470 push rod length questions

[natemoore]

First of all, I'd like everyone to know that I've successfully recovered from hip resurfacing surgery and that I am "born again hard" (I'm only 47). I'd like to give a special "shout out" to BZtugger1960 for coming all the way down from Minnesota to cut my grass while I was recovering from surgery. Iboats.com members are special. He's still camped in the backyard, BTW.

Any-who. I've had a pesky problem with the #1 intake pushrod. Back on Dec. 17th (the day before my hip resurfacing surgery) I got my 470 started after a complete overhaul. That pushrod bent. Unfortunately, I couldn't "get bent" myself due to my hip surgery.

Well, today, I replaced the bent pushrod after verifying that the valve moves up and down freely, in accordance with advice from my machine shop mechanic. The engine turned over in about half-a-turn and ran superbly until that telltale hiccup. I pulled off the valve cover and discovered that the aforementioned pushrod was OUT FROM UNDER THE ROCKER ARM, BUT IT WAS NOT BENT (I rolled it on a piece of glass to confirm this).

I began to suspect that I installed a too-short pushrod, seeing that I reinstalled a standard length pushrod and got greater than .11" but less than .21" in clearance (how I made this mistake I'll never know because I double and triple checked the valve clearances while the engine was on the stand).

Question: will a pushrod that is too short also cause the above problems?

 

[natemoore]

Re: 470 push rod length questions

Did I mention my hip resurfacing surgery?

 

[bomar76]

Re: 470 push rod length questions

deleted

 

[solar7647]

Re: 470 push rod length questions

I dont think a short push rod would have even stayed in place after being installed. It would have been loose.

Have you reinstalled it and seen what the cleance was?

Edit: I would agree with the above stament that the lifter may need replaced, it may be stuck in the collapsed position and not recoiling to keep pressure on the rocker.

 

[natemoore]

Re: 470 push rod length questions

I dont think a short push rod would have even stayed in place after being installed. It would have been loose.

Have you reinstalled it and seen what the cleance was?

Edit: I would agree with the above stament that the lifter may need replaced, it may be stuck in the collapsed position and not recoiling to keep pressure on the rocker.

Yeah, I reinstalled a STANDARD length rod and remeasured the clearance. It was within the spec range. I haven't fired up the engine with the standard rod yet. I'll do that tomorrow afternoon.

Originally, I had the shortest pushrod installed, but I'm beginning to think that I didn't have the lifter completely compressed when I took the measurements.

All new lifters are installed.

 

[solar7647]

Re: 470 push rod length questions

Yeah, I reinstalled a STANDARD length rod and remeasured the clearance. It was within the spec range. I haven't fired up the engine with the standard rod yet. I'll do that tomorrow afternoon.

Originally, I had the shortest pushrod installed, but I'm beginning to think that I didn't have the lifter completely compressed when I took the measurements.

All new lifters are installed.

Now that make sence....The explination suggested that the push rods that came out from under the rocker was standard size. Now that I think some more on it I geuss if the lifter was all the way up and so was the valve it would keep the rod tight untill the lifter droped....then it would come out of place...........so my offical answer is yes to the origional question!

 

[zbnutcase]

Re: 470 push rod length questions

There really isn't a "standard" length, the required length is determined by the gap between rocker and valve stem with lifter fully collapsed should be .110-.210

 

[natemoore]

Re: 470 push rod length questions

There really isn't a "standard" length, the required length is determined by the gap between rocker and valve stem with lifter fully collapsed should be .110-.210

A fine point. I should have said a "none" in the hierarchy of color codes, with red being shorter than "none" and blue and yellow being longer than
"none."

 

[solar7647]

Re: 470 push rod length questions

A fine point. I should have said a "none" in the hierarchy of color codes, with red being shorter than "none" and blue and yellow being longer than
"none."

The details will kill you every time! I took standard lenth as to get proper rocker gap.


Any ways saw you signiture....digging the picture.....I am a reaaly big RUSH fan.....I have seen them 5 Times!!

 

[natemoore]

Re: 470 push rod length questions

The details will kill you every time! I took standard lenth as to get proper rocker gap.


Any ways saw you signiture....digging the picture.....I am a reaaly big RUSH fan.....I have seen them 5 Times!!

