Golly. I need to digest that. Have you tried threading it to get a visual idea of what's happening?

I found it best to look at the graphs that show the port floor...the top of the port flows (no news here), raising the port floor makes the bottom of the port flow. The port job (so comparing the stock to the basic port) wakes up the valve bottom exit (SSR). It is still hard to get the flow to be consistent across the valve exit area (add in the data from the bottom centre line to see what's happening across the SSR). In all ported cases there would be a "hill" created at the SSR - lowest at the sides, highest in the middle. The exception is the stock port that would only have a slight rise in the middle position (but generally bad everywhere as the air is stalled). The basic port separates the flow lines and are able to move more air (that's what it's showing me) - it has to be moving more air as the water level is lower for about the same at the top. The only way to do that is to move more air.

The filled ports at the bottom tell a different story. If you combine the graphs, you'd loose the point of the slanted port. Differences in flow from point to point mean there is a differential across the port and this should yield vorticity. The stock port is just puking air into the area and the difference in flow velocity from the roof of the port to the non-flowing port yields negative pressure at the base of the port (suction).

Note the differences between both raised ports at the exit. The slanted port is flowing roughly the same - which means it's flowing straight out (including the centre line measure). The same can't be said for the raised port which does pretty much what the basic port is doing it's just that the reduced area is forcing the velocities up at the exit.

Screw this - let's just put a 16V in the car and be done with it! Ha, ha, ha....decent into porting madness ensues.

No real update - I've been collecting more parts. So far I've got a 90+ power steering pump to power the rack, have got material for building a few tall valve covers for the roller rockers coming this summer, valves etc from KG Trimning, and a few other odds and ends (gaskets and the like)...oh and this showed up today. It's the parts for my new intake. still have to get runners sorted, bungs for injectors and a fuel rail, but it gets closer. If nothing else, I'll have the nicest B20 intake around.

Nice!!!

Something just occurred to me as possible useful data, Craig. You're measuring velocities at the port floor, and then you move the port floor and measure velocities in a new location (the new port floor). On the non-raised ports it could be interesting to know what the port is doing at the point of th enew floor (i.e., 1/2" off the stock floor) before and after you raise it.

I have no doubt that raising the floor, and possibly getting even trickier, is the way to go. It might be meaningless data and it might just reinforce what other testing shows, but it could still be a kick.

What diameters are your trumpets? I can swing by Calgary Metal and get some aluminium tubing if you wish, and we'll get it and the flanges to you at the same time.

The data's at home - I did the "centre" port measurement in all circumstances as well. It did what you'd expect so I didn't plot it. For a given lift, the volume of air moving past the valve is changing as a result of the porting. The distribution of air in the port is moving around in response to lift and altering port shape. The valve seat at low lifts is controlling the flow (and I didn't change that, so it looks about the same) and the port shape take over as the lift increases. What I found was that the centre line measurements went up around the same as the rest of the port. I should really thread the port and see what's what.

Maybe we can play with this at Street Wheelers? I'm reading David Vizar's 2012 book on porting and Smokey Yunick's book at the same time (one's up stairs, the other is downstairs ) - so until I'm done the reading, I'm not going to finish the head. I'm quite concerned about the combustion chamber shape. I may drag the mule head into the machine shop and have them cut the valve seats and open up the exhaust and do the chamber to see what really happens.

(Ninja edit) - planning on taking the head to machine shop this afternoon.

I'm going to need some bend in the intake runners (I think)...so I have to think about tubing choices for a bit. The more important part is getting the header mocked up and then I can weave the intake into place. I'm going to pull the trigger on that expenditure soon.

I have a 4-2-1 header you can use, if you like. It's bolted to the head in the GT but there's no exhaust, so it'd be simple enough to pull for you. At least that way you can take some measurements and/or plot out some clearances. I don't know what brand it is but it's kinda old...

Deal - can I pick it up either this weekend or next week...I'll be in town both times. Had a long chat with the machine shop and we have a plan for a 4 angle valve job on each port with some smoothing of the exhaust port. I also had them practice doing a back cut on the intake valve. Should be good for a 30 degree with 30 thou between the seat and the start of the cut. They are also not going to take the plunge cut in as far so I can blend it into the valve throat without it getting too large.

Special thanks to Matt for helping me fetch this



over the weekend. Note pillow case full of random parts (formerly used to beat people that didn't pay for their "score" I'm sure). We got it from a lovely Mother/Son combination of the whitest trash you'll ever meet. Son had to go and make a few drug deals during the removal of the axle from his car. Mom is an over the top hippie and couldn't understand why all the junk could stay in the trunk. She is guilty of moving Son's stuff around so he can't find it. Son is selling all his tools (most likely to pay court fees) but is still keeping things like the engine and transmission as they are "good" and going in the next car!

