Mystery motor rocker set up

[joshua]

If you want to skip the back story just scroll to this symbol ## for the question.

Quick back story is, I bought this engine very cheap. It was rebuilt by an unknown machine shop. Then owner of the motor passed in a motor cycle accident. Taking all the info with him. His 2 son in laws sold it to me for 500 But the caveat is there was no paper work and these guys were not hot rodders. So I’m going in blind.

When I bought it was dark. All I could see is it had Crome valve covers, a paint job and and a brand new looking edelbrock 4 barrel.


I’m in the process of building a run stand and close to the end of it. I want to break it on it. Also My bronco is a ways away before the engine goes in, and would like to run the motor once a month.

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Question is since I have no clue when this was built or put together, should I go through and make sure rockers are set probably or do I need to pull all the lifters and soak them in oil to make sure they haven’t leaked down. It is a flat tappet cam. Or can I just prime the motor and adjust the rockers after that point? Is that something I should do, or even wise to do? As I have also heard it’s better to adjust the rockers when the lifters are springy and not pumped up. I would really love to hear I can just check the adjustment as is. But I’m worried that’s not the case.


I have never broke an engine in, so I’m pretty nervous. Any help would be great. Also is this the good oil to use. Oil in picture.

Also not using those headers for break in.



Thanks for any suggestions you may leave!

 

[ared77]

Others may disagree, but based on what you were told, and how it looks I'd spin the oil pump with a drill and then fire it up!

 

[bmc69]

I see so many people mention soaking lifters and worrying about them "leaking down' when in fact you never "pre-fill" or "pre-pump" hydraulic lifters. They are specifically designed and intended to be installed "slack" and then pump themselves up to correct height as soon as the engine is turning over.

Those look like some pretty decent roller rockers!. Nice build ya got there apparently. I'd prime the oil pump and fire it up.

 

[BOBS 2 68S]

Spin the oil pump and hand turn over the crank to get oil pumped into every thing. Can you see any cam assembly lube on the cam?

 

[joshua]

Ya I figured I didn’t have to worry about them being pumped up till start up. When inspecting everything I noticed this cracked set screw. I’ve been searching. Can’t seem to find it.

 

[Bajabrewer]

I'm taking a guess that you may have these -
https://scorpionracingproducts.com/...MI3_jClrre_gIVexKzAB0MrAuTEAQYBiABEgJolPD_BwE

I remember seeing them when I was looking for 7/16 stud nuts for my 69 351 - I ended up getting the Comp Cam poly lock nuts so I have no experience with the scorpions. try to find what heads you have & what size the rocker studs are then decide if you want to run those or switch to something else. Good luck with the build - sort this out - Prime it & Fire it up!

 

[joshua]

I'm taking a guess that you may have these -
https://scorpionracingproducts.com/...MI3_jClrre_gIVexKzAB0MrAuTEAQYBiABEgJolPD_BwE

I remember seeing them when I was looking for 7/16 stud nuts for my 69 351 - I ended up getting the Comp Cam poly lock nuts so I have no experience with the scorpions. try to find what heads you have & what size the rocker studs are then decide if you want to run those or switch to something else. Good luck with the build - sort this out - Prime it & Fire it up!

Yes that is the closest looking I could find.

Thank you

 

[gclauson]

Also, if it is a flat tappet cam, you need to follow proper break-in procedures rigorously, versus a roller cam!

Sent from my SM-N970U1 using Tapatalk

 

[joshua]

Also, if it is a flat tappet cam, you need to follow proper break-in procedures rigorously, versus a roller cam!

Sent from my SM-N970U1 using Tapatalk

yes. This is what I’m most worried about.

 

[cldonley]

I'd prime it and fire it up!

 

[EPB72]

The AFR is for air flow research ..

 

[spap]

Fogging oil is always good if you don’t know th history, but looking at the motor, I would imagine the guy building it coated the cylinders pretty well.
curious what The Cam lift is

 

[DirtDonk]

The oil looks good.
Is that a hole all the way through the setscrew? Double check to make sure there are no missing set screws in the poly locks, but it’s also possible that that’s an oil restrictor screw.
I don’t remember seeing them with that cone shaped tip before, but I personally never use them anyway. It was an old school Chevy race engine trick, that probably was used on the other engines as well.
It was to restrict the amount of oil going up to the rocker arms or something if I remember, to keep the other important pieces from being starved for oil.
Just a high rpm thing though, and not needed unless you’re going racing.
The hole looks too large to be a replacement set screw for an oil gallery behind the timing gear.
A common trick was to drill a .030” diameter hole in the gallery plug so pressurized oil would spray on the back of the cam gear and chain.
Again, might be another Chevy thing. I don’t remember doing that to a Ford.

