Results of poor valve adjustment of 409 425 hp motor?

[Michael Cohen]

So this is the second time "the Beast" has thrown push rods. This time #8 cylinder. My mechanic says the thrown push rods are because the engine was over reved. That did not happen. I drove no faster than 60 mph and never "opened" the motor. Push rods replaced. Running again and now engine is running cooler! I am having another mechanic who is high performance specialist re adjust the valves. Any input please? Thanks Michael

 

[CDNpontiac409guy]

To where does it throw them ?
strange
Have you ever been able to find them ?
I don't think opening up the motor, would help you find the problem.

If you have already confirmed that the valve springs are correct, and they're not "stacking" at full lift, then just make sure that the lash is at manufacturer's spec. Too loose, can really "shock" the valve train parts. Too tight, and you'll kill lower RPM power, and risk burning valves.

 

[blkblk63ss]

Was they bent???? a friend of mine said back when he had a new 1962 impala 409 , he was bending push rod's so he took it to a well known mechanic in a dodge dealership:eek and supposedly he put in 348 push rod's cause he said they were bigger in diameter????? He said he never had any more bent , but still had to adjust when it was required. I don't know if that is 100% fact or fiction, just what he told me!!!!

 

[Phil Reed]

It's fiction Don!!! All 348 pushrods are 5/16" and high horse 409's are 3/8".

 

[62impala409]

I would lean towards the fiction side. The 348 motors only had 5/16" push rods. All of the 409 motors except the truck and 340 horse motors have 3/8" push rods. Bent push rods have been a problem for some going way back. The easy fix is to use the heavy wall or chromoly push rods. Leo

 

[Clyde Waldo]

I have had some experience with "thrown" push rods in W engines. My 1958 Impala 348 with a 250 horse engine that I drove from 1959 till 1962 never gave any pushrod problems. Traded it in on my 1962 Impala SS 409 with a 409 horse engine and I have to admit that I drove it a little aggressively in the three years that I owned it. I recall that I had a couple of occasions where I over reved and bent a pushrod. No real damage. That's the engine that I installed in the 409 powered 55 T-Bird in the mid 1960s and ran a few years with no problems. In the early 1970s I found another 409 that I bought in pieces. It had been bored 0.060 and I put a good solid lifter Crane cam in and it became the second 409 in the T-Bird. The second 409 in the T-Bird did 12.55 @ 110 mph but the first totally stock 409 in the T-Bird turned low 13s.

A few pictures to show what my x-wife did to T-Bird engine #2. I put up with her as long as I could but divorced her in late 1980 - took two years. During that time she took the T-Bird from where I had stored it and hid it. When the divorce was final I told her I was taking the T-Bird back (got to keep all my cars). Her reply was "bring a tow chain IT DON'T RUN NO MORE". (I sure admire you guys that chose your wife well the first time.)

I don't know how she accomplished the damage but I suspect she, just for spite, put the car in neutral and floored the gas till ............... . Did I say I sure admire you guys that chose your wife well the first time. The car sat for many years till I found this site and put 409 #3 truck engine in the T-Bird so I and my second wife Ellen could attend Thompson 2010. Ellen and I are looking forward to attending the Kansas event driving the T-Bird with 409 #4 - Ronnie's stroker.

 

[Michael Cohen]

To where does it throw them ?
strange
Have you ever been able to find them ?
I don't think opening up the motor, would help you find the problem.

If you have already confirmed that the valve springs are correct, and they're not "stacking" at full lift, then just make sure that the lash is at manufacturer's spec. Too loose, can really "shock" the valve train parts. Too tight, and you'll kill lower RPM power, and risk burning valves.

One bends like a question mark the other bends slightly look at prior posts the only difference this time was the push rod did not fall back into motor. all were found. only one was broken but i have been gentle this time push rod popped on a "cold" la morning about 45 degrees. i think a valve stuck and that caused the rod to bend.

 

[Clyde Waldo]

What rocker arms are you using?

I have seen stock rocker arms cutting into stock rocker arm studs.

What rocker arm studs?

Are the push rod guide slots in the heads worn?

Hope you find a fix for the problem!!!

 

[Tom Kochtanek]

Great story, Clyde! Fun, fun, fun 'til Daddy took the Tbird away .

The only time I've seen a bent pushrod in a 409 (so far) is when a guy tried to start and engine sitting to decades. Valves were probably stuck and pushrods became the weak link.

Best,
TomK

 

[blkblk63ss]

Did I say I sure admire you guys that chose your wife well the first time.

Well clyde i still have the first , but it's still not a bowl of cherry's as you may think !!!!!!~

 

[409newby]

Clyde I had one of those kind of wifes, I know exactly what you mean!

 

[k9hotrodder409]

Did I say I sure admire you guys that chose your wife well the first time.