We got out of there quick - he wanted to keep the "drilled rotors" and calipers. Normally I would have argued harder, but honestly, I just wanted to vamoose. Who runs drilled rotors and single piston sliding calipers? It's got a LSD (all Turbo Supras got them - though I'm sure there was some of the other sort in the house) and it should have 3.90 gears which are a step in the right direction. The only issue is it's about 150 lbs heavier than the current axle! It's like having a body in the trunk full time. I'm thinking about lightening the frame substantially. The track is wider than expected (measuring them at the JY at full droop gave me the wrong hub-hub distance) - so around 60" - I'm probably going to have to stretch the fenders as monkeying with the width is more work and makes it all custom which I don't want.

I was on the North side this weekend but never saw you, oh well....

Looks like more scope creep with the new dimensions, we won't recognize that car when you finish with it.

Don't forget the part about filthy hippy mother's filthy hippy feet! I did NOT want to see the bottoms of those bad dogs - the tops were gnarly enough!

Edit - who needs flares?

It ain't that wide...that's the guy from Abbotsford who has grafted an SC300 onto his 122...the rear is apparently about the same. I've looked at several fender flare options today. Given that the existing car runs with a 58" wide rear (including spacers) - it's only 2" wider. Some tasteful flairs will be needed.

I've been away for a while - parts are continuing to come in and I've got a mountain of fabrication in front of me on the Canuck. It's coming together.

Here are a few things that have arrived (well, a cam shaft) - First up you get STICKERS and a CAM CARD when you buy from a real cam grinder. Something that I didn't get with my Vintage Performance Cam. So I had do idea where it was suppose to be when installed and I just timed it as I would a replacement cam (which is to say, I didn't do anything).



Not only do I know what to check, but they also list the spring pressures at rest and at full lift. I've got a gauge to measure spring pressure, now it will get some real use.

Here's something else you don't get with a Vintage Performance cam - a serial number that is traceable to your order (oh and the machining on this cam is beautiful). It's about $20 more than the VPD unit...but I got it in a month instead of 2 years.



Here's the fun part - look at the difference between the Schneider 284F (left) and the Volvo R-Sport "F" that I have - the lobe on the "F" is beefy across the top, but the flanks are sort of straight. The Schneider cam has more progressive lob ramps.



It's hard to tell by the rest, but here's the numbers from IanR
GRIND NAME .050 Duration Advertised Duration Overlap lift w/1.5 lift w/1.6 lobe centers intk / exh valve events @ .050 intake / exhaust btdc . abdc . bbdc . atdc . valve events @ .020 intake / exhaust btdc abdc bbdc atdc

Advertised duration for a solid lifter cam is 0.020"

R-Sport 'f' 241/250 291/300 69 .440 .469 112 / 111 8 53 56 14 30 81 81 39
VPD Street Cam - not listed 264/268 at .020 lift .4275" at valve .285" lift at the cam 110 deg lobe centers.
Schneider 284F - 240/240 284/284 .465"/.465" (0.320" at cam) Lobe 108 deg. 14 46 50 10 36 68 72 32

So here's what we know - the lobe centres are a tighter on the Schneider cam which should yield more power under the curve but give less peak (Matt - help!), but the Schneider cam has a lot more lift (at the cam or through the lifter) than either the "F" or the VPD cam. This can't be bad for an engine that is a bit wheezy.

Tighter lobe centers tend to give more peak power but less breadth to the powerband. Rumpy idle too, with more overlap. The Schneider has more peak lift but it doesn't look like that lift lasts too long, so is of limited use.

The Schneider appears to be symmetrical from lash to .050", and both intakes and exhausts are the same in this regard as well. Not exactly cutting edge, but neither is the engine really... Without flow data on the head it would be tough to nail down a really sophisticated profile in terms of lift or duration bias, opening/closing ramps, etc.

The F cam is advertized at .020" cam lift while the Schneider is advertized at .014". Opening/closing ramps are between .0005" per degree and .001" per degree, so you can assume another 12 degrees on the F cam durations when comparing them to the Schneiders's. The F would be a lot wilder, and looks to have much more area under the curve with the straighter ramps.

I seriously doubt that the VPD has that much more duration than the F cam, if they're both listed at .020" cam lift.

I hope that didn't confuse the issue too much!

Working my way through this - I'll measure it when installed to compare all three. The 0.014" that you're seeing is the valve lash recommended (cold) not the timing events. They are probably at 20 thou. I really wish I had the numbers for the VPD cam.

I've been doing more reading and the advertised duration for a solid lifter cam is usually measured at 20 thou...so the VPD cam's numbers shouldn't have been increased and the difference between the "F" and the 284F is the exhaust numbers. It's hard to know without measuring all three and seeing what the true difference is...