Ah, right. I can never keep straight that aspect of advertized duration, and if they or the .050" numbers are off the bace circle or after valve lash has been taken up (B.C.). The advertized durations may be similar but that Schneider gets to .050" in a hurry... it's going to be interesting, anyway!

I'll also amend my statement about the peak lift and not lasting, once again forgetting the nature of a flat top lifter. It's still probably more lift than your port will give, but that's fine too as long as the springs hold up. Which they will.

It's so frustrating that the cam guys don't give out full specs for comparison. I'm especially annoyed at Vintage Performance's cam as it cam with no card and no indication on how to degree it properly. So my current plan is to measure the VPD Street cam when the engine comes out, install the "F" then put the Schneider cam in and see what the differences are with a standard method. I think we wouldn't get confused if everyone used the same method. Having VPD report the cam duration at 0.020" (literally writing the number) was confusing as no one else notes that the advertised duration is (supposedly standardized to this lift). That made me think that the cam was more burly than it is. Then when no one else makes a note of what lift the advertised duration is measured at - it makes for confusion.

I was reading that the overlap and lobe separation is what really makes the power (and as you can compute the duration from these values, they are related) - for example, the tighter the LSA the more power you can expect (as a generalisation) so you could have the same duration numbers, but different LSA and overlaps and if you only looked at duration you'd get the wrong impression of what the cam would be like.

So we're essentially rolling the dice again...man, you'd think I didn't spend my day as a scientist (reaches for shrunken head, voodoo rattle and a coffee).

Let's see if I can get this right:

LSA doesn't really MAKE power, IMO, but it shapes the power and focuses it. In general, a tight LSA will give more peak torque/power and more torque/power within the powerband, but they'll be closer together and the powerband will be narrower. Wider LSA gives more powerband breadth but a lower overall peak.

Tight LSA = early intake events and late exhaust events. Early intake closing = more compression, late exhaust opening = more power stroke. The higher compression causes a faster and more energetic burn and the longer power stroke allows more time for expanding gasses to work on the piston, but because there's less time for each port to work, the top end is limited by the head flow, while the bottom end is limited by the reversion and lack of scavenging below the powerband. Tight LSA requires a good head and good scavenging, plus an intake insensitive to reversion (speed density and good runner separation).

This is all related to R/S ratio too. A long R/S ratio moves the piston slower in the top half of the stroke, and it spends more time near TDC. The piston is always higher in the stroke anywhere except for TDC and BDC, basically, so the intake closes with the piston higher in the bore and the exhaust opens with the piston higher in the bore, much like a wider LSA cam. At overlap, the piston doesn't move as far while both valves are open, so there will be less piston-motion-influenced scavenging issues - it's all based on gas velocity, and scavenging can happen easier. This is why a long R/S ratio engine can accept (and should get) a tighter LSA cam than a short R/S ratio engine, and why a long R/S ratio engine tends to make less peak torque than a short R/S ratio engine, all things being equal, but has a broader powerband.

I finally got an extended period in the garage to do the flow measurements on the exhaust port modified for the larger 38 mm valve. The valves used were from KG Trimning and have had a 30 degree back-cut. I've modified my basic seat shape to include a fourth angle and I don't let the machine shop hog the throat, I get them to taper the cut and then let me do the blending. It's hard to photograph, but here's the port shape as I get it back from the machine shop.



You can see where the taper ends in the valve bowl - this is where I blend from. I'm doing this to attempt to keep the flow velocities up and to reconverge the gasses past the tulip of the valve.

Here's the blend.



As I'm only playing with this head, this port was only finished to 180 grit and not fully polished to perfection.

Here's the exit.


Now for the flow numbers. The values are not corrected to CFM, but are relative flow values. The chart titles explain where the measurements were taken (Right - Exit - Bottom is the right hand side of the port, at the port exit, measured on the bottom of the port). These tests are being done to evaluate the relative merits of welding up the exhaust ports.

Here's the right side of the port graphs. The slanted port is shallowest on the right side.


This is the left side graphs.


It's clear that the larger valve flows more air and that raising the port improves the quality of the flow. Things that are not apparent in the numbers was the nature of the flow variations in the port. Both raised port variatons are more consistent with respect to flow distribution. The straight porting seemed to amplify the variatons inherent in the port. I noticed much larger negative pressures (20 on my relative scale is atmospheric pressure - so values over 20 is vacuum) and the port prob was harder to keep in a constant position. This cleaned up as soon as the floor of the port was raised. I think what this is telling me is that there is less turbulance and I can verify that there is more flow velocity for a constant air flow.

