V-Twin "Replica" Pan Heads

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awander
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Re: V-Twin "Replica" Pan Heads

#61

Post by awander »

I took a break from work, and installed the valves in the rear head, with some very weak test springs.

I installed the head without a head gasket, and tentatively turned the motor over, and there was no contact between the valves.

I'll have to get out the borescope to confirm how much clearance there is between them when they are closest together.

I'll also have to check the front head.
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Re: V-Twin "Replica" Pan Heads

#62

Post by Raytag »

ghostrider wrote: Fri Oct 23, 2020 4:11 pm Yes, the back cut on the valve is just like the diagram you posted. I sunk the valves a little, but didn't want to sink too much so I did the backcut too. The cam that I was setting these up for has TDC lifts of about .200 and .180.
:shock:

These numbers includes the .060 safety already ? Top retainer to seal safety in order to prevent coil bind right?
Besides Kibblewhite 20-20455 + 20-20430 for a .415 lift cam they offer 2 kits for a .600 cam (20-20100 + 20-20445) but with a higher spring pressure

After re-reading your posts and recalculating your numbers I am somewhat shell shocked to see that these heads do not provide enough room for an Andrews-A.
So as Ghost and Roo are suggesting, beveling the valve diameter and/or grinding the valve spring seats with a spring seat cutter seem to be the only option
Damn.
awander wrote: Fri Oct 23, 2020 1:58 pm ..
Does anyone have the figures for valve lift at overlap/TDC for the stock H cam?
Unfortunately nightrider.com provides everything except those numbers you need
S&S claims these numbers (but they do partially differ from nightrider.com):
So almost .060 between the valves ( .131 minus .076 )
Valvelift Front: .389 --- Lift IN@TDC: .076 ---Lift EX@TDC: .131
Valvelift Rear: .391 --- Lift IN@TDC: .076 ---Lift EX@TDC: .131

Ray
awander
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Re: V-Twin "Replica" Pan Heads

#63

Post by awander »

I found out some more info. The valves in the front head definitely touch each other during the overlap.

The valves in the rear head do not.

I wasn't able to see too much with the borescope/endoscope camera-it's hard to get it positioned correctly, through the spark plug hole.

I think if I cut the overall diameter of the valves slightly, leaving 0.020 from the edge to the actual seating location, and then do a "back cut" as ghostrider suggested(it's really a Front cut, though, isn't it?), I'll be able to get .060 clearance between the valves at their closest position.

They'll end up looking like this:
valves.JPG
valves.JPG (49.44 KiB) Viewed 1099 times
I'm just a little worried about the final widths of the margins, as dimensioned in that drawing.

The Intake is on the left, Exhaust on the right. The dark band is the actual seating area.

Any opinions on this profile?
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Re: V-Twin "Replica" Pan Heads

#64

Post by Andygears »

A rolled up piece of plumbers putty laid across the piston top, then reassemble head, roll over motor and measure clearances in the squashed putty. Might help.

Andygears
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Re: V-Twin "Replica" Pan Heads

#65

Post by RooDog »

A rolled up piece of plumbers putty laid across the piston top, then reassemble head, roll over motor and measure clearances in the squashed putty. Might help.


That's a necessary step in setting up a performance valve job for piston to valve clearance, but does not address how close the valves come to one another during overlap. That must be visually checked at TDC, or with a bent wire, like a paper clip, as a feeler gauge between the valves. We should be looking for about.060 here.....
A Trock tool makes bench testing possible and easy.....

Image
....RooDog....
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Re: V-Twin "Replica" Pan Heads

#66

Post by awander »

Today I ground the valves from the front head (the worst one) to the approximate dimensions shown in the post above, but I made sure to leave at least .020 between the valve seating ring and the edge of the margin, and I left .035 width margin on the Intake valve, and '.075 width margin on the Exhaust valve.

I assembled the head to the engine, and while the valves no longer touch when it is turned over, the clearance between them is only about .020.

I'm thinking I will need to sink the seats a bit as well.

Also, I fitted the valve covers(with no gaskets), and I noticed that the pushrod end of the rocker hits the valve cover, so sinking the valves a bit should help with that as well.

The valve collars are a good way away from the sides of the valve covers, so I'm not concerned about clearance there, just on top.

