Tear down

bigkelk9

Well-Known Member
Very true...I very much believe owning a BigDog will either teach you patience or it will have a for sale sign on it. No real middle ground.

In the end, in a sick way, I've always been happy with the lessons it teaches me.



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Yeah.. and believe it or not I am determined to figure this out.. u once told me that and made me think real hard every time Dahlia pisses on my parade!
 

Th3InfamousI

Administrator
Staff member
Yeah.. and believe it or not I am determined to figure this out.. u once told me that and made me think real hard every time Dahlia pisses on my parade!
Regarding the torque sequence for the head bolts. Did you do 8 then 18ft lbs then another 90 degrees (1/4 turn)?

Also note the mention of a drop of oil, so the torque rating is WET. There is a difference between WET and DRY ratings, if you didn't apply some type of bolt dressing then you probably came up a little short on the torque.





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bigkelk9

Well-Known Member
Regarding the torque sequence for the head bolts. Did you do 8 then 18ft lbs then another 90 degrees (1/4 turn)?

Also note the mention of a drop of oil, so the torque rating is WET. There is a difference between WET and DRY ratings, if you didn't apply some type of bolt dressing then you probably came up a little short on the torque.





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Yea sir.. sure did.. have the entire manual thanks to s&s
 

SMCT

Active Member
I don't know whats what and kind of dont care right now. Just put almost 2k into this fucking engine, followed instructions to a t. Torqued everything per manual and have an oil leak and it's leaking compression and the top rear rocker box still fuckin ticks!..
So let's here a recap on who touched what and what they and you did.
 

bigkelk9

Well-Known Member
what the heck is that circular ridge on the heads surface?
That's what he called a spin drop to loose the gap and increase the compression. So what he did was bore put my jugs because they weren't true, so he sent me the jugs and new pistons back so i can mock it up and send him back a measurement on the depth from the top of my jugs to the top of my p stons which was .032 on the rear and .037 on the front. He calculated how much to shave the heads to bring me down to about .025 - .029 on both which were specs from S&S for their crate 117's. When he sent everything back he sent me metal gaskets and told me to use those. I torqued my heads down per instructions which I still don't feel comfortable with because it just doesn't seem like it's enough. But I did and left it like that. The whole purpose for this tear down wasn't to increase the power of the bike and all That, but being I was getting brand new Carillo pistons and it was bored over and the bike was already tore apart I figures why not make it how it is supposes to be instead of dummied down for a production EPA bike which is what we all had originally.
 

SMCT

Active Member
He made that so called "drop" modification to net you a difference of about .007? That's what the math calculates out to. That's absurd. Now you have a gap, an area, or a void that is between the protruded portion of the cylinder head and the cylinder. To avoid detonation you tighten up the quench area as much as possible. That means if you effectively, and correctly measured .032 and .037, then the only area that should have material removed is the cylinders base, and no where else. That amount that needs to be removed should have been anywhere from .035 to .037 on one cylinder and .030 to .032 on the other cylinder. This method prevents detonation because it forces the air/fuel mixture to the pistons center, for the combustion process.

As far as the torque instructions on that paper posted, it's horse shit. The 90 degree method is bullshit and the least accurate. Polish the o.d. of the head bolts shoulder. Use moly on the shoulder, use moly on the threads. Torque the 4 bolts to 17 to 18 ft pounds, then to 32, and last torque at 40. Between torque intervals, let sit for around 2 minutes or so, as this settles the gasket. Pull the torque wrench slow and steady, and if you want to throw an additional step in prior to the 17 to 18 initial torque, you can do so with 10 to 12 foot pounds.

My opinion on your cylinder head machine work is, to surface the heads flat, period. Get rid of that step.
Check your manifold to port alignment and correct if necessary.

How the heck are you suppose to get rid of that tic if you didn't make adjustments to the rocker boxes?
Did you put new lifters in this engine? If not, my suggestion is to put a brand new set of S&S premium lifters in it. The only way to figure this out, is to discard the old and put on new. It's only two cylinders and not a V8. Things just don't correct themselves by wishful thinking.

P.S. I have head gaskets that are .023, .030, .035 and .040. When you think about what was done for .007 of a difference, it's crazy logic and makes no sense what so ever.
 
