Frankenstein is giving me trouble...

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Dodge72

Dodge72

Odd one out
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Oh surprise, I need more help lol.

Here it goes. 92 Roller LA block, gone through a basic once over with the machine shop with a 030 overbore. Roller cam :

20190807_183601.jpg


Estimated 9.3:1 compression with Speed Pro H116 pistons. I did not have the original 308 heads with this block so I had a pair of 596 heads rebuilt to stock specs with Comp 901 springs.

My valvetrain angles look horrible. I've been struggling to measure for proper pushrod length. First, pushrods didn't clear. I had the pushrod holes hogged out to 9/16s by the machine shop. Now, the stock pushrods barely clear (my pushrods checker tool doesn't...), but now I have these issues. Note the contact patch from rocker arm to valve, and the angles of pushrods from the lifters.

20190930_163131.jpg
20191006_125008.jpg
20191006_122152.jpg


This can't be right, can it? It is worse that I can't even clear a pushrod checker tool without it rubbing on the bottom of the pushrod hole. I can't drill them out further or it'll go through the castings. The first picture is when I installed the rocker shaft and the pushrod checker and rotated the engine twice. I made sure the shaft was in the correct orientation and rocker arms on the right sides. I even switched them on the other side to see if I got a different result, I did not. Of course, when I pulled the pushrod checker I realized it got slightly bent at one point. Attempting this with a stock pushrod I still got the same results.

I'm kicking myself for not realizing the differences between roller and non roller heads and I spent a good bit getting these rebuilt. I'm half tempted to just save for the right heads instead of fighting these and spending more money on these. If anybody has any ideas, please let me know. Thank you!
 
Dodge72 said:
Oh surprise, I need more help lol.

Here it goes. 92 Roller LA block, gone through a basic once over with the machine shop with a 030 overbore. Roller cam :

View attachment 1715406738

Estimated 9.3:1 compression with Speed Pro H116 pistons. I did not have the original 308 heads with this block so I had a pair of 596 heads rebuilt to stock specs with Comp 901 springs.

My valvetrain angles look horrible. I've been struggling to measure for proper pushrod length. First, pushrods didn't clear. I had the pushrod holes hogged out to 9/16s by the machine shop. Now, the stock pushrods barely clear (my pushrods checker tool doesn't...), but now I have these issues. Note the contact patch from rocker arm to valve, and the angles of pushrods from the lifters.

View attachment 1715406739 View attachment 1715406740 View attachment 1715406741

This can't be right, can it? It is worse that I can't even clear a pushrod checker tool without it rubbing on the bottom of the pushrod hole. I can't drill them out further or it'll go through the castings. The first picture is when I installed the rocker shaft and the pushrod checker and rotated the engine twice. I made sure the shaft was in the correct orientation and rocker arms on the right sides. I even switched them on the other side to see if I got a different result, I did not. Of course, when I pulled the pushrod checker I realized it got slightly bent at one point. Attempting this with a stock pushrod I still got the same results.

I'm kicking myself for not realizing the differences between roller and non roller heads and I spent a good bit getting these rebuilt. I'm half tempted to just save for the right heads instead of fighting these and spending more money on these. If anybody has any ideas, please let me know. Thank you!
Click to expand...
I wasn't aware that the geometry was different between the two heads? I can definitely see different push rod sizes..
 
due to the taller hydr. roller lifters / shorter pushrod the pushrod angles are worse in these engines compared to the flat tappet cammed ones.

Michael
 
I got a buddy of mine that is going through this same thing. He finally went back to the original heads. If there’s a fix I’d like to know what it is
 
You have to grind the pushrod holes in the heads to an fro.
Slot them the direction of interference top n bottom.
That or drill 9/16 and then only a little grinding is required. That only works if the pinch isn't really ground on.

Pull'em and grind'em.
You can kinda see what I'm describing in this pic of one of my j heads.

View attachment 1715406795

20181109_142444.jpg
 
Are there right and left rocker arms? Maybe intake/exhaust? I don't remember as it's been a long time since I used stock rockers.
 
If it were me, I'd just go back to a flat tappet cam and move on.
 
