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m.abbadessa
Samba Member
Joined: October 10, 2012
Posts: 51
Location: Phoenix, Arizona
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 Posted: Sat May 19, 2018 10:51 pm Post subject: Timing help |
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| I recently purchased a Sandrail with a type 4 1.8l out of a Porsche. I only know this because I ran the serial number on the block. This being my first engine like this I need some help identifying the timing marks. I’ve had other type 1 vw motors and would time those at 28-30 degrees with my 009 distributor. I see two visible marks through the fan shroud hole. A black little triangle and a scratch mark in another location. No numbers associated with either of these. Can someone please help guide me through the process. Thanks |
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21512
Location: Oklahoma City
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| Posted: Sun May 20, 2018 9:24 am Post subject: Re: Timing help |
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| m.abbadessa wrote: |
| I recently purchased a Sandrail with a type 4 1.8l out of a Porsche. I only know this because I ran the serial number on the block. This being my first engine like this I need some help identifying the timing marks. I’ve had other type 1 vw motors and would time those at 28-30 degrees with my 009 distributor. I see two visible marks through the fan shroud hole. A black little triangle and a scratch mark in another location. No numbers associated with either of these. Can someone please help guide me through the process. Thanks |
A couple of things. It may or may not still be a 1.8L.....and may or may not be from a Porsche. It may be from a 412. But.....the 1.8L in the 412 and 914 were identical in every way.......in the US.
My point about may or may not still be a 1.8L....is that at this late age.....it could have been rebuilt into anything from a 1.7L, to a 1.8 to a 2.0 liter....all of which had at least two factory variations.....including further variations that were tuned very difgerently for use in a bus.
For these differences in variations.....you had different cams, different compression and different distributors.....all of which required different ignition timing settings. And to facilitate that.....there were several different fans with different timing marks.....and different settings for manual or automatic transmission (in the case of 412 or bus)
And....that's just factory variations. With aftermarket parts....cams....compression.....it could be anything.
But for the moment.....we need to know what distributor your engine has.
For a 914 with 1.8L.....the timing was set at idle. The factory spec was 7.5° before top dead center at 800-900 rpm.....if you are using the stock distributor.
If you are using a 009.....which are not great for type 4 engines unless they have been reworked and recurved.....you should probably set it closer to how the 1.7L and 2.0L Porsche 914 and 411/412 engines were timed.....which is 27° BTDC at 3500 rom with vacuum hoses off.
Now.....your timing marks.....
Early 1.8's could have had two marks......a black line.....and a red one to the left of it. That black line on some models was either 5° or 7.5° ....depending on where it is in relation to the fins. The right line further to the right was 27° BTDC. On later 1.8's.....some just had the 27° BTDC red mark and others just had the 7.5° black mark. None of them had "triangles"
I will post a picture shortly to show you how to figure out what each mark is. Ray |
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21512
Location: Oklahoma City
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| Posted: Sun May 20, 2018 2:01 pm Post subject: Re: Timing help |
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Ok....this is to help someone...anyone with a type 4 engine...whether its a 1.7L, 1.8L or 2.0L or a custom displacement.....that is using a stock crankshaft mounted fan.....set up basic timing marks if you do not have a fan with marks (like one from a late bus)...or you are not sure of the correct marks.
Getting oriented first:
With the engine at TDC on #1 cylinder. Almost all 914 1.7L and 2.0L had a "0/TDC" mark. Some 1.8L did not. You really need to know "0" on all engines for a variety of purposes.
When looking through the hole in the fan shroud from above...."0" will appear in that "V" notch in the fan shroud and will line up with the centerline of the two case halves....always.
Looking from the pulley side of the fan when its bolted onto the engine....here is the basic orientation. The "0" will be at 12 o'clock...the lug that connects with the dowel pin on the crankshaft mounting hub will be between 10 and 11 o'clock.
The 7.5° mark will be about 1/2 fin to the right of the "0" mark. The 27° BTDC mark (red mark) is three fins further to the right of the 7.5° mark.
So if you do not have a "0" on your fan...how do you proceed?
