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-   -   noise after valvetrain disassembly (https://67-72chevytrucks.com/vboard/showthread.php?t=225147)

dave2953 01-28-2007 11:00 PM

noise after valvetrain disassembly
 
I posted a few days ago about a noise I've been chasing for quite some time. I thought it was a collapsed lifter, so I checked all my lifters and found nothing unusual. I took two of the lifters apart (stupid idea) and couldn't get them back together. I should have taken Ragenrats advice and got a new cam and lifters, but instead I bought 2 lifters and reassembled. I have a really nasty knocking sound and none of my pushrods are getting oil. Even before the teardown, oil was only running off the rockers, not squirting out like I've seen other trucks do. I have ~40 psi oil pressure and let the engine run a few minutes, but the noise made me nervous so I shut if off. Sorry for the long post, but I'm at my wit's end with this noise and ready to take it somewhere and let someone else deal with it. Thanks in advance! :confused:

screamin_eagle 01-28-2007 11:07 PM

Re: noise after valvetrain disassembly
 
shouldnt have replaced just the two lifters

screamin_eagle 01-28-2007 11:10 PM

Re: noise after valvetrain disassembly
 
three o fives are junk anyway

dave2953 01-28-2007 11:11 PM

Re: noise after valvetrain disassembly
 
I thought about replacing all of them, but I would have had to replace the cam too, correct? I've never swapped a cam before and thought I might not break it in properly.

FarmTruk 01-29-2007 01:19 AM

Re: noise after valvetrain disassembly
 
Quote:

Originally Posted by dave2953 (Post 2007427)
I thought about replacing all of them, but I would have had to replace the cam too, correct? I've never swapped a cam before and thought I might not break it in properly.

Well, you might get a chance to try it now...:hm:

Sorry 'bout your engine probs. I don't believe 305's are junk. They're just misunderstood. Seriously...its still just a SBC, same as all of 'em.

I am of NO help with fixing your problem, but you might want to post this in the Engine forum. Lots of folks there to help, and some of 'em don't always cruise this forum.

Best 'o luck to ya...:)

Morgsie 01-29-2007 02:15 AM

Re: noise after valvetrain disassembly
 
Quote:

Originally Posted by screamin_eagle (Post 2007423)
three o fives are junk anyway

Bull ****. Soft cams aside, they are durable motors motors. ~420 000 km on a 305 that's never been rebuilt. Clearly junk.

brak 01-29-2007 02:26 AM

Re: noise after valvetrain disassembly
 
Quote:

Originally Posted by Morgsie (Post 2007738)
Bull ****. Soft cams aside, they are durable motors motors. ~420 000 km on a 305 that's never been rebuilt. Clearly junk.

:agree: I had over 250k on the stock 305 in my camaro when i pulled it. I only pulled it because I ignored the drippy waterpump a couple days too long, which finally died at 85mph on the freeway. hell i was still able to drive the damn thing 2 miles home, and it started every time i needed to move it after the head gasket blew. :rolleyes:

dave2953 01-29-2007 09:44 AM

Re: noise after valvetrain disassembly
 
Originally it had a 307, and everyone where I lived told me that motor was junk, too. It only lasted 37 years, what a piece of crap.:)
Anyway, after I get home from school I guess I'll have to take it back apart and see what the noise is. It sounds like it's coming from the bottom end, but I can't be certain. Also, I noticed one of the pushrods (#7 intake) doesn't come up as high as the others. Is this most likely a collapsed lifter??

MotorSeven 01-29-2007 10:21 AM

Re: noise after valvetrain disassembly
 
Dave,
Did you have the heads off? It took my 250 about 5 min to get oil back up after i put the head back on. Pour some oil on the valve train from the top side and try it again. It also made some really strange noises(kind of a suck/knock sound) for about 10 min until the oil was getting to everything. If it's knocking, are you sure the valves were set right? I had to set mine twice, the first time i had a valve a little off and with it tapping, i couldn't find it before oil was pumping eveywhere. So i shut it off, went back to TDC on #1, and set them all again, turning each up to TDC by hand, tightinig until the push rod wouldn't spin, then 1/4 turn. That should get you close enough to get it running for a final setting.
RD

Richard H. 01-29-2007 10:41 AM

Re: noise after valvetrain disassembly
 
1 Attachment(s)
Quote:

Originally Posted by dave2953 (Post 2007857)
Originally it had a 307, and everyone where I lived told me that motor was junk, too. It only lasted 37 years, what a piece of crap.:)
Anyway, after I get home from school I guess I'll have to take it back apart and see what the noise is. It sounds like it's coming from the bottom end, but I can't be certain. Also, I noticed one of the pushrods (#7 intake) doesn't come up as high as the others. Is this most likely a collapsed lifter??

I showed you this once before about your lifter not coming up. The pic shows a lobe wore off , just one of three. The lifters were cupped enough to drink shots out of.

dave2953 01-29-2007 02:50 PM

Re: noise after valvetrain disassembly
 
I went at it again after I got home and the noise I was hearing was caused by a couple of valves being too tight. It went away after I loosened the rocker nuts. I let it run for awhile and oil finally started coming through the pushrods. I blew them all out when I had it apart. She seems to be running well now. Thank you all for your input and suggestions! This is an awesome board!

Morgsie 01-29-2007 11:37 PM

Re: noise after valvetrain disassembly
 
I have a 305 I'm my Impala, it had unknown mileage when I got it, but I'm going to assume it's between 220-240km. Anyway, the guy gave me his word it was a quiet motor. Before putting it in my car, I replaced rear main seal, oil pan gasket, new timing chain (had the original composite gear in still), put a speedy sleeve on the balancer, resealed the intake and rebuilt the carb. It fired right up but to my dismay there was ticking. I should have put a new cam when I had everything apart but hindsight is 20/20 plus I didn't have that much cash at the time.

A year later I finally had the cash and the time to change the cam. The cam was pretty much pooched. After I removed the intake I turned the motor over by hand. The lifters were barely moving. Removed the cam and sure enough, more than half the lobes were rounded. Replaced the cam and new lifters. Make sure you sock your lifters in motor oil (totally submerged) for ~15 minutes, or at least until bubbles stop comming out. I've heard of guys that don't do that and they lifters never build up oil. Sometimes you get lucky, sometimes you don't. I also replaced my almost non existent valve stem seals, spent a day removing valve springs and cleaning the visible part of the valve stem with steel wool and varsol. This was to prevent dirt and sh*t going through and doing damage to the valve guides. I also washed the valve spring, retainer, keepers and rocker arms for good measure (same process). I haven't driven the car yet (waiting for window seals), but the ticking is gone, no more blue smoke on startup, it has a much nicer exhaust note to it and hopefully it'll burn less oil. As brak said they are a misunderstood motor. IMO, they are an excellent daily driver motor (for a V8 anyway), which is why I put it in my Impala. You can also do different gearing and whatnot to waken them up a bit as well. I put a new torque converter and 3.36 posi in my car this time around, I can't wait to drive it again!

BTW, the cam I put in was a 300HP 327 cam (stock). I paid around $150-$175 CDN for the cam which came with lifters and all the required gaskets. Guess I'll see in the next couple of weeks if it was a good selection or not.


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