What bell housing is that? Is it a clutch type bell housing, or the front off of a C4 transmission?
Looks like aluminum, unless it’s been painted?
If it’s an aluminum clutch bellhousing, it might be for the smaller passenger car size clutches.
I could be wrong, but it might be worth checking unless you know already.
If your engine stand would be easier utilized without a bellhousing, we have a starter mounting bracket that would take the place of the bellhousing and still let your mount just the starter.

 

[DirtDonk]

By the way, how long ago did all this take place? I don’t know if you mentioned it, but did anyone have any idea how long it had been since the engine was rebuilt?
Answer to that question might help me decide whether I was going to just fire it up as everyone has suggested, or open it up and put extra assembly lube on the camshaft lobe’s again.

I don’t know how long cam assembly lube is good for, but that might be a question to ask a manufacturer.
And sometimes they use a sticky Moly lube that stays in place for a long time, while some people simply use oily assembly lube, because they are assuming the engine is going to be fired up very shortly.
If an oil type lube, I’d be very wary of firing up a flat tappet cam that’s virtually dry.
I absolutely hate pulling things apart unnecessarily. But I think it’s worse to have to pull it apart later to fix it.

 

[jamesroney]

It is a flat tappet cam. Or can I just prime the motor and adjust the rockers after that point? Is that something I should do, or even wise to do? As I have also heard it’s better to adjust the rockers when the lifters are springy and not pumped up. I would really love to hear I can just check the adjustment as is. But I’m worried that’s not the case.

Thanks for any suggestions you may leave!

1. It is a flat tappet cam.

Just stop there. I will interpret and translate what you just posted. Then you can answer the question yourself:

"I just bought an engine that was rebuilt improperly, and will never run correctly. I have no idea what cam is in it. I have no idea what pistons are in it, and I don't know anything about it. I really just want to put an unknown pile of crap into my Bronco restoration project so that I can say I got a good deal. After I install the engine, and it won't create vacuum, and it won't make horsepower, and it overheats, I really want to spend a fortune on tune up parts so that I can still never get it to run right. But maybe I will be lucky, and the guy that built it spent at least $1500 on aluminum heads, but didn't put a huge cam in it. Or maybe he did. And I don't even know the firing order of this cam. But maybe it's a 351W cam and I will get lucky. And maybe the valve springs are right for this cam. And maybe it won't go flat in the first year I own it. But it's OK, because I don't know the compression ratio, cam timing, lift, duration, or performance expectation. So I'll spend my time now worrying about how to adjust the valves."

I'm telling you that it was rebuilt "improperly" because the builder had no idea of your intended use. So it cannot possible be correct for you. Since it is going into a Bronco, and since we are past the Reagan Administration...that engine needs to have a roller cam. This is a FACT. Not just an opinion, not conjecture. Only a fool would run a flat tappet cam in a Small Block Ford in Bronco unless they had to. And if that thing has a Comp Cams hydraulic flat tappet cam built before 2018...get rid of it NOW.

Save yourself a ton of heartache. Pull the intake, and shit-can that camshaft. Take a camera with a bore scope and and look down the spark plug hole to see if you can identify the pistons. Try to get a picture of the piston part number and the overbore. You need to know if it is flat top, or relieved, or dished, or raised. If it more than .030 overbore...then stop. Otherwise, just pull a head. If you don't know what you have, then you can never know what will work.

You have a lot of really nice parts on the top end. Don't shoot yourself in the foot. Now is the time to learn what you bought.

 

[jamesroney]

but it’s also possible that that’s an oil restrictor screw.
I don’t remember seeing them with that cone shaped tip before, but I personally never use them anyway. It was an old school Chevy race engine trick, that probably was used on the other engines as well.

Hey Paul, @joshua is working on the top end. That set screw is used by the aftermarket roller lifter manufacturer as a jamb screw on the rocker nut. They have to have that dog point otherwise they will mash the top of the rocker stud when you lock them down and mess up the threads. I think he just noticed that one was cracked. I'm pretty sure that he has 16 of them.

