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My head is twisted!

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  #31  
Old 07-18-2017, 02:15 AM
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Originally Posted by TwiZted Biker
Are you 100% sure they are a matched set of heads from the same displacement engine?
Good question. Seems a lot of obvious things going wrong with this setup,
 
  #32  
Old 07-19-2017, 11:07 AM
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The heads were off the same engine as it was a customer of my friend who owns the shop.
I was using brake cleaner and O2 sensor and gauge. You could just watch the gauge go rich when sprayed but it was difficult to find the exact spot it was leaking as it seemed to move around. There was no air cleaner on the carb and the backing plate kept any mist from getting to the intake of the carb.

So yesterday I took the mated heads and set them up on a rotary table on the mill. I put 3/8" dowel pins in the pin holes on the rocker surface. I was assuming these were 90 degrees from the dowels on the head gasket surface. I put a parallel across the pins and indicated the pins to 0. I then rotated the table 20 degrees. I put a level on the two intake surfaces and they were different angles but neither were at 20 degrees. I rotated the table till the front head was level and it had moved 1 degree 5 minutes. At this point I quit.
Tomorrow I will double check that my mill is level, which it was at one time.
I'm taking the set up down and double checking that the two sets of dowel holes are indeed 90 degrees apart.
I'm hoping that my set up is correct but if it is then are the surfaces that far off or is the 20 degree dimension off.
I will take a spare head that I know is good, just not ported, and use the rotary table and dowel pins and use an indicator to figure the angle just in case Harley didn't use an even number, which is rare in my experience, but how does that go? Measure twice cut once!
 
  #33  
Old 07-19-2017, 11:30 AM
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Next time you test it, replace the MAP sensor if you haven't already.
 
  #34  
Old 07-19-2017, 11:40 AM
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You mentioned that HD uses even numbers on angles.. What angles are even numbers? IIRC the exhaust valve is at 31 degrees on stock TC and evo heads.. Cylinder angle is at 45..
 
  #35  
Old 07-20-2017, 01:59 PM
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MAP sensor was tested with mity vac. I didn't say angles but numbers. I built a fixture for holding the cam plate and the distance between the two bearing centers and the distance from their centerline to the center of the crank bushing was all fractional numbers. Nice and easy! I was hoping the angles would be the same! I had bought an aftermarket cam plate that was advertised just for gear drive cams. My cams rattled badly. I took it out and compared it to the stock plate and the bearings were too far apart. I had minor wear on the stock cam plate from the oil pump so I lapped it smooth and flat but still needed to change out the bushing. I pressed it out not knowing that it was knurled on one side and grooved the bore of the plate! So I made the fixture and bored the plate. Made my own bushing and shrunk fit it then bored it to size. Installed and you can't tell it has gear cams it's so quiet.

I hope to be back in the shop tomorrow to finish the heads.
 
  #36  
Old 07-20-2017, 02:14 PM
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do the symptoms seem to come and go or is it good for an while and once it craps out, it's pretty much crapped out..
 
  #37  
Old 07-20-2017, 02:18 PM
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Originally Posted by tootal
MAP sensor was tested with mity vac. I didn't say angles but numbers. I built a fixture for holding the cam plate and the distance between the two bearing centers and the distance from their centerline to the center of the crank bushing was all fractional numbers. Nice and easy! I was hoping the angles would be the same! I had bought an aftermarket cam plate that was advertised just for gear drive cams. My cams rattled badly. I took it out and compared it to the stock plate and the bearings were too far apart. I had minor wear on the stock cam plate from the oil pump so I lapped it smooth and flat but still needed to change out the bushing. I pressed it out not knowing that it was knurled on one side and grooved the bore of the plate! So I made the fixture and bored the plate. Made my own bushing and shrunk fit it then bored it to size. Installed and you can't tell it has gear cams it's so quiet.

I hope to be back in the shop tomorrow to finish the heads.
I've replaced bushing the same way but simply mount the cam plate to the face plate. Zero the hole, bore the bushing enough to peel out then install new and bore to size.
 
  #38  
Old 07-22-2017, 01:52 PM
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I took my unmolested spare front head and put in all the dowels. I put the head gasket surface on the mill table with the dowels against the side of the table. I put a parallel across the dowels on the other side of the head and indicated the parallel and it is indeed 90 degrees to the others, so that assumption was correct.

I put this head on the rotary table head gasket side down. I set the table up vertical and indicated the parallel again, across the rocker side, to zero. I rotated the head 20 degrees and checked level and it wasn't level so I rotated it back and at level it was 1 degree 5 minutes less than 20 degrees. At this point I put the indicator in the spindle and got it within .001" across the intake surface. The final angle reading is 18 degrees and 56 minutes. So much for even numbers! It would be interesting to actually know the factory spec. and what the tolerances are! Any company that thinks it's ok to have a crank run with over .010" runnout probably doesn't care too much about intake angles either!

I had to quit at that point. On Monday I will set both heads up together and skim cut them at that angle so they will be a matched set. I will also indicate and possibly skim cut the air cleaner mounting points to make sure they are parallel also.


As far as the symptoms go, I couldn't get it to seal at all except for one time. I had installed the blue silicone James seals and then had to stop. I came back the next day and fired the bike up and it idled perfectly. After it warmed up I was able take the choke all the way off and set the idle mixture screw at 2 turns out with a a/f ratio of 13.5. It was music to my ears but one problem, I hadn't hooked up the cables due to time. I shut it off and after it cooled I pulled the carb back out carefully and hooked up the cables and gently put it back in but it was no good. No matter what I did after that I couldn't get it to seal. I've been through all the different seals and methods, even the one in the book, yet nothing will seal. That's when I figured there had to something seriously wrong.
 
  #39  
Old 07-29-2017, 11:14 AM
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I mounted the "head bundle" onto the rotary table and then moved it horizontal and indicated my parallel across the dowel pins. I rotated it 18 degrees 56 minutes and checked the intake surfaces with a level. One head had the bubble touching the line in one direction and the other head was touching the line in the opposite direction so they are clearly not matched. It took .025" to clean them up. I rotated the table back to zero and took a skim cut on the breather ports just to be sure they were the same. I reassembled the engine and set the intake on there the the ports line up perfect and the manifold doesn't rock like it used to. I've got to go get some gas and fire it up and see what I have. Cross your fingers...
 
  #40  
Old 07-29-2017, 12:05 PM
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So the problem was not enough clearance between the manifold and the heads? Not allowing it to fit in place? IIRC heads are 3.75 inches tall. You can tell if they've been milled if the number is different..
 


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