Shovelhead Diagnosis

[Sportycoat1100]

Alright fellas, I’m going to need a lot of help on this one. I’ve been struggling with this engine for a while and I’m trying to nail down what might be happening before I decide how to move forward.

Bear with me on this one, Details:
It’s a 1975 74ci cone shovel. When I bought it I was told that it had the “evo oiling kit” installed with shimmed evo rocker arms and not the roller rockers. So far I know it has an EV27 cam, one s&s tappet block, one Harley evo tappet block, s&s quickie pushrods & hydraulic evo lifters. S&S super E, points ign

What I have done:
I had new rings installed because the olds were shot. I rode it a few miles but it was smoking so, full top end rebuild. I also had to make some changes in the build along the way so I installed a S&S oil pump.
After it came back from the rebuild it started right up no problems. After a the heat cycles I took it for the break in mile and it was running like shit. It would bog when rolling on the throttle and seemed to be carb issues. I replaced it with a carb that I know was dialed in, same issues. After trying to dial it in the plugs began to foul. Now anytime I put new plugs in it will start up fine, idle great, but when I put it in gear the plugs will immediately foul within 5 mins and stall out. Also forgot to mention that it’s spitting fuel through the carb pretty decently as well

My plans:
I’ve talked with multiple people and we have walked through this engine multiple times with their responses the same “that’s odd, it should run fine.” I’m leaning towards pulling the evo crap out and replace all the stock shovel parts and go from there. I will try to upload a link to a few YouTube videos for further diagnosis

[Sportycoat1100]

https://youtube.com/shorts/hzwB4VQwVUk?feature=share

https://youtube.com/shorts/iqgzAnzc2tg?feature=share

[JBinNC]

Where to begin?

Nothing wrong with converting a shovel to an evo valve train, but there are pitfalls. If anything is missed, you will have a troublesome piece of junk.

One S&S tappet block and one H-D tappet block? Was this motor built out of leftover junk? Might give a clue as to the care with which it was built.

Evo rocker arms cannot be "shimmed" to fit into shovel rocker boxes. Either the rocker arm must be narrowed, or a stepped spacer made/used on the left side of the shaft to accommodate and position the rocker arm. You may also have to cut clearance on the inside of the rocker box.

Even a mild EV-27 cam will provide ~.500 lift when used with evo rocker arms, and that much lift requires careful head set-up for a shovel. That means more valve and spring travel must be provided, and valve-to-valve and maybe valve-to-piston must be checked. This is THE most fucked up thing I see in shovels (and pans) because it takes time and usually some machining to get it right, and most people just won't or can't do it.

Your picture of the cam chest shows the original '75 pinion and breather gears. The cam gear would also have to be the early type for this to run properly. And the cam gear in the picture appears to have a groove on its face, identifying it as a late style cam gear. (I could be mistaken about that.)

As far as the tuning goes, is the advance unit in good condition and properly lubed? Is the timing set correctly, and are you SURE about that?

Two carbs tried with the same results might indicate that the carb is not the problem. But I hate that sort of parts substitution as a tuning method. FYI, for a Super E on a 74cu.in. shovel, the intermediate jet should be 28, 29.5, or 31 and the main jet should be 66, 68, 70, or maybe 72. Anything in this range will produce a running motor if the carb is in good condition. Tuning for the individual combo will refine these choices. And as always, the float level MUST be correct.

How are the tappets adjusted, and do they have the S&S tappet limiters installed? Two questions you MUST know the answers to.

I actually think you have a can o' worms here that may have been poorly assembled by people who did not really understand how the evo conversion is done. But it could be that the tune-up is just off, and you just need to use some patience to get it dialed in. I hope it is the latter.

Good luck with it,
Jim

[Sportycoat1100]

I’ll try to answer these to the best of my knowledge. First off, yes this engine was 100% thrown together with whatever parts it could be. At this point it is beyond a can o worms!

As far as the rockers, I can’t confirm anything. That is going off of hearsay. Also with the valves they appeared to be newer as well but was not told of any headwork like you’re talking about.

With tuning I am sure everything with the advance unit is new/good. And I am sure that it is set as it should be.

With the carbs I took my main s&s that was dialed in and tried all the various jets setups with the same issue.

I’m unsure about the tappet limiters. If they are the same as tappet cuffs then no, there are not any. All that I have is basically an evo tappet block/tappet kit and adjust the pushrods 24 flats and wait 30-40 mins until and check the roll with my fingers.

