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Has anyone done this modification? I'd like to fit evo heads to my -54 panhead. Don't ask me why...
 

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jamba said:
Has anyone done this modification? I'd like to fit evo heads to my -54 panhead. Don't ask me why...
Sorry, but when you ask a question like this, the ONLY responce is WHY?

No, they won't bolt on. You would have to do the complete top end. It could be done but WHY ?
 

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springer- said:
Sorry, but when you ask a question like this, the ONLY responce is WHY?

No, they won't bolt on. You would have to do the complete top end. It could be done but WHY ?
Well... I know they won't bolt on and that it's not easy. But.. the reason why is simply that it's been on my mind so long time. I've had panheads since -86, also few evos on panhead rigid frame, so if it can be done, i'd like to do it. Panhead is a beautiful engine but evo heads have better breathing and so on.. + exhaust pipes won'd drop...
 

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OK, then here is my suggestion. Don't do the conversion to a set of old stock panhead cases. STD makes a set of aftermarket cases that do what you are looking for. They also offer lots of benifits such as an alternator left side case, stronger castings and you can get them ready to accept the EVO top end. This also allows the use of a later style primary or belt drive kit with a starter. And allows the use of a 5 speed tranny with relative ease.

IMO, the EVO top end is to strong for the rest of the stock components used in/on panheads.
 

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springer- said:
OK, then here is my suggestion. Don't do the conversion to a set of old stock panhead cases. STD makes a set of aftermarket cases that do what you are looking for. They also offer lots of benifits such as an alternator left side case, stronger castings and you can get them ready to accept the EVO top end. This also allows the use of a later style primary or belt drive kit with a starter. And allows the use of a 5 speed tranny with relative ease.

IMO, the EVO top end is to strong for the rest of the stock components used in/on panheads.
Right, the Evo cylinders would certainly overpower a stock panhead lower end.

I also don't think it would fit in a Panhead or Shovelhead frame with the Evo cylinders, except maybe an FXR or FXLT.......I'd probably just forget about it and have a budweiser.
 

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jamba said:
Panhead is a beautiful engine but evo heads have better breathing and so on.. + exhaust pipes won'd drop...

Actually, mildly ported Shovel heads will flow just as well as stock Evo heads. The main difference there would be the practical amount of squeeze you could get with the big hemi chambers in the shovel. None of this will matter much anyway if you are still running the heavy pan flywheels, what I'm saying is, with those heavy wheels it's going to feel like a Pan no matter what you put on top. I like heavy wheels myself (more stored flywheel energy for that torquey feel) You know how these new big twin motors with the light wheels feel like a Sportster now? Anyway, Shovel heads on a Pan bottom are just plain bad...classic too.
 

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Discussion Starter · #9 ·
KKRider said:
Actually, mildly ported Shovel heads will flow just as well as stock Evo heads. The main difference there would be the practical amount of squeeze you could get with the big hemi chambers in the shovel. None of this will matter much anyway if you are still running the heavy pan flywheels, what I'm saying is, with those heavy wheels it's going to feel like a Pan no matter what you put on top. I like heavy wheels myself (more stored flywheel energy for that torquey feel) You know how these new big twin motors with the light wheels feel like a Sportster now? Anyway, Shovel heads on a Pan bottom are just plain bad...classic too.
I feel pretty much same way. Shovel heads to Pan has been on my mind too. And yes i would use pan flywheels.
 

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The sad little known truth, the 66 shovel lost 5hp compared to the 63 to 65 pan.
The reason is, the shovels shorter port and big valve lost port velocity resulting in poor fuel mix. That is why shovels will tend to ping.
On the otherhand, the panheads further back port and longer standoff manifold would swirl the fuel better.
But the old panhead is certainly not perfect.
On the shovelhead flow, it would take building up the bottom of the port to force the mix to the roof of the port to get decent flow#s, that is somthing not done much any more.
 

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Discussion Starter · #11 ·
L.Linkert said:
The sad little known truth, the 66 shovel lost 5hp compared to the 63 to 65 pan.
The reason is, the shovels shorter port and big valve lost port velocity resulting in poor fuel mix. That is why shovels will tend to ping.
On the otherhand, the panheads further back port and longer standoff manifold would swirl the fuel better.
But the old panhead is certainly not perfect.
On the shovelhead flow, it would take building up the bottom of the port to force the mix to the roof of the port to get decent flow#s, that is somthing not done much any more.
Thanks! That was something I didn't know, a useful tip!
 

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L.Linkert said:
The sad little known truth, the 66 shovel lost 5hp compared to the 63 to 65 pan.
The reason is, the shovels shorter port and big valve lost port velocity resulting in poor fuel mix. That is why shovels will tend to ping.
On the otherhand, the panheads further back port and longer standoff manifold would swirl the fuel better.
But the old panhead is certainly not perfect.
On the shovelhead flow, it would take building up the bottom of the port to force the mix to the roof of the port to get decent flow#s, that is somthing not done much any more.
My Shovelhead won't ping at all. Probably since it has 7.5:1 compression. I always understood that the reason that some of them ping is that the owners raise the compression. The hemispherical combustion chamber with the sparkplug on one side, a configuration shared with all OHV HD engines from 1936 through 1983/4 is likely the main reason for any pinging, if some is going on. It's far from ideal for higher compression. Yes, I know Dodge has a hemi but they put the plugs in the middle and they are using liquid cooling with fuel injection and a computer-controlled ignition system.

As far as the intake ports, the ones on the Shovelhead are much better than the earlier ones, IMHO. They don't have that right angle turn that was used on the 1936 through 1964 bikes. If I were designing an intake port, I certainly wouldn't put a right angle in it, would you?

The service manual on the Shovelhead rates it at 65 horsepower. I don't know how that compares with the panhead. I never ran any tests on my panhead (1950) but it certainly wasn't very fast, as I recall.

:sofa: %[email protected]
 

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L.Linkert said:
The sad little known truth, the 66 shovel lost 5hp compared to the 63 to 65 pan.
The reason is, the shovels shorter port and big valve lost port velocity resulting in poor fuel mix. That is why shovels will tend to ping.
On the other hand, the panheads further back port and longer standoff manifold would swirl the fuel better.
But the old panhead is certainly not perfect.
On the shovelhead flow, it would take building up the bottom of the port to force the mix to the roof of the port to get decent flow#s, that is somthing not done much any more.
I think both S&S and S.T.D. are selling Shovel heads with revised (improved ports) and pan heads that take a Shovel type Y manifold, thus eliminating all the turns in a stock Pan head intake tract. There are what, two 180 degree turns between the carb and intake valve on a Pan where fuel will will loose suspension and puddle? (with droplets to big to burn)

As far as published HP figures go, I don't have first had knowledge of it and if it is indeed fact, the only rational explanation for it would be how the motors were rated, Pan at the sprocket shaft...Shovel at the rear wheel, etc. There is no way the Pan put out more power than a Shovel. I called and had a long discussion with Jerry Branch regarding what you could do with a Pan versus a Shovel after reading a Pan porting article he wrote for Hot Bike magazine back in the late 70s (I think) maybe early 80s. Most Shovels only need a port clean up and the ridges blended in the bowl along with a five angle performance valve job to really sing.

I liked the days before there were dynos on every street corner and 1/4 times did the talking. It was very common to see a stock 74" super glide with maybe just jetting and higher gearing to take advantage of all their low end grunt do mid 13's at over a 100 all day long.
 

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I did a left side carb on my pan by taking a few inches off the intake manifiold and flipping around to the left side. With the manifold bolted in place like this before bolting on the carb, you can look inside and see the valve guides and a good part of the valve itself.

Besides cleaning up the right side of the engine asthetically, it allows the air/fuel charge to make a pair of 45 degree direction changes as opposed to the convetional 180 degree route on it's way to the combustion chamber. If you opt to do this mod you can also port your heads around this change to further enhance the flow.

BTW, the last few years of pan motors also benefitted from external oil lines supplying lubrication to the heads. This did cool head temps a couple of degrees.
 

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This is pretty cool but little known, The later 62 and oiler 63 to 65 panheads are called by the old guys "see through heads", with the valves removed and looking through either port, a little peak of daylight can be seen. earlier heads are not this way.
The S&S shovelheads are probably the best thing that ever happened to the old shovel. The fin in the intake port, actually stuffs the bottom of the port forcing the the mix to the top of the port and creating a bit more swirl.
The stock heads are so inconsistant in the cast cores of the ports they are a little diffacult to even balance the flow.
Any increase of port diameter is really counter productive . The cavernous ports on stock heads have dreadfull flow because of the low velocity causes the mix to go turbulant.
The head guys of old would build up the bottom of the port to kick the mixture up to the top, very much like the bump found on current heads, then the velocity would increase with improved swirl resulting in higher flow#s.
Stock shovel heads can vary extreemly widely in flow even in a set. They generaly test at the old standard 10" water and 1/2" lift from 105cfm to 120cfm. In contrast a Set of S$S heads will be around 140 cfm. Now thats an average tested with my Laminar flow element equipped bench, of course flow #s are effected by humidity,temperature and barometric pressure
The old 62 to 65 pans run around 125cfm with a more consistant balance and pretty good swirl distance, the distance from the valve to the point of turbulance down the cylinder.
I hope some find that interesting. Source of much of that was the factory.^rolleyez^
 
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