Engine guru's direction needed!!

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Jan 27, 2011 | 08:39 AM

Beav

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Road Warrior

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From: North Georgia

Engine guru's direction needed!!

Got a question for you guys.
'99 RKC injected TC88
Getting rid of those tensioners, going Andrews 26's with gear drive. Gonna remove the heads also and have them cleaned up a little.
Here's where I'm at.
Got all the "extras" off the engine. The rocker box covers are off, and I was told that the engine needed to be set a #1 TDC. Okay....
Manual states each cylinder need to be TDC when releasing rocker assbly. Okay...
So, I started with #2 and removed #2 rockers assbly and pushrods. Set the engine up for #1 @ TDC (which is where I want to leave it)
Now I've got to thinking....
After I get the cam plate off, I need to check the runout on the crank to be sure it's in spec. Hell...ya gotta spin it to do that!!!
Do I take the rocker assbly off of #1, remove the camplate and do the runout check before taking the heads off?
How to find #1 TDC on COMPRESSION stroke if ya don't have the valves moving for refference?
Have I already screwed up?

Beav

Jan 27, 2011 | 10:17 AM

CroK

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Spin it with rear wheel, tranny in 5th gear...

Watch the intake lifter. Intake is the one closest to the cylinder (inner lifter bore on the lifter blocks). When the intake lifter is on the rise, or high side of the cam lobe, the piston will be dropping. Once the piston begins to rise again, on the compression stroke, the intake lifter will be on low side of the cam. Now watch the piston, or put a plastic straw in the cylinder. When the piston is at it's highest point, that is TDC for that cylinder. Repeat for the next cylinder...

Last edited by CroK; Jan 27, 2011 at 10:20 AM.

Jan 27, 2011 | 10:42 AM

Beav

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Road Warrior

Joined: Apr 2010

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From: North Georgia

Thanks Crok...
Got that down. Engines @ #1 TDC now.
Question is...
Gotta get the cam plate off. Doesn't that have to be done to check crank runout? Doing the runout means turning the engine.
Once the runout is performed, how do I know that I'm at TDC on the compression stroke? Won't have the valvetrain moving anything...or am I missing something? I tend to over analize things...
Is there a way to tell TDC marked on the crank etc?
First time inside the VTwin, so I'm new to this stuff.
Thx
Beav

Jan 27, 2011 | 01:21 PM

djl

HDF Community Team

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From: san antonio

Quote:

Originally Posted by Beav

If I understand your post, you seem to think that the piston needs to be at TDC to check crank runout? Continue with the teardown and remove the heads. When the heads have been removed, use a couple of 1/2" PVC pipe couplings and the head bolts to secure the head to the case. If you don't plan on pullling the cylinders, you need to secure them so you don't disturb the seal between the cylinder and the case. (see photo).

Measuring crank runout should be done with cam plate off. So, pull the cam plate, check runout and proceed. No need to worry about finding TDC again until you adjust pushrods. Previousl posts include that information.

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Jan 27, 2011 | 05:14 PM

DTTJGlide

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From: North Cental Iowa

You don't have to worry about #1 TDC, the cams are what dictate that, as long as you have #1 piston at top of stroke you install the cams as instructed & you will be at #1 TDC. The crank doesn't know whether it's on compression stroke or exhaust stroke until the cams are installed.

Jan 27, 2011 | 09:14 PM

CroK

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Yep, what they said...

Remove the cam support plate/cams and do the crank runout check. The part about setting up on TDC was to release any pressure from open valves/compressed valve springs. When you are removing or installing the rocker assembly, the pressure from the valve spring is transfered to the rocker assembly and could cause parts to warp or maybe push the last few threads out of the head(s). At TDC, both valves are closed and lifters are on low side of the cams, all tension is released allowing safe disassembly or assembly of the valve train.

Follow the manual to align cam/crankshaft sprocket timing marks, then using TDC again as the point where you set the pushrod adjustment.

Last edited by CroK; Jan 27, 2011 at 09:21 PM.

Jan 27, 2011 | 09:40 PM

Beav

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Road Warrior

Joined: Apr 2010

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From: North Georgia

She's all apart now, appreciate the help.
Packed up and off to the machinist tomorrow. No big deal for many guys who've done it a thousand times, but I'm pretty stoked right now. Got to look inside and see what's where. Now if I can just get it all back together and make her fire!!!
Thanks again

Beav