Ok...now that you know the locating lug orientation ...between 10 and 11 o'clock when viewing from the pullet side of the fan...you now know where the correct "quadrant" for "0" to appear is. So stand teh fan up that way in front of you.
Looking at the picture above.....from the fat support post on your left...count 6 fins over to the right...and then 1/2 of the space between fins...and the "0" goes right there....at 6.5 fins from the left.
For the 1.8L timing mark at 7.5° BTDC...go 1/2 fin more to the #7 fin...and thats where you make the mark.
For 27° BTDC...count three more fins over to your right to fin #10 and thats where the mark goes.
This will get you to pretty damn good basic timing.....but
there is a math issue:
So about right now you are looking at that 7.5° mark...and dividing 27° by 3.5 spaces...and coming up with 7.7°...right?  
Yes.....thats because....in reality...the "0" is not EXACTLY dead on between two fins.
Its actually about 2° closer to the left. Like I said...just counting half spaces will get you to good "basic" timing. So if you want to be exact.....
If you look closely...the "0" is 2° closer to the left...because the factory actually measured that "0" coming from the vertex of the crank/fan centerline.....and it corresponds to a line shot from that vertex...with the inside edge of the fan blade (yellow line). Since the fan blades are canted...you get a 2° difference in placement.
This has caused some small confusion over the years.....as they list 1.8L idle timing at 7.5°....which is close enough...because at a glance the "0" timing mark...if you have one..."seems" to be dead center between fins...but its not.
In reality.....that 1.8L black timing mark for 1.8L.....is at 7.7°....but thats not a big deal really.
Ray |
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m.abbadessa
Samba Member
Joined: October 10, 2012
Posts: 51
Location: Phoenix, Arizona
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| Posted: Sun May 20, 2018 4:35 pm Post subject: Re: Timing help |
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Ok thanks so much!
Upon further inspection I do not see a 0. But I do have a notch that is between fin 7 and 8, but is closer to the 7 fin. The black triangle I spoke of earlier is actually where someone painted this notch. My thought is to mark fin 10 with a red marker. There is currently no mark at fin 10. Am I thinking about this correct? |
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21512
Location: Oklahoma City
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| Posted: Sun May 20, 2018 5:21 pm Post subject: Re: Timing help |
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| m.abbadessa wrote: |
Ok thanks so much!
Upon further inspection I do not see a 0. But I do have a notch that is between fin 7 and 8, but is closer to the 7 fin. The black triangle I spoke of earlier is actually where someone painted this notch. My thought is to mark fin 10 with a red marker. There is currently no mark at fin 10. Am I thinking about this correct? |
The mark closest to fin #7 is the idle timing mark for a 1.8L. It is probably 7.7° by the inner edge of the fin. Very small differences by 1-2 degrees through the years. That will make no difference.
Yes....putting the red mark on fin #10 is a good idea. That is 27° BTDC.
Why the factory used 27° BTDC.....is an excellent reason. The factory distributor was a combination mechanical and vacuum advance. The vacuim advance kicked in first at a hair over 1000 rpm....and gave about 10° of advance just to allow it to smoothly get off the line until the centrifugal advance kicked in.
The centrifugal advance was set to max out at 27 BTDC....which was perfect for short stroke engine....even better on the high compression 1.7L.
So with vacuum advance hoses disconnected....you run it up to 3500 rpm which is where the torque peak and HP graph crossed with that stroke and compression.
In reality.....when driving.....the vacuum would get high again and the vacuum advance would generally....partially.... kick in again near 3200-3500 rpm and give about another 5-8° advance....so total advance at 3500-3700 rpm was right 32°-35°.
Some people can see all the way to 40° total combined advance. On a 914 or 411/412.....with the high compression (8.2:1).....and spirited driving.....this was too much. So there was a vacuum advance can available that had an adjusting screw that could limit advance so you would not get into pinging range on hard acceleration.
If you are running a full mechanical distributor....just set it at 32° at 3500 rpm as starting place. If you are running the stock 1.8 distributor with vacuum advance.....set it at 800-900 rpm idle at the black mark near fin #7....then check it to see that it does not go more than a half fin past that red mark on fin #10. That is 32°......note that in my pictures....I installed a mark there so I could check this. Ray |
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m.abbadessa
Samba Member
Joined: October 10, 2012
Posts: 51
Location: Phoenix, Arizona
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| Posted: Sun May 20, 2018 5:46 pm Post subject: Re: Timing help |
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Thanks!
