![]() |
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?:icon_saywhat: :DBeav |
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... |
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 |
1 Attachment(s)
Originally Posted by Beav
(Post 7838218)
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 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. |
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.
|
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. |
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 |
Like anything, the first one is the hardest...
(and quite often, the most rewarding!) Just take yer time, you'll be ridin before ya know it! |
| All times are GMT -5. The time now is 11:17 AM. |
© 2026 MH Sub I, LLC dba Internet Brands