How far did you back off the rockers? Running for only 3 or 4 seconds and then fading out with a backfire at the end sure sounds like your lifters pumping up from oil pressure and holding all your valves open.
How far did you back off the rockers? Running for only 3 or 4 seconds and then fading out with a backfire at the end sure sounds like your lifters pumping up from oil pressure and holding all your valves open.
Have you verified that you have not wiped the cam? This can happen on initial start up. Why cam lube is so important. Especially on SBC.
i'm down with Vigo
I will try backing the rockers off more
In reply to Twisted46 :
Run them out at least a full turn, too loose at this point is not going to matter. This is not final valve adjustment time. Something else I hear you saying is it idles for a short bit. The last thing you want with a new cam is running at idle, get the rpms up to 2500 or whatever your cam company wants. Get the rpms up and check timing that it is not too far advamced, then work on your cam break in. If the valve train is noisy from being too loose, your not going to hurt anything at those rpms. Idling a new cam is a good way to wipe out new lobes.
In reply to Fladiver64 :
I will try that. I too am very worried about cam health at this point. And while the motor has ran for less than 30 seconds total I have been turning it over a lot.
Quick update, I backed rockers off another 1/4 turn or so and i noticed the motor got harder to turn by hand. I set the timing at 12BTDC, rotor on the leading edge of post #1. It took a few tries with the clutch and starting fluid but I fired up and idled on its own until I pulled ignition after 10-15 seconds. I have a friend coming over to help me set timing and rpm then i will put water in it and finish cam break in.
Hopefully that is all it was I am back to having some PR wiggling but no noticeable noise
In reply to Twisted46 :
"got harder to turn by hand" = "valves seating properly and holding compression in cylinders"
i'd back em all off another 1/4-turn and get the rest of it ready to run long enough to break in the cam.
good work!
Congrats!! Now you can get to the fun part!
clicked on this thread to see if you were running yet, was not dissapointed!
Great job.
+1 on the back the adjuster s off another 1/4 turn . We have all been in your shoes, good job sticking with it, feels great went it finally works!
Thanks again guys. I will back them off some more. I guess new lifters are easy to overtighten.
I'll get a video up so you all can see your hard work pay off.
Also watch for more posts about my build of you guys arr interested in an SBC powered 260z track car. Actually driving this thing with the V8 is going to be nuts!
Sorry it took so long, engine broken in with new oil. Sounds happy to me:
https://drive.google.com/open?id=1AovLfAtmztKdfcW1GYPYeF5wHJ2F3Uv0
Sounds good to me!!
Good lord. What’s that thing weigh? 2000#? It’s gonna pound on late model Vettes in the straights at least.
Car weights about 2300 with the SBC in it. Come Spring I will get some 30+ rolls recorded as I am guessing anything under 30 will just result in tire smoke. Right now I could probably spin tires in 5th a 60 with how cold it is.
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