That's it for this experiment - I'll weld up the floors and keep them level.

don't have anything to add on the mechnical side of things however, I did find more CVC decals today (back glass shattered)

next time you are in Calgary or I am in Lethbridge we shall meet up, I will have some in my truck

cheers

Awesome - I need a replacement when I get done.

Here's yesterday's adventure. I was going to put in a 70 A alternator from a 740 in place of my 45 A unit as I may need a little more power for all the EFI stuff. I did a test fit and it will work, but it sure does take up some space. I found a guy on TB selling a 100 A Denso from a 940 that looked like it would do the trick. It's significantly smaller and lighter (the 70 A can go in the 240 at some point). I built an adapter bracket based on the old generator mount. I've been really wanting to get these parts done so I can get the project moving. The alternator is required for making the header and I need to get the power steering pump mounted so I can be sure it will all fit.

This is the bracket (I did oval the block mount holes to ensure that my pulley aligment is perfect).
Note the steel sleeves that I used in the mount holes - this should hold.



100 A alternator mounted.



Installed. It fits perfectly and is a finger off the existing cast manifold. I'm going to plumb the header up and over that part a little better.

More progress was made this week despite my best efforts. The head is now back in my garage. Just to recap, it's a late B20B (based on the late B20F casting, it measured 3.40" thick) modified with new 38 mm / 44 mm exhaust/intake valves from KG Trimning and fancy hardened seats on the exhaust side. I welded up the exhaust port and am still working on the porting. The valve bowl area on the exhaust side is a slightly different shape than I was expecting, but it's fine and I have to do a lot of blending to get it all flowing as well as it can.

The fun part was all the combustion chamber work that I did on this head. I hadn't done much work in the combustion chambers previously and I knew that the walls of the chamber were shrouding the valves. So I came up with the shape that I think will work. It's a variation of others that I've seen that are reported to work.

The goal for this engine was to make more HP and with the cam that I selected, this means more compression...how much more....well how about 11:1! This is what is "supposed" to work. I've checked with pipemax and with the cam overlap, the dynamic compression is in a safe range and I do recall that the B20E had 10.5:1 from the factory so it's not that nuts to go to 11:1.

This does mean that the head had to shrink rather a lot. The B20 (well all the pushrod engines) get their compression from the size of the combustion chamber and came in the following variants:

B20A 3.41"
B20B 3.39"
B20E 3.31"
B20F 3.42"

These engines also got different head gasket thicknesses:

B20A .055" (1.4 mm) unloaded --- .047 (1.2 mm) loaded
B20B .031" (0.8 mm) unloaded --- .028 (0 .7 mm) loaded
B20E .031" (0.8 mm) unloaded --- .028 ( 0.7 mm) loaded
B20F .047" (1.2 mm) unloaded --- .039 (1 mm) loaded

I've got a variety of head gaskets at my disposal and with my bottom end (pistons coming out of the block 4 thou) the B20F should be the winner (this is what I used for calculations).

Off to the machine shop with 45 cc's of volume being the goal.

Set the head in the surfacing machine (after a few passes on the belt sander to flatten the intake/exhaust side). Doug the machinist sets things up and zero's the head.



He then took a few passes to see how warped the head was as a result of my welding. It cleaned up in only 2 passes and 6 thou.

Then I cc'ed the head, and it was a whopping 66 cc's

Here it is at 66 cc's:



90 thou worth of milling later and we had the 45 cc's that I needed...I was getting worried, but the machine shop guys were egging me on. What the heck right - making horsepower is not for the faint of heart. Here it is at 45 cc's on the nut for volume. This took 2 hours of machining.



Here's the final head height 3.316" (my pistons come up further than stock). So it's not any thinner than a stock B20E head. Should be fine.



Just for reference, here's a B20F head.



This shold be fun.

Just wondering if anyone is intersted in my T5 transmission rebuild. I can photo everything and post "how-to" details if folks think it's worth the effort.

Definitely!

Yeah, that would be good!

OK - here's my shot at chronicling this adventure. I haven't found much on the interwebz for doing this step by step. It's usually described as being "easy" so let's have a look at how easy this is likely to be. To start this adventure, let me begin by saying that there is nothing wrong with the M41 in the car, I'm just doing this "upgrade" to ensure I don't want to change it later and find that it won't fit into my car.