I named my son Geddy. Got an awesome Starman tattoo. Have you heard the news about their upcoming tour? They're also working on a new album.

 

[natemoore]

Re: 470 push rod length questions

Okay. Found the problem. Not related to pushrod length at all. #1 intake valve is getting stuck. Won't even slide down into the cylinder on it's own; I've got to give it a whack and a good shove to get it to go down. Plenty of grey powder built up around the guide. Hole is oval, not round.

I'm very disappointed in my machine shop. All that hard work. Now I have to remove the head, take it back to them in hopes they get it right this time, and eat the costs of the head/intake/exhaust gaskets.

If I installed a cabinet that fell off the wall and crushed a customer's iPod, it is reasonable to expect that I should replace the iPod. Should this machine shop provide the new gaskets for me since they screwed up the valve job?

 

[guyaverage]

Re: 470 push rod length questions

I named my son Geddy.

But... "Geddy" isnt Geddy's real name! Its "Gary"... Wait, I'm sure you probably already know the story. I've seen them probably 40 times since the early 80's...

I doubt the machine shop will pay for the gaskets, and a Merc headgasket for this engine isnt cheap either.

 

[natemoore]

Re: 470 push rod length questions

But... "Geddy" isnt Geddy's real name! Its "Gary"... Wait, I'm sure you probably already know the story. I've seen them probably 40 times since the early 80's...

I doubt the machine shop will pay for the gaskets, and a Merc headgasket for this engine isnt cheap either.

Yeah. I know the story. I sometimes call (my) Geddy Gary with a yiddish accent as a joke. Remarkably, it comes out sounding like Geddy.

You don't have to tell me how expensive those Quicksilver gaskets are. Got one with less than 30 minutes of run time under that cylinder head. I didn't figure the machine shop would own up to its screw up.

 

[natemoore]

Re: 470 push rod length questions

Ahhhhh....the machine shop is already working on its story: apparently it's my fault. He told me that he thought it may have rusted in place since four months went by from the time they rebuilt my head to the time I fired it up and got the first of several bent push rods. True, maybe I shouldn't have cleaned the head in gasoline, dried it with compressed air, then let it it outside in the rain for four months. My bad.

Here are some pictures of the oval shaped hole in the valve guide. The valve won't even rotate 360, nor will it come out. I haven't used a hammer yet.

The oval part is on the bottom of the valve stem. Kinda hard to see, but it's there.

 

[solar7647]

Re: 470 push rod length questions

I dont see how rust would make a metal obejct go from round to oval!

If you plan on re-using the valve once you get a new guid I dont think a hammer will be a good chouse. Do you have a bench press you can use to push it out?

 

[natemoore]

Re: 470 push rod length questions

I dont see how rust would make a metal obejct go from round to oval!

If you plan on re-using the valve once you get a new guid I dont think a hammer will be a good chouse. Do you have a bench press you can use to push it out?

I'm taking the head back to the machine shop this morning. Let them figure it out.

I got the head off without too much trouble or disassembly. Time-wise it'll just cost me a couple of afternoons. I guess it could be worse.

 

[solar7647]

Re: 470 push rod length questions

I'm taking the head back to the machine shop this morning. Let them figure it out.

I got the head off without too much trouble or disassembly. Time-wise it'll just cost me a couple of afternoons. I guess it could be worse.

I would be made as hell if i was you.... i hope they fix it for free

 

[natemoore]

Re: 470 push rod length questions

I would be made as hell if i was you.... i hope they fix it for free

They fixed it for free. He installed a new valve and double-checked the others. He said it was "galling" probably do to oil starvation for some unknown reason, but he rarely sees it on an intake valve.

When I primed my oil pump, I visually confirmed that oil was coming up through all the pushrods, so I'm not sure if that's the reason. Whatever. He's a nice guy and didn't give me a hard time about it.

I'm in the process of putting it all back together.

 

[natemoore]

Re: 470 push rod length questions

There really isn't a "standard" length, the required length is determined by the gap between rocker and valve stem with lifter fully collapsed should be .110-.210

According to Mercruiser Service Bulletin 89-29: "Listed below are the latest part numbers, color code and size of the push rod in relationship to the standard
length."

No biggie, but since you brought it up......