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I’m reassembling my 400SBC for the first time, complete tear down and reassembly after having some work done. Reading through Haynes I got a little confused so I just want to be sure I have this alignment correct.
In the book it says to put the camshaft dowel pin into the 9 o clock position. Then during the chain/sprocket installation and alignment I have to rotate the camshaft 180 degrees to get the timing marks to line up. My #1 and #6 cylinders are TDC and I don’t have the heads or lifters on yet. Is this in the right position? If I flipped the cam sprocket over then the camshaft dowel pin would be in the 9 o clock not the 3 o clock position but then I would not have a timing mark.
I know I have to put the metal washer clip thing under those bolts still but I just needed it to sit for a picture. Thanks!
No it’s not a new timing chain, should it be replaced, if so does the sprocket need to be replaced too?
How can you tell the Cam is in #6 TDC?
When I rotate the crank 1 full revolution, do I keep the timing chain connected or do I disconnect it and rotate only the crank?
Edit/Update: Is this what you mean? So they are both 12 o clock?
Last edited by Punkchachi; Mar 31, 2023 at 03:34 PM.
When the crank and cam sprocket dots are pointing at each other, the camshaft is in the firing position for #6. When you rotate the crank one full turn, the dots are both at 12:00 and the camshaft position is such that #1 is firing. This is just the way both components are timed with each other. My take on it is to align them dot to dot, torque the cam bolts, and then rotate to the 12's so #1 is firing before buttoning it up as it's a little more straightforward with dropping the distributor in.
Yes, I'd change the chain as long as you have it apart. It's inexpensive and good insurance. Buy the Cloyes brand as a chain & sprockets kit (~$50) - that way all wear in the existing sprockets is eliminated.
Do you know what the "12-13 100k" stamp on the cam sprocket means? If that's 100,000 miles in December 2013, I'd definitely be looking at replacing all three.
I'm not sure about the stamp. I bought the car a few years ago from someone who seemed reputable but since then I've only gotten to drive it a hand full of times. The guy really knew what he was getting rid of and straight up lied about what was inside the engine component wise. So, I'll just order new ones, I've learned a lot about this engine and I've enjoyed working on it, I just wish I could have driven it more before I had to tear it down.
No it’s not a new timing chain, should it be replaced, if so does the sprocket need to be replaced too?
How can you tell the Cam is in #6 TDC?
When I rotate the crank 1 full revolution, do I keep the timing chain connected or do I disconnect it and rotate only the crank?
Edit/Update: Is this what you mean? So they are both 12 o clock?
Yes....that is TDC #1
Yes....you replace the whole set....chain/gears
The Cloyes Street Tru-Roller pt# 9-1100 is an excellent value at $40.....
Thanks for the advice! Fate hath intervened. I had my lifters soaking in oil last night in a small tray, my wife moved them to get to something and they got knocked over. They all fell on the concrete and were nicked and mixed up. So I jumped on Summit and ordered a new Cam/Lifter/Timing chain/Sprocket kit. I got the exact same Cam/lifters I had and I saw that there was a kit with the chain/sprocket. I assume it is okay quality.
COMP Cams Xtreme Energy Cam and Lifter Kits SK12-250-3
-Cam/Lifters/Timing, Hydraulic Flat Tappet -Intake Duration at 050 inch Lift: 240 -Exhaust Duration at 050 inch Lift: 246
-Advertised Intake Duration: 284 -Advertised Exhaust Duration: 296 -Lift .507/.510
DO NOT soak your lifters in oil!
They will not bleed off and you will have hell trying to start it immediately as some of the valves will be held open....
You need Moly Paste on the cam and lifter foot....NOT on the side of lifters or the bore.....
NOT the red bullshit Comp gives you in the pack....
Moroso Moly Paste or equivalent.....
Prime engine for two minutes after you lash the valves.....
It is important to get the engine started right away....and break that cam in.....
Have your dial back timing light ready.....the rpm function will tell you where you are at....
2000-2500....fluctuating every 5 minutes for 20 minutes....
Others go longer but I never see the need.....
Timing Chain/Sprocket Alignment