Is it possible to get the equipment to cut these seats a little deeper myself, without spending a small fortune? The seats are magnetic, and silver in color, so I assume they are steel.
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Re: V-Twin "Replica" Pan Heads

#67

Post by RooDog »

Neway Valve Seat Cutter Kit
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Re: V-Twin "Replica" Pan Heads

#68

Post by northeastconfederate »

RooDog wrote: Sun Oct 25, 2020 8:15 pm Neway Valve Seat Cutter Kit
I've used this kit numerous times in the past and it definitely works. Used the Neway on Benz valve jobs when I was a Benz tech. If you can find a Sioux seat grinder set used, that makes for a much nicer way to do it. I was able to borrow a Sioux seat grinder when I built my Ironhead stroker years ago.
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Re: V-Twin "Replica" Pan Heads

#69

Post by awander »

Either option is pretty expensive.

Anyone have a set they want to lend (or sell) me?
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Re: V-Twin "Replica" Pan Heads

#70

Post by awander »

I found a Neway set for H-Ds on ebay for around half of list price.

Wish me luck...
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Re: V-Twin "Replica" Pan Heads

#71

Post by RooDog »

The groove in the valve for the keeper must be wider than the keeper simply so that they may be assembled & disassembled without complications. Once installed the upper surface of the groove and the land on the keeper are locked together, anything below that contact area is just along for the ride....
You test assembly was true, and correct. I would get a set of Manly or Andrews springs, and blow off the Rusty Tedd's springs.

If the clearance between the installed seals and the bottom of the upper retainer is sufficient for the valve lift, + .060, there is no need to remove the seal. However if there is not that amount of clearance, the two will clash the first time the engine is rotated. This can be remedied buy removing the seal and chopping some material from the top of the guide. I use a die grinder, deburr the hole and outer edge and reinstall the seal. You may also need to trim a bit off of the bottom of the seal, but none of this is "rocket surgery", you are just looking for enough room for everything to move freely.

BTW: Just what exactly is your end game here? A Racer, hot rod street bar hopper, or just a all around fun ride. How many cubic inches?
....RoDpg....
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Re: V-Twin "Replica" Pan Heads

#72

Post by awander »

Hi Roo:

When I bought this bike 22 years ago, it had been modified with an S&S 80" set of flywheels, and the Andrews "A" Cam.

I use the bike for daily transportation if the weather isn't too bad, and I don't have to carry too many groceries.

Thanks for the other details, I don't have any issues with the guides or the seals; at this point it just seems that the valves are not quite deep enough into the heads/seats.
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Re: V-Twin "Replica" Pan Heads

#73

Post by RooDog »

Sounds like you've got it under control.

In the late 1970s, I also built an $&$ 80", 4 1/4", bottom end, boy, I thought I was gonna be King Shit with my BIG 80 inch stroker. And then, to my chagrin, the MoCo introduces their "80" models at 81.6 inches. But my chopper would still run with what ever the Factory sold for street use, so I was OK with that. Shortly thereafter $&$ came up with the Sidewinder, 3 5/8 big bore kit, making just shy of 88 inches, now that was cool, very cool.....
Best Wishes.....RooDog....
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Re: V-Twin "Replica" Pan Heads

#74

Post by awander »

BTW, the reasons I replaced the heads:

-Back in 2009, I dropped the rear exhaust valve seat(It was a pressed-in, steel seat). In order to get running again, I borrowed a head from my '64 FLH, which was not being used at the time. That head, with a jury-rigged external oil line, has been on the '52 for the past 11 years, and I now want to put the '64 back together so I can sell it (the '64).

-I had a problem with the screw-in O-ring adapter on the original front head on the '52, and I was not sure of the seal, even after attacking it with Seal-Lock Fluid Weld.

Used original heads that I saw on ebay were pretty much the same cost as the new ones from V-Twin, with no guarantee of condition, so I decided to take a chance on the new ones.
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Re: V-Twin "Replica" Pan Heads

#75

Post by awander »

I got the Neway kit, and I've been working on sinking the valves in a bit more deeply, so they won't hit each other.

I got a good amount of exercise, and sunk the valves as follows:

RE: -.032

RI: -.023

FI: -.035

FE: -.050

Now the valves have more than .060 clearance from each other when they are both open and passing each other.

I've been slowly putting things together. Since I had the engine in pieces, I decided to replace all of the the "bling" fasteners, chrome acorn stuff, with stock type hardware.

One problem i found is that even with the heads and cylinders rotated as far toward each other as possible, the gap between the o-ring flanges on the heads is a bit wider than I think is good. I wasn't able to get a good seal no matter how much I fooled around with the manifold or the clamps. I'm looking for some thicker o-rings that I think will solve this issue.

Hopefully, I'll get the bike back together while this warm weather lasts.
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