A single 3/8 UNF dog point set screw is pretty hard to come by. McMaster - Carr is your friend. Otherwise, just get a regular set screw, and put a taper on it.

You want to change them all. You will find that they are Chinese Junk, and have been heat treated to above Rc-60. The start as grade 8, but after heat treat, they can get quite brittle. you should be able to get a full set from Summit. It is not a super critical function, and they won't fall off. But they will round out, and then they are really hard to remove "in frame."

 

[DirtDonk]

Sorry for the potentially off-topic sideways segue, but what was wrong with the pre-2018 comp cams? And what was done to fix it?

 

[jamesroney]

Sorry for the potentially off-topic sideways segue, but what was wrong with the pre-2018 comp cams? And what was done to fix it?

HA!!!! There is a little known "problem" with the comp cams metallurgy. It isn't actually a Comp Cams problem. It is a combination of the ZDDP plus high spring pressures, plus high lobe rates that exposed the "problem."

Comp will tell you that there is nothing wrong, and has never been...and they didn't change anything. BUT...there was and is a well reported issue with comp cams wiping lobes on low mileage, otherwise moderate lift cams.

The cam metallurgy, lobe profile, valve spring pressure, lubrication oil, and break in procedure, are ALL to blame. It is the combination of all of these things that "cause" the failure. BUT it turns out that you can mitigate the failure by addressing any one of the culprits.

All of the engineers at all of the vendors (and you KNOW who they are...) basically sit in a circular firing squad and lob shots at each other. But at the end of the day, it is a combination of factors that are the "root cause." UNFORTUNATELY for Comp Cams, many other cam manufacturers were not sitting on the edge of the metallurgy design window, so they were much less impacted. But when you dance near the edge of the cliff, you are the first to fall off. Everybody was impacted in some way, and you can argue that it was "because of" the change in ZDDP by the API. But the timing, and the nature of the distribution of failures clearly indicate that it was a combination of factors. (metallurgy x profile x springs x lubrication x break in)

The legend is that Comp made an "improvement" to their cams in about 2018. I can only look at the data that I have. (Being a Six Sigma Black Belt is a curse...) I don't want to get in trouble for blaming Comp Cams. There's plenty of blame to go around. But when Comp tells me to remove half of the valve springs on break in, and Edelbrock says to use break in compound on the Cam, and Melling says "huh?" and the API says "there's plenty of Zinc" and the mechanic says "I've been building engines for decades..."

I can't afford to argue with engineers that are smarter than me. So I just run roller lifters like every other manufacturer on the planet. (Except Cummins in the 6BT)

 

[joshua]

Hey Paul, @joshua is working on the top end. That set screw is used by the aftermarket roller lifter manufacturer as a jamb screw on the rocker nut. They have to have that dog point otherwise they will mash the top of the rocker stud when you lock them down and mess up the threads. I think he just noticed that one was cracked. I'm pretty sure that he has 16 of them.

A single 3/8 UNF dog point set screw is pretty hard to come by. McMaster - Carr is your friend. Otherwise, just get a regular set screw, and put a taper on it.

You want to change them all. You will find that they are Chinese Junk, and have been heat treated to above Rc-60. The start as grade 8, but after heat treat, they can get quite brittle. you should be able to get a full set from Summit. It is not a super critical function, and they won't fall off. But they will round out, and then they are really hard to remove "in frame."

The machine shop built it not the guy. Allegedly And I do know the firing order. It’s the non ho. I did stick a camera in the bore. They are stock looking pistons. I believe these are cheap Chinese eBay heads. No branding. I looked everywhere. Could not find them. I only bought this engine to move my bronco under it’s own power. Not the final motor.

I built the engine run stand to see if It will even be a viable engine for the short term. I’m not going to freak out if it doesn’t go well. While 500 bucks isn’t nothing, it’s not everything. I really appreciate what you said. And it makes a lot of sense. I will take it under advisement. I just really don’t think this is a hopped up motor.

I’m guessing the reason the guy pulled out was because of a head issue. And the guy just figured to have it over hauled. Probably had a cracked head so he found the eBay special and had his machine throw them on.

I’m currently on the hunt for a 351 roller for the final product. Just trying to see if I can get this broken in for maybe a season or 2

 

[joshua]

I I found a cup point set screw. Not exactly the same but close. See pic. Also the bell is from a bronco. It is aluminum and Manual. I went through and did the quarter turn method of adjusting rockers. Hopefully it works.