at the 2nd of July swap meet for 10.
Only trouble is, the kit covers my friends carb - that needs to be jetted for our altitude - and most of it is too small for my bigger engine and carb set-up.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A quick and dirty stop can be made from a long reach spark plug . . . assuming yours isn't a long reach to start with.
The piston stop arrived today.
There are no instructions with it. Does it matter how far the bolt is screwed in?
Does anyone know what size socket fits on the crank so I can turn the engine with a bar?
Yes, I am being lazy.:LOL:
The more I can stay out from under the truck. The more time I have to admire its beauty from the top. :LOL: :)
""Does it matter how far the bolt is screwed in?"""
Just tighten the outer shell down snug so it will not move. You don't have to torque it or anything.
Remove the #1 spark plug. Turn the motor over with a breaker bar and socket on the harmonic balancer retaining bolt head clockwise in the direction of rotation until a friend feels air being pushed out the spark plug hole with his finger or thumb. When you are about an inch from the timing mark on the damper, stop and insert the piston stop, turning the inner threaded rod down against the top of the piston. Don't try to torque it, just contact the piston. Make a mark on the damper ring at the timing pointer. Now turn the crank back the other way (counterclockwise) all the way around until the piston is again coming to the top of its travel and stops against the piston stop (which you haven't moved). Make another mark on the damper ring at the timing pointer. Halfway between these 2 marks is absolute TDC. Measure carefully. It works best if you use a 6 inch caliper.
Hey tech,
Whats the bolt size on the crank? Come on, I know you have the answer, Please?:confused:
:LOL:
Ok, I quess I'll have to do it the hard way. I'm going to GMPP.com!:LOL: :LOL: :)
3815933 Crankshaft Bolt
This 7/16-20 x 21/4" bolt positively retains the balancer and pulley on the crankshaft snout. For all small-block V8s and V6/90º engines with tapped crank snouts.
Hopefully this means 7\16 and all sbc are the same?:o
:CRY: Fiddle Faddle!CRY:
You should not turn the motor with the crank bolt, it could break
or pull the threads out! 5/8 socket fits most!
:confused:
Is there any other way to turn an engine by hand?
Remove the flywheel cover and you can turn the flywheel
I could not time my 454 with my sears advance type tmining lite bought another one and got the same results with a reading that was showing some 55* at idle and vacuum adv off. turned out the damper had slipped on the rubber mount and had to change out the damper puilly. Checked it with a home made tool to find true tdc on compression. ed ke6bnl
Thanks ed,Quote:
Originally posted by Ed ke6bnl
I could not time my 454 with my sears advance type tmining lite bought another one and got the same results with a reading that was showing some 55* at idle and vacuum adv off. turned out the damper had slipped on the rubber mount and had to change out the damper puilly. Checked it with a home made tool to find true tdc on compression. ed ke6bnl
thats the general direction I'm heading in. Noticed the water pump weeping a little so I'm gonna go ahead and replace it and get things out of the way to get to the balencer and pulley.
First of all, I would like to thank everyone who replied to this thread to help me along, you guys are great.
I followed the advise from y'all and set the timing marks today.
I could actually turn the engine with my hands after pulling 4 of the plugs so that worked out good.
Turns out that after marking the HB in the two places and then taking a caliper and measuring the space (0.7520) and dividing by 2 (0.3760), I ran the caliper back to .3760 and placing my mark, the original mark WAS off almost 1 1\2 inches! Thats a bunch of degrees. No wonder I was having trouble timing this thing. Then I made sure that the rotor was close to firing #1 at about 4deg. BTDC and cranked it and check the timing and now I can actually set it a 12deg BTDC and run it with no problems. Also got the new pump on and reduced the amount of antifreeze and running more water and it is running cooler, about 8 degrees. This was quite a hurdle for me and I got discouraged at times but you guys stuck with me and helped me to the end so hats off to the CHR members!:) :) **) :D
I'm VERY pleased with you. clap, clap, clap, clap, clap, clap, clap, clap (that's applause). And you should be very pleased with yourself now that you know how to do this. You'll be able to amaze others with your knowledge from now on. :) :) :) :)
Now, let's carry this one step further to find out how many degrees it was off. Let's assume it's a 6" diameter damper ring. To find the circumference of the damper, we'll multiply 6 times 3.14159 (pi) and get 18.849". Now, if we divide 18.849" by 360 (the number of degrees in a circle), we find that one degree on the damper ring would measure 0.05235". Now, using your estimate of 1 1/2" of slip, we'll divide 1.5 by 0.05235 and find that the damper ring had slipped more than 28 degrees, 28.653295 degrees to be exact. :)
For the rest of you fellows out there who want to nail down TDC like streeter did and also make a mark where you want to set your advance, here's how. Follow the instructions in this thread like he did and find TDC, then center punch the damper ring and put a spot of white or yellow paint in the dot so your timing light will pick it up easily. Now figure out what 1 degree is on the ring with the math I have outlined above. If you want to set initial at for instance, 12 degrees BTDC, move to the right of your TDC mark and center punch the ring again, using a dot of paint. For instance, using the 6 inch ring example, 12 times 0.05235" would be 0.628", so using your dial caliper, move 0.628" to the right of your TDC mark to center punch the advance point.
I'll do another example with an 8" ring. 8 times 3.14159 is 25.13272". Dividing 25.13272" by 360 equals 0.069813" for each degree. If you wanted to move 12 degrees ahead of TDC for your timing point, you'd multiply 12 times 0.069813" and find that you want to move 0.837756" (rounded off to 0.838") to the right of TDC to make your center punch mark.
Now, the last thing on this subject is that if the damper ring has slipped already, it's probably going to slip some more. The only thing to do is to replace the damper or have your damper rebuilt. These guys will rebuild your damper to bulletproof for about $50 for a small block Chevy damper.....
http://www.damperdoctor.com/
:)
Thanks for the encouragement Tech,
It turned out to be rather simple once I calmed down and concentrated on what I was trying to do. You're right about the calipers. They get it dead on.
FYI- the reason that I turned the engine by hand was that the retaining bolt backed off when I tryed counter clockwise rotation. Are these bolts not tourqed down? The assembly didnt seem loose, saw a keyway, are these HB pressed on? The 3 pulley bolts were good and tight.
Yeah, the damper retainer bolt is supposed to be torqued down, it's just that the torque required to turn the motor over exceeded the hold-down torque which had been applied to the bolt by the person who installed it.
With all the plugs removed, it shouldn't require more than about 35 ft./lbs. of breakaway torque to rotate the motor. If more than that is required, something's bound up.
you did good! :toocool: