Changing Intake ports to a D shape for better flow.

I feel like Grasshopper in Kung Fu. In awe, over my head, but still learning.

Thank you again for sharing.
I was alright until the flow ratings went on , they mean nothing to me, but I'm not an engineer.
The bit I am a bit confused with is the size of the port, I has assumed the d was coming up from the base the increase velocity as everyone keeps saying the ports are over size to begin with,
 
Gary, you wanted a photo of me and Bobby,I'm in the green jacket. The other photo is of Bobby and Charlie,who cut the valves down for me.
bobbe and me.jpg
bobby and charlie.jpg
 
Well this second trip was a success but I had to make some compromises in the left port to equalize port flow and was able to get it within 1%
which was pure luck on my side. On the right port I cut the corners down just a hair and rolled just the corners over slightly,result was I lost
2 cfms at 100,gained 2 cfms at 200,gained 11.52 cfms at 300,gained 4.15 cfms at 400 and 450 lift was 224.25 and left port after working the S/T
same method working the floor corners.
lost 5.76 cfms at 100,lost 12.24 cfms at 200,lost 9.91 cfms at 300,lost 1.42 cfms at 400 and 450 lifts was 225.
Left port
87.84
125.28
192.44
215.08
225
Right port
90
127.44
195.27
212.25
224.25
Right exhaust port flowed 89.25,120,136.73,145.58 didn't flow at 450 lift,no need to.
 
I was alright until the flow ratings went on , they mean nothing to me, but I'm not an engineer.
The bit I am a bit confused with is the size of the port, I has assumed the d was coming up from the base the increase velocity as everyone keeps saying the ports are over size to begin with,
By raising the floor you accomplish several things, you reduce the cross sectional at the short turn increasing port velocity and along the roof long side
of the bowl and by raising the floor you increase the short turn height,which enhances the flow momentum over the short turn increasing flow velocity
and CFMs. The tricky part is getting the short turn radius right allowing you shift flow lower in the flow curve to cam spec lifts of lower lifts broadening
the power band and torque curve for better street ability performance.
 
Very nice news:thumbsup: In regards to the video you can try to use the service from wetransfer.com. It should work from your phone. As reciver you can fill my mail address. I will then prepare the video for upload to this thread. Or you go the YouTube route, that should make the vid immortal;). How you like it:)
 
I know some of you have read where I mention how efficient the exhaust ports can get when the conditions are right,well I took and extra head along
this second time around to flow this E/P that I've been playing with,the air was COLD AND DENSE
100 lift 116.73, 200 lift 146.51,300 lift 156.98 ,400 lift 208.58, you wouldn't want this E/P under any conditions cuz the flow ratios are off the charts but
it sure sounded good on the bench pushing that air;)
 
Very nice news:thumbsup: In regards to the video you can try to use the service from wetransfer.com. It should work from your phone. As reciver you can fill my mail address. I will then prepare the video for upload to this thread. Or you go the YouTube route, that should make the vid immortal;). How you like it:)
I will try
 
Plans for this year is to build a flow bench for porting my own head ,will either be PTS bench,Dtec bench or Flow Quik. will have four Ametec motors with motor speed control. Depressions goals are 25" 0r 28" without blowing the 30 amp breaker.:whistle: might have to use 220V motors.
 
engine.jpg cam mit lagern.jpg kugelkopf.jpg mopet.jpg deckel.jpg Hello,

here we go! The head arrived here safely! It's a piece of beautiful work. Actually, I wanted to install the head later, but since I have much more time now because of Corona, I can't do anything else. And my old head loses oil from the points/centrifugal governor housing. So I will install the head now.

Instead of the bearings from the XS dealer (a shop with many parts MikesXS also sells) I simply bought brand bearings and brand Viton shaft seals from the specialized trade. This bearings are the same, the shaft seals better quality without the XS Shops extra charge:) I´m going with elephant food adjusters instead of the oem parts. In the past I made good experiences.

In the past I had many times problems with the points/centrifugal governor housing tightness. Therefore I wanted to do it exactly this time. In the German forum we can find a post from our Swiss Steffi with very good instruction for the exact fitting of the camshaft bearings / centering of the camshaft. After this method everything should be tight and well centred.
Maybe this method is already known here?
Anyway, I will documented this in a future post as good as i can (but thats not my favorit business).

In the next days i transplant the engine back in to the frame.

Unfortunately I can't do any longer tour because of the Corona. At the moment I can only drive to work or shopping and make a little extra round. As soon as I have gained some experience I will get back to you with my impressions.


Stay calm and healthy!
 
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Camshaft install method:

1. insert the 4 bearings and double check if the cam timing marks are spot on!
2 Lager drauf schieben.jpg

2. !! install and pre-tension the timing chain tensioner !!

3. put on a cover !!without!! seal and O-Ring
deckel ohne 3a dichtungen.jpg 3b deckel ohne dichtungen montieren.jpg

4. gently press the whole thing against the lid on the opposite side with a rubber mallet
4 gegen deckel drücken.jpg

5. Place the cover on the other side and measure the gap between the housing and the sealing surface of the head with a feeler gauge
6 spalt messen.jpg

6. Gently halve the gap with a rubber mallet on lid
5 deckel an andere Seite.jpg

7. countercheck. Goal ist there is the same distance on points/advance side between cover < -- > sealing surface head (in this Photo the bearings are not fully in line with cam, in this stage of assembly they should be as near as possible to the cam)
gap.jpg


Now the camshaft bearings are as far inside as possible. With installed gaskets the covers where pressed against the sealing surface of the head and thus really seal and the camshaft is perfectly centered.


According to Steffi the cylinder head expands during operation by a few hundredths more than the camshaft and the camshaft gets very little lateral play.

Now the head can be further mounted...
 
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7. countercheck. Goal ist there is the same distance on points/advance side between cover < -- > sealing surface head (in this Photo the bearings are not fully in line with cam, in this stage of assembly they should be as near as possible to the cam)
Great write up spungle! Jim, mebbie link to this?
Well, since this is a performance engine, I'm assuming that's an aftermarket cam? I've measured 2 stock setups now, and with both side covers fully seated, you can't fit a .002" feeler between the covers and the bearings... and yes, the covers should fully seat. With a gap between the head and covers, I'd be concerned about sealing of both the mating surfaces and the cam end seal. I'll see if I can dig up some pics.
 
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I measured one for RobinC when he was having seal problems on his 77D rebuild. Here's the comment...

OK Robin..... I just pulled the rocker box from my XS1 motor and screwed the point and advance housings back on....
There were no gaskets, only o-rings on the housings. On the 4 arrows... housing to bearing and bearing to cam...... a .0015" feeler would NOT fit at any point. In other words.... with no gaskets, there's no room for misalignment in there.
So.... provided your housings seated (I bet they did), the only back and forth you'll get at the cam and bearing would be from the thickness of the gaskets.

IMG_20180716_111536.jpg
 
The more I look at that gap, the less I like it. the cam shoulder is resting against the inner race. The housings press against the outer race. When you tighten those housings down, your going to introduce some serious side loading on the bearings.
 
Hi Jim, you are right a Shell#1 get there. Here is a video of a quick mokup with no space between bearing and head surface with my old head/cam. I don't think this work good in a running engine? Not even the thermal expansion can do the trick I think? But I also can be wrong, I'm not an expert in that.

With Jack's head I have a gap of 0,30mm on each housing. The gasket thiknes is light squized 0,50mm. With no force on feeler gauge the thiknes is 1mm. I hope this squeeze force seal the gasket enough. What do you think folks?

 
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