Looking at the picture both rockers need to move to the left like the wide and narrow hold downs are reversed
 
It could be that the rocker shaft bolt hold downs could be off, how are they supposed to go so I can verify? It's entirely possible since these got moved around.

As far as massaging the pushrods holes further, the machinist told me on some it may be a broken circle or half moon on the thin cast side of the holes. Is this an issue?

There are left and right rockers, however I checked this and they are in the correct positions I believe :

20191006_122215.jpg


This was originally a roller cam and I'd like to stay roller cam.
 
You might need lifters with a raised seat...welcome to the world of 59 degree lifter bank angles.
 
Thats the problem with 59 degree lifter bores which was a carry over from the poly motor. The newer 48 degree lifter bores have the push rod at a more agreeable angle to the lifter. You need to look at a ghost assembly view of the 318 poly motor.
 
As MO sez..... pull the heads and grind out the lower ends of the pushrod holes as needed. The pushrod angle is steeper due to the taller roller lifters. It won't hurt anything to grind the holes more even if they break out on the inside.... MO has shown you that in his pix in post #5.

As for the contact patch, moving most of the way across the valve inside to outside is normal for stamped rockers. Their contact is designed to walk across the valve tip as the valve lift increases. If they rock so far as to go over the outside edge, then maybe be concerned. If not much, try it. It may wear a little crescent in the outer edge of the rocker contact if it gets too far over.

As for the left-to-right contact patch, it is never going to be perfect for the stamped rockers. But a problem here is that you have the hold-downs wrong in pix #11. They should go small-large-small-large-small from one end to the other.
 
The one pic you have of the rocker pedestal looks like the bolt hole is nowhere near centered.
Likely, all the bolt holes are shifted in one direction, which would shift the shafts to one end.

A normal one compared to yours:

43251354-C3F4-4FB9-BB48-49EB4F9B53E8.jpeg

3D511982-6DCB-47FB-A5D6-1662A03E921B.png


Actually...... looking at it further....... I think all the machined holes in that head are shifted to one end.

Some rocker alignment shims, along with some trimming of the hold down tabs should be all that’s needed to get the rockers in better alignment with the valves.

The way those rockers sit on the valves on that set of heads has likely been that way since day one.
 
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Look at the valve cover bolt holes..... nowhere near centered in the bosses.

That head was just a poor choice for reburbishing.

For a stock type rebuild I won’t say I would have “rejected” that head, but I def would have urged you to find a better one.
If you had been looking to have any porting done..... it would have been rejected.

15BB1EA8-516F-4503-B9C8-205ABFC37F7F.png
 
Wow. It does look like all the holes are off. I’ve never seen that before.
 
He has the rocker shaft hold downs in the wrong place. The narrow ones go in the center and on the ends. Wide in the middle. That’s not how he has them. Kim
 
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Wow, that head must've been the last one before a end of shift on a Friday! I can't say I never really noticed that, and I never heard any comments from my machine shop. My other head is perfectly normal :

20191011_184917.jpg
20191011_184929.jpg


(I'll need to clean up that flash rust, I've put on some oil to prevent from getting worse)
I hope this head is okay to use. I'm kind of upset that the machine shop didn't say anything before forking the $350 to rebuild it.

But some good news, I found an issue. My rocker shaft bolt hold down spacers were complete opposite of what it should've been. I have since corrected it and here is a before and after of the contact on the stems. Before :

20191006_122152.jpg


After :

20191011_184017.jpg


I will check tomorrow on what the dry erase marker test does for a contact patch. A few more questions :

So I'm guessing these pushrod angles are normal? Will I be able to run safely, I'm not racing this engine or revving super high for long periods of time. I've never seen lifters with raised seats. I've seen stock rollers, then the crazy race rollers at $100 a pair.

I'll see about getting the heads off again and getting then ground to clear. They will need very minimal, as the stock pushrods barely, just BARELY cleared.

And thank you to everyone who has chipped in. I am super thankful for the collective knowledge this forum collects.
 
pushrod angles are normal for rollers
you are using non roller heads for a roller build so enlongate the pushrod holes
enjoy
 
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