Post a reply to the thread: 454 bbc ring break in procedure and oil help
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Thanks for that. I'll invest in a leak down tester..... At the same time my gut tells me i need to take it out for a good run. Get a couple hours on it then change the oil again. I'm thinking only half the cylinders rings have seated, maybe they don't all seat at the same time.... I've only got maybe an hour on it, and it's never seen the secondaries yet. I don't know, maybe my compression test was premature.
You would be better off doing a leak down test on each cylinder. Leak down tells you much more. First put some heat in the motor so the rings expand, etc. Basically you roll a cylinder over to it's TDC (both valves shut and piston to top of bore) and you fill the chamber with compressed air. They gauge will tell you the % of air leaking and you will be able to hear the air passing somewhere. If you hear air coming out the carb, then your intake valve isn't sealing. Out the exhaust pipe, then you have a exhaust valve issue. If you hear air coming up through the valley of the motor or out the dip stick tube, then it's getting by the rings. Ideally you don't want any air coming out any of the valves. Valves should seal 100%. Air will get past the rings, it's just a question of how much. You can get a cheap leak down gauge for under $50. The nicer ones are in the $150-$200 range.
From what I've read those compression numbers are low. I called the machine shop that did the short block for me and he wasn't much help, told me to squirt oil in the cylinders and if it improves, its the rings, if not, its the valves, he's the same guy that did the valve job too..... He's Vietnamese and hard to talk to, been in business 30 years and he's got a good reputation so I don't know what the problem is with him not helping me. Figures. So I'm going to get an oil bottle and redo the compression tests. I'm using a harbor freight compression tester....screw in type.
I run water into the nozzle when I did start it a couple times to check the push rod guide adjustments that I did. I only ran it 5 seconds each of those times, if that, and didn't have to hit high rpms for that. I meant to say when I ran it on trailer when I initially set the total timing that I noticed the vibration, probably more like 3000 rpms.
x2. That jet pump's life is getting shortened quite a bit if you are running that thing up that high on a consistant basis on the trailer.
If this is a jet boat I hope you have the pump disconnected if revving to 4000 rpm
I just did my first compression test on cold engine, a week after my 2nd run. I've got 120 on half of the cylinders and 90 on the other half. My guess is that those cylinders that are at 90, the rings aren't seated..... Also all the spark plugs are clean except for #8, which has 120 compression. What does all this mean? I also notice when I ran it on trailer a vibration somewhere between 3000 or 4000 rpm's, that I don't remember being there before. Thanks in advance.
Cylinder break down
1 - 120 .............. 2 - 90
3 - 90 .................4 - 90
5 - 90 .................6 - 120
7 - 120 .............. 8 - 120
Number 8 plug on left, #6 on right, and all the rest look like #6.
Roller rockers would have less friction which could possibly lead to more power. There really isn't a set HP number you increase by the change. Stock rockers will also only handle so much lift, so when you upgrade to a bigger cam, you will have to go to aftermarket rockers no matter what.
Then I'll get adjustable push rod guides lol. I wonder why the heck it was so far off to begin with. Makes me wonder about the valve guide or valve guide bore. I have no idea. What's benefits of going to roller rockers, a bit more horses? Do I need to change anything else when doing so?
Glad to see you got it worked out. Now watch, when you upgrade to roller rockers it will be off in the other direction again!
Success! I removed the guide plate and widened the holes just a bit. Put it back together. Started it up for a few seconds and shut it down. Checked them, they look good to me. The intake moved to center and the exhaust moved just a hair off center. I'm happy with it.
Thanks guy's for the help.
have used these "adjustable guide plates " with good success cheap @ $45 bucks
Won't slotting the holes on the rocker stud side throw off the adjustment on the exhaust side ?
Originally Posted by BGMAN This is a good thread!
I'm glad to hear Barry's trick did help getting the rocker lined up. Instead of taking it off and opening up the hole more, I would look into taking some material away from where the push rod comes through the plate. I feel like opening up the mounting hole will just make it "sloppier" and increase the risk of it moving around on its own and throwing the alignment off again. I think enlarging the hole is actually a better answer, since you do want the guide plate to guide the pushrod, unless you remove some material and use a punch to close the gap back up in the correct direction.