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If your picture shows what I think. I.e the FD trigger wheel sat inside the 20b hub that is how I marked it. Marks definitely aren't in the same place though. Very odd.. I will have to look again at both pullies tomorrow to see how that is coming out wrong? Is there a pulley similar to the 20b one with different timing marks? Maybe an FC one?
Could be the picture angle but looking at your 20b pulley marks the leading one seems to be in alignment with the 'vertical' bolt holes? As I recall those holes align between the marks on mine?
Thanks
Lee
Post pictures of what you have, if I have time I will try to help.
FC is not remotely similar to the Cosmo or FD, not possible to confuse them
Count the ribs. The one I posted earlier is a completely different 20b pulley from a different engine in the shop, but as you can see the marks are exactly in the same place as my engine.
Last edited by Banzai-Racing; 08-03-16 at 05:58 PM.
Yes I can see exactly where your marks come up in reference to the trigger wheel ribs which is what I find strange. Will check my bits and posts up some pictures later. Appreciate any help getting to the bottom of this. I am going to try and verify TDC finding the apex seal in L1 plug hole if I can get something down there to see. That I think is the best option I have. My marks are not far different to yours which is all the more strange. 10degrees different max. So that would not cater for my timing showing 20degrees off. Still odd though. The only thing I can guess it could be is the engine has an FC hub as it looks like the FC hub is the same bolt pattern to the FD one in relation to the keyway. Would that show timing as advanced.. Cannot quite get my head around it. I.e you would need to retard it to get the timing in?
Thanks
Lee
I have been thinking about this some more and there is a lot or mis-information in other topics on this. But reading around I think I might have figured out how to find TDC.
So for the 13B you can use the plugs holes (assuming they are equal distance from BDC) to position the rear rotor to BDC and hence find TDC for rotor #1. by marking the pulley as the rotor tip passes centre of each plug hole and then taking the midpoint with a protractor.
On the 20B that won't work because the rotors are split 120°. However you could measure and find BDC with this method on rotor 1 and then take the point 180° around the pulley to find TDC. Seems accurate enough but does rely on being sure the plug holes are equally split around BDC. Can anyone confirm.
Blue TII has suggest a dial gauge on the rotor face down through one of the plug holes. Get the rotor around to near where you think TDC is and use a dial gauge down the plug hole to find it exactly. I imagine more likely trailing plug as a dial gauge probably won't fit down the leading one? Then check for when the chamber in the rotor is perpendicular to the plug hole. i.e the gauge stops moving and than starts dropping back. That will show you TDC on that rotor. This assumes the chamber on the rotor to be a flat surface across the plug holes? Can anyone confirm this please? Crap on the rotor could give you a slight misreading but it should be pretty damn accurate if the rotor face is a flat surface adjacent to the plug holes.
Any further thoughts or corrections to what I have written?
I have also been advised to check my CAS is wired to the correct polarity as that can give a symptom like I am describing.
I will check my coils are wired correct to although I assume if Leading was plugged into Trailing and visa versa the engine would just line up on the incorrect timing mark on the pulley. i.e if you measure L1 it would line up with the trailing mark on the pulley. That is not what I have, I am around 15-20degrees off the other way (advanced)
So here is a picture of my 20b pulley and then a spare FD trigger wheel I have lined up so you cam see where the markings would translate to. Not the same place as your one? Is it the right pulley?
This evening I verified that my coils and plugs ate connected the right way around and wired correctly into the ECU. I also confirmed the CAS is wired correctly as I heard the wrong polarity at the CAS can give a similar symptom.
So it all points to wrong timing marks which sure must mean an FC pulley hub was fitted at some point? As to why my marks don't line up where Banzai racings ones do hopefully that can het cleared up too!
By the way. I was not planning to stick anything down a plug hole that might break off or fall in!
With early engines the pulley is mated to the hub, for example you can take 10 different FC pulleys and the timing marks will be slightly different on each one. This is why hub & pulley sets should be kept together as sets. The FD & Renesis engines have alignment pins which made them more accurate allowing for timing wheels. The Cosmo engine is similar in design to the FC, so it stand to reason that there are variances in the hub/pulley sets.
Just seen the picture from the email link..that is interesting?! Think mine is B series off the top of my head by the way. What is going on there. Did they change the static timing values or move the pointer?! Guess you are off trying to figure out?
Thanks for the pictures. I will try and see how the marks line up compared to the bolt holes.
Is the FC slightly different with the keyway position? it is really hard to tell. I thought the FC and FD hubs looked the same on the other thread where you posted pics of all the hubs with the FD trigger wheel mounted on them. It did look like maybe FC was slightly different though?
I am oly ever going to know for sure where TDC is now by checking suing the oil in the chamber method which i will do later in the week or at the weekend.
What happened to the other post with the difference in the 20B pullies? You never came back with what you had found?
Was that a type error and meant to say 'they are not drastically different'?
So what was with the last post image that got deleted? Had the pulley moved around a bit? So they are all the same?
This thread has lots of good information and helped me figure out what parts I had, and how to time my 20B correctly.
I purchased my FD with a 20B swap done long ago, but I am ground-up restoring it, and updating engine managment and needed to figure out some accurate timing marks.
According to the pictures previously posted it looks like I have a FD Front hub and pulley installed. My trigger wheel had some additional timing marks cut into it, probably from whoever built this car.
I laid my FD Hub and trigger wheel on top of a degree wheel, and I used some paper to eye-ball where 90 degrees was to line up the crank keyway so I could identify my additional timing marks were at 5, 15, and 25 deg BTDC
I had a Full Function Engineering HALL trigger wheel laying around for another project of mine so I decided to see how that compared, and it looks like it's also bang-on.
I recently purchased a 20B and the owner didn't know what pulley hub was on the front. Can anyone tell from this picture? I don't have a crank pulley yet to determine what hub it is. I feel like its an FD hub trying to line up the counterweight where the slot is near 3'oclock.
have you verified the accuracy with a degree wheel?
i have a hard time trusting any front hub after seeing how bad they were with the FC engines in the hub and pulley combinations through the years and the 20B is basically a combination of a FC and FD engine. when it comes to the timing being off by even a few degrees, i don't like to mess around.
Last edited by RotaryEvolution; 04-04-17 at 10:19 AM.
I personally just removed the entire hub assembly, used racing beat main pulley with timing marks to make sure the timing is good and bolted the UR pulley back up.
Quick question here, if using the FD front cover and FD trigger wheel and pulley, do you still need to find the correct timing, just tying to understand since I’m not mixing pulleys hubs or covers. Any input will be greatly appreciated as I’m starting to move forward with my build.
08-03-16, 04:39 PM
