I went to remove the stationary gear from the thick intermediate and noticed the bolts felt like they weren't very tight. I grabbed the torque wrench and had a look. Turns out they were only tightened to 5 foot pounds. It's the beam type and it consistantly read just 5 foot pounds on every bolt.

Is that factory? Could they have loosened over time? They are only 10mm head 6 x 1.00 thread bolts without a hardness number but anodized black. Not sure how hard they are. Factory spec on 6x1.0 is supposed to be 5 to 7 foot pounds. I typically go up to 7 or sometimes slightly tighter if the situation calls for it.

How tight were your stationary gear bolts, and tight did you tighten them upon assembly?

Now for my porting questions. Secondaries appear similar to FD/T2, but I'll double check in a couple of minutes (I just made a quick paper template to compare them lol). Do you guys ever open the secondaries any sooner than stock? Ever close any later than stock?

As for primaries, I know they can be opened much sooner than stock, but how much sooner? To FD spec? Can or should I go any sooner than that? I'd like an idle of like 900RPM or so. How about the closing edge? I think 20B primaries and secondaries close at the same time stock but I'll check in a few minutes. It would probably be a good idea to keep them both closing together with a streetport, right?

Exhaust sleeves are already removed. I've got a set of FD/T2 sleeves waiting to go in but there is an emissions tube in the way. Can they be tapped up and out? Or crushed horizontally and removed? Someone said they're brass. Other emissions tubes I've seen before have been steel (in R5 housings). Sounds like grinding is appropriate.

This is my first '86+ engine, so this is the first time dealing with coolant seals in the side plates. Digging them out has been tough compared to in the rotor housings of '85 and older. Is there a trick? Thanks.

 

Ok FD primary and 20B secondary close exactly the same. We know they both can be ported a bit to close a little later. Good. I'll do that.

But to open the secondary sooner? That's the question. I know it cane b done, but is it necessary? I'm looking for 300 HP at 8k and 200 torque where ever it comes in, around 6k or whatever.

The 20B primary closes a little later than the 20B secondary, but it's also tilted so it's more like half the port closes later and the other half closes sooner. Huh? Weird.

Hmm, funny thought: what if I extended the secondary closing line to match the primary, as it sort of hugs the oil seal track? Then port it upward the rest of the way as a street port? Then open a little sooner, keeping the side seal in mind. It might look a little wide on top; I think I've seen ports like this before.

As for the primary, should I keep the stock tilt at the closing edge? Or fall back to a template from a streetported S4 I have kicking around here?

 

Ok, I can open the secondary a little sooner. I can also close it a little later. My previous work with 1st gen engines has given me enough experience, I think, to avoid any side seal issues.

I think I figured out why the 20B primary closes a little later than the secondary. It's because EGR air flows in and the funky stock exhaust sleeves with late opening primaries. j9fd3s explained it really well. This is how the 20B can have such late closing primaries but still retain gobs of low end torque.

I compared several templates I've got here and I arrived at a set of streetported primaries and secondaries that will be compatible with the 20B's odd primaries and also close at the same time as ported secondaries. In other words they'll both close at the same timing. Opening timing will still be a bit staggered, to keep intake air velocities up for the primary injectors.

Incidentally, 20B secondaries open AND close at 74 spec (as close as I could figure with the paper gasket I made). Only difference is the very bottom of the port; the 20B is a little lower but you could port a 74 port low like that if you chose to, just to feel special. Same otherwise. Son of a gun.

Oh another thing I figured: the primary ports closing is horizontal with the oil pan (flat surface) as a reference compared to the secondaries which have a more usual angle. This allows the primaries to close gradually compared to the secondaries which close abruptly as the side seal swipes past. By streetporting my primaries, I'll change the closing edge angle to also close abruptly. Will this be better for a future turbo? Hey I wonder how this will set up reversion waves through the intake manifold. Is rotarygod anywhere around here?