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bigkelk9

Well-Known Member
He made that so called "drop" modification to net you a difference of about .007? That's what the math calculates out to. That's absurd. Now you have a gap, an area, or a void that is between the protruded portion of the cylinder head and the cylinder. To avoid detonation you tighten up the quench area as much as possible. That means if you effectively, and correctly measured .032 and .037, then the only area that should have material removed is the cylinders base, and no where else. That amount that needs to be removed should have been anywhere from .035 to .037 on one cylinder and .030 to .032 on the other cylinder. This method prevents detonation because it forces the air/fuel mixture to the pistons center, for the combustion process.

As far as the torque instructions on that paper posted, it's horse shit. The 90 degree method is bullshit and the least accurate. Polish the o.d. of the head bolts shoulder. Use moly on the shoulder, use moly on the threads. Torque the 4 bolts to 17 to 18 ft pounds, then to 32, and last torque at 40. Between torque intervals, let sit for around 2 minutes or so, as this settles the gasket.

My opinion on your cylinder head machine work is, to surface the heads flat, period. Get rid of that step.
Check your manifold to port alignment and correct if necessary.

How the heck are you suppose to get rid of that tic if you didn't make adjustments to the rocker boxes?
Did you put new lifters in this engine? If not, my suggestion is to put a brand new set of S&S premium lifters in it. The only way to figure this out, is to discard the old and put on new. Things just don't correct themselves by wishful thinking.

P.S. I have head gaskets that are .023, .030, .035 and .040. When you think about what was done for .007 of a difference, it's crazy logic and makes no sense what so ever.
Okay, so I just spoke with him, he had my dry for everything first without gaskets to assure everything was good and heads would sink into place, he also just informed me that the specs I used for torque will not work with the Cometic gaskets he provided and sent me a torque sheet similar to what u stated. I have brand new lifters and push rods, cam, valves to accommodate the cam, heads have been completely redone, brand new Carillo pistons.
 

john sachs

Well-Known Member
Nothing wrong with spin dropping heads to set the quench.
If you're going to use the S&S head torque method, use 10, 20, and 90 degrees. Works well and shouldn't pull a stud. I find that S&S cases can't stand the same torque #s that the Harley Davidson Twin Cam cases can.
Noise in rear cylinder ? Diagnose the problem. If its in the rocker arm/shaft area,you can use Rocker Lockers, this way you don't weaken the rocker arm saddles by removing any material or modifying them.
You may want to call Randy at Hyperformance, and explain the problems you're having. He's stand up, and will help you.
John
 

bigkelk9

Well-Known Member
Nothing wrong with spin dropping heads to set the quench.
If you're going to use the S&S head torque method, use 10, 20, and 90 degrees. Works well and shouldn't pull a stud. I find that S&S cases can't stand the same torque #s that the Harley Davidson Twin Cam cases can.
Noise in rear cylinder ? Diagnose the problem. If its in the rocker arm/shaft area,you can use Rocker Lockers, this way you don't weaken the rocker arm saddles by removing any material or modifying them.
You may want to call Randy at Hyperformance, and explain the problems you're having. He's stand up, and will help you.
John
Randy is who did the work.. appreciated ur input and glad someone knows what the hell spin dropping is.. lol
I spoke with s&s today and they told me the same thing Randy did which was to throw some red or green locktite on the shaft for the rocker arms which is most likely causing my tick. So I'll keep you posted.
 
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Th3InfamousI

Administrator
Staff member
Nothing wrong with spin dropping heads to set the quench.
If you're going to use the S&S head torque method, use 10, 20, and 90 degrees. Works well and shouldn't pull a stud. I find that S&S cases can't stand the same torque #s that the Harley Davidson Twin Cam cases can.
Noise in rear cylinder ? Diagnose the problem. If its in the rocker arm/shaft area,you can use Rocker Lockers, this way you don't weaken the rocker arm saddles by removing any material or modifying them.
You may want to call Randy at Hyperformance, and explain the problems you're having. He's stand up, and will help you.
John
John, do you use the Cometic torque values on your builds or stick to SS? Cometic seems to represent 42ftlbs, but wondering if that is the Harley cases you mention and you stick with SS values.



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