The detailed responses are much appreciated! Going to fine tune it tonight!! |
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Yonder1981
Samba Member
Joined: May 22, 2019
Posts: 126
Location: Billings, MT
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| Posted: Mon May 27, 2019 9:24 am Post subject: Re: Timing help |
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I’ve been reading up on timing the 914 motor. The one in my bus doesn’t have the “0” mark but has the notches for 7.7 and 27. I did notice there is a vw stamp which lines up with the seam perfectly at TDC which is also about fun 6.5.
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21512
Location: Oklahoma City
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| Posted: Tue May 28, 2019 11:30 am Post subject: Re: Timing help |
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| Yonder1981 wrote: |
I’ve been reading up on timing the 914 motor. The one in my bus doesn’t have the “0” mark but has the notches for 7.7 and 27. I did notice there is a vw stamp which lines up with the seam perfectly at TDC which is also about fun 6.5.
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If you take a look at my original post and lists....if you have the 7.7 mark and the 27 mark...you can pretty precisely find "0".
You note that you have a "914" engine in your bus. Are you SURE its a 914 version of the 1.8L?....or simply a bus version with a 1.8L with a 914 fan/pulley assembly?
Also by the time the 1.8L came out and these cars were seriously entrenched in the dealer maintenance program...many of the 1.8L fans had no "0" mark. It was not necessary as it was not used by the dealer for timing.
Likewise....some later engines had only the 27 BTDC mark...with "0" being noted by the diagnostic sensor in the crankcase/bell housing wall and 27 BTDC being used as the dynamic timing mark at 3500 rpm.
Ray |
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Yonder1981
Samba Member
Joined: May 22, 2019
Posts: 126
Location: Billings, MT
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| Posted: Thu May 30, 2019 7:45 am Post subject: Re: Timing help |
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As far as which engine I have, that’s still to be determined. I’m not sure it’s a 914. I believe the numbers were ground off and restamped. I’ll be pulling it this week then I’ll know.
The point I was bringing up was that there is a small vw stamp on the front of the pulley where TDC should be. No one had discussed that. Not sure if it’s something that could be useful to someone who potentially doesn’t have an inspection hole. 🤷♂️ |
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21512
Location: Oklahoma City
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| Posted: Thu May 30, 2019 8:27 am Post subject: Re: Timing help |
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| Yonder1981 wrote: |
As far as which engine I have, that’s still to be determined. I’m not sure it’s a 914. I believe the numbers were ground off and restamped. I’ll be pulling it this week then I’ll know.
The point I was bringing up was that there is a small vw stamp on the front of the pulley where TDC should be. No one had discussed that. Not sure if it’s something that could be useful to someone who potentially doesn’t have an inspection hole. 🤷♂️ |
Im just assuming from the timing marks you have.....even though that may be the wrong fan.....that you have a 1.8L?????
If nothings been changed....you should be able to tell by the head part number in the r9cker box. And once you get it apart....valve size and combustion chamber shape and piston diameter will confirm 1.8L
Aside from those items....I'm not exactly sure what to tell you to look for when you tear it down....to tell you its either a 914, 412 or bus engine.
They all three had the same stroke, piston diameter, same compression, same rods, same head part numbers, same valve sizes.
Also aside from the European/UK twin carb 1.8L that came in the 412...all three 1.8L engines.....the 914, US spec 412 and the bus....they all had 7.3:1 compression.
The only differences I can find are that the bus may be creating its 7.3:l compression with a shorter deck shim and bigger dish piston.....or a smaller dish piston and thicker deck shim. They all three had dished pistons anx 7.3:1 compression.
However.....the bus produced 65hp DIN and the 914 and 412 engines with L-jet (which are 100% identical down to the last part number)....produced 76hp.
The twin carbed AN case series 914 and 412 both with twin carbs produced 85hp.
The differences I can find are ignition curve and camshaft. However I have not had a 1.8L 412/914 cam in my hand in recent enough history to measure its specs. Ray |
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