Well clyde i still have the first , but it's still not a bowl of cherry's as you may think !!!!!!~

My wife Giny is #2 for 41 years now and still goin strong.
Her and I were out cruising back in the early ;90s in the '63 and we came up on a 66 GTO packed with high school kids at a light. I looked at Giny and Giny looked at me and she said "TAKE EM !!" Every one knows how a 425 horse 409 sounds when both carbs are open. The light went green and I just drove off slow so I wouldn't break the tires loose , brought it up to around 4 grand and shifted 2nd then 4 grand , 3rd 4grand 4th. Needless to say the GTO was in my rearview the hole time. All I could see was tire smoke. That GTO spun his tires like a top fuel dragster. We pulled over at the next light and waited for the guy . They pulled up behind me and got out. The guy looked at the fender emblems and said to me " WHAT THE HELL IS A 409 ??? None of those kids had ever seen a real live 409.. TRUE STORY.... Names were changed to protect the innocent.
I did have to adjust the valves when we got home. That engine sounded like a DIESEL!!

 

[blkblk63ss]

Well, not to get to far off of bent rod's ,when i was on my way to a evening national guard meeting back in the day with my 63 coming into the business district on a 4 lane, i had my then girlfriend with me , and i was in 3rd gear driving at a steady pace about 35 mph, a performance car got beside me , don't remember what it was ,and he was egging me on, so i quickly reached down to downshift to a lower gear ,my girlfriend put her hand on the shifter and kept me from shifting as i already had clutch disengaged and my motor reved up , and the other car took off. I was pissed and she was laughing her ass off. She was way ahead of me!!!!

 

[Michael Cohen]

What rocker arms are you using?

I have seen stock rocker arms cutting into stock rocker arm studs.

What rocker arm studs?

Are the push rod guide slots in the heads worn?

Hope you find a fix for the problem!!!

They are stock rocker arms. I don't know what are "rocker arm studs" Pic if you have one please. While i am at it has anyone ever used valve guides on a 409? And I've been single for 32 years. "Not that I'm against marriage, but marriage is an institution. Who wants to live in an institution!" Groucho Marx

 

[chevymusclecars]

Did you have the engine rebuilt and if so can you show us a copy of the work order showing what was done?

 

[64ss409]

They are stock rocker arms. I don't know what are "rocker arm studs" Pic if you have one please.

Photo of stud that the rocker arm is mounted on. These can get notches in the side allowing the rocker arm to c0ck off to the side. LOL, I had to use a zero in that 4 letter word or it looked like this ****.

 

[blkblk63ss]

These can get notches in the side allowing the rocker arm to-------- swivel------- off to the side

you have to get your mind off that other stuff when posting!!!!!!!!!

 

[Last 60]

Are the studs pinned or are they screw in studs? If not either, the stud could be pulling up out of the head and letting the lash go wacky.

Lonnie

 

[Michael Cohen]

Hello guys thanks for the input. The studs are screw in studs(look like bolts) Is it true that you cannot use the studs again once tightened down?
So a little history about the motor. Bought the project from Jim Verberren in Michigan. He had the engine rebuilt by Dynamic Speed and Marine in Chesterfield Mi. in 07. Motor sat because Jim's health turned sour. So I got the motor here with the car in 2011 Took awhile but got the car ready to run. When we started the roller rocker arms slipped of the valves when started up. Shut down motor. Pulled heads re built them. New everything. Stock lifters better valves supposedly better push rods. Did not change the cam or pistons. I had build sheets from Dynamic but now lost . Moved and papers lost in move. So motor sat for another year while paint and interior was done. So when ready to drive around I was returning to my mechanic and a bad noise. # 4 cylinder threw a push rod into the manifold and got stuck and bent. The other was bent. Prior pics somewhere on this site. Damaged #2 push rods so replaced those also. Drove around worried all this time about excessive heat so had engine carbs and timing redone. Set to specs 15 degrees and 32 degrees. Had carbs setup to run smooth. One morning a Sunday all ready to go to Pomona swap meet and I start up and immediately heard the same noise and I could tell running on 7 cylinders. Took it in My mechanic changed # 8 push rods. So I'm thinking the valves are set and lashed wrong. So today went to Westside Performance in WLA removed cover to inspect. Found lifters on three pistons not well centered a broken cracked plastic white oil seal (inside the spring) oil in spark plug. The worst thing according to Ted was that the spring tension (both springs) on 5 pistons was 145 0ne other was 155 two could not be measured because power brake booster was in the way. So this according to Ted is a potential time bomb for the cam. He said the spring tension should be no more than 110. Drove home as usual under 55 mph and have yet to "open" it up as my fear is something worse will happen. Took a few pics today. Will try to upload but I have difficulty with that and photobucket.

 

[CDNpontiac409guy]

Seems likely that the builder or others in the past with this ENGINE, have also had a number of stock 2X4 intakes in their possession ?