I’ve spent the better half of 3 months working with this engine and trying to work out the kinks unfortunately

[JBinNC]

Since you are in Myrtle Beach, according to your profile, you are welcomed to bring the motor up here, and I will sort it out. Won't be cheap, but you will have a running motor that you can use. Limited time offer, because I am going to severely limit the amount of new work that I am willing to take on, starting at the end of September.

Jim

[Sportycoat1100]

I saw that you were in high point so I was going to see if that was a possibility. My current plan was to replace all the stock parts (rockers, tappets/blocks, pushrods, J cam) and at least give that a try. So far I’m looking at $530

[JBinNC]

I saw that you were in high point so I was going to see if that was a possibility. My current plan was to replace all the stock parts (rockers, tappets/blocks, pushrods, J cam) and at least give that a try. So far I’m looking at $530

That might be the simplest approach, and that combo of parts is a known for a 74cu.in. shovel, so it should produce a reliable motor.

Jim

[confab]

it had the “evo oiling kit” installed with... evo rocker arms and not the roller rockers. So far I know it has an EV27 cam... Harley evo tappet block, s&s quickie pushrods & hydraulic evo lifters. S&S super E..

That's my exact setup.. And it runs great. I couldn't be happier with it.

That's not your problem. Although, as JB says, the install may be an issue.

You can't just run stock EVO rockers, as is. (I machined mine down to fit, and then ground them and the boxes .060 clearance, all round!) There's no room for this setup with stock parts. Everything has to be clearanced, bigly. S&S heads and valve springs in stock form will clear with no mods. Because I checked everything when I was doing it. The heads were the one thing that didn't need work. But (literally) everything else did. I doubt stock heads will clear without modification.

Also forgot to mention that it’s spitting fuel through the carb pretty decently as well

Did you change the exhaust? Because mine did that and there was a thread on it trying to diagnose it. I tried EVERYTHING and the people here thought of EVERYTHING and none of it helped. Initial startup, so you're just at a total loss and wonder what went wrong?

It was the mufflers.. LOL!! Crazy, right?

I bought some cheap mufflers and they had rusted inside, and it would idle around just fine and when I'd gas it, it would literally blow fuel out of the carb and onto my leg.

Also.. Is your float stuck? Have you checked it?

[Sportycoat1100]

This is why I think this engine was sold on a stack of lies. And I’m also convinced now that it is not a EV27 cam or evo rockers made to fit. My heads definitely stock.

And I did change my exhaust but it’s brand new with cocktail shakers. I also forgot to mention that it blows oil from the tail pipes. Not always in the form of smoke but they do have a coat of oil on the inside

And I’m sure that the float is correct. When I was working with the different size jets that was my first go to, to check the float

[confab]

Some guys do this swap with the shovel rockers, and leave the oil lines intact and block oil up the lifter. I wanted the EVO oiling, so mine has no lines and oils up the push rods like a car.

An EV27 will be marked, I think? I'm sure mine is.. It says it right on the cam, I'm almost positive. I haven't seen it for three seasons now, but I'm sure it was.

My mufflers were new, also. Just super restrictive and made worse by the rusted, fine perf, baffles. I pulled the mufflers off and that fixed it. LOL.. I went nuts trying to find the problem. Adjusting valves and timing and everything else.

Oil makes me wonder if the rings are installed right, or maybe they're not seated? It easy to bend them and mess them up. Your builder didn't didn't restrict the oil returns, I guess?

I use the S&S Pump also. It's the STD volume one. It's perfect. No issues from that.

[confab]

Oh.. And I had a cylinder I had to mod because the oil return hole was at the level of the oil ring and would load it. It was an aftermarket one and they say that's not normally a problem. But it was on my bike. If you changed the cylinders? I guess that's a possibility for your smoke. Although, probably a slim one.

Dragstews had a stroker engine stunt with a reamer and a bullet casing that let me move it down and out of the way.

[Sportycoat1100]

So JB hit the nail on the head I just didn’t catch it. He mentioned the pinion & breather gears were still stock. I only realized what he meant when I was shopping for the J cam. In the notes it states that the pitch on the gears are different on 77- up. Mine being a 75 that’s why she was running like shit…the more you know. I’m still converting this engine back to stock but from now on kids, check your pitches