The following were acquired at various points in time in the near and distant past:

1. 240 transmission tunnel - because you need something that has a rear shifter location.
2. T5 adapter and clutch fork with throw-out bearing and new pilot bearing.

New parts:

1. The dirty T5 from a late 1986 5 L Mustang - that makes it a World Class T5 (as do the tapered roller bearings).
2. Short throw shifter from MGW (http://www.mgwltd.com/mustang_shifter.shtml)
3. Rebuild parts from Astro Performance (https://astroperformance.com/)

Here's what it looked like at the start - Ford didn't use gaskets apparently!



7 cans of brake clean later and it was clean enough to take home from Matt's garage.

The tranny was then stripped and cleaned. I read the manual after, but it wasn't very hard. There is a couple of roll pins to knock out of the shifter and then the transmisson cases could be separated. The top cover is easy to remove (and this one has been rebuilt - so breaking the RTV "gaskets" was ok as the rebuilders didn't really know how to use RTV and the bolts were easy to remove as they were never cleaned so the thread sealant over old sealant wasn't presenting much difficulty).

The bearing retainer was removed when the bell housing bolts finally gave way to my impact wrench (different torque settings between bolts is a "feature" of this rebuild). The input shaft comes right out (with a pile of roller bearings - which will be replaced). Then the main input shaft was removed when the 5th gear fork, slider and synchro were removed (sorry no pics). The intermediate shaft was hard to remove as the bearing cage on 1st has to be broken to get it out. I don't think these bearings were ever replaced. The races had ridges and were probably fine, but the rebuild kits include new bearings for a reason.

Inspection time (with pics). Things to remember when rebuilding transmissions - the gears are constantly in mesh with the intermediate shaft. The nasty crunching noise you hear is NOT your gears clashing when you miss a shift, it's the shift dogs that allow the gears to syncronize speeds. They are little things and damage easily.

Here's the main shaft:

Note that it's pretty clean in the trans case - this is a good sign.

Let's see those dogs:

The black ring is the syncro (looks new) and the slider has the grove that connects to the shift fork. Second gear is in the middle of the frame and you can see how the ends of the dogs are not pointy. The wear here would lead to a difficult 1/2 shift (slider moving from back to front). These dogs mate to the slider - so if they're looking like this you have to replace both parts. Gear was $132 and the slider was $45. Third gear wasn't bad, but while I was buying stuff, I replaced it as well.

The reverse idler gear also gets some abuse and I don't like transmissions that have hard to engage reverse gears. So it gets tossed as well. Note the rounded leading edge of the teeth - not good.


Inspect all gears for chips and wear. They should be fine, but aren't particularly expensive if you have any doubt, replace. Everything else in my transmission seemed fine. I'll be deburring them a little better than the factory did before everything goes back together...but it's not needed.

Parts like this bearing retainer and throw out bearing guide are subject to wear...why keep a part like this when the scrap guys will give me a nickel for it?


If you're considering this sort of rebuild, it's good to keep in mind that a Ford Racing rebuild is only $1600. Now let's consider that you're doing this for the long haul and are replacing the bearings. They all have to come off and they all PRESS on - so getting them off is difficult. I have taken a lot of bearings off in my life, so I figured I'd share.

There are three different approaches:

1. Once the cage and rollers have been removed (grind, pry etc.) - if you can get a cold chisel on the edge of the bearing race, you can tap them off.
This bearing inner race was removed this way. Just tap it out.


2. Cut a grove on both sides of the bearing with either a grinder or cut-off tool, insert cold chisel into the grove (don't grind too far and hit the shaft). Give it a whack (supported by wood) and it will break like this.



3. Use a bearing puller. No pics - works like a bearing puller for heaven's sake.

OK - now for some cleaning, and there is a lot of cleaning (like 2 full days) to do for this job.
The case was bead blasted once the crud was removed. You can't blast grease - so it's got to be clean before it gets blasted. Into the blast cabinet it goes for stage 1.

There are three parts to do - here they are done.


Looks like new.


Then all threaded holes are chased with a tap (they were filty) and all parts were deburred. It seems that Borg-Warner didn't believe in deburring anything! Sharp edges everywhere. They all were dealt with as well as some smoothing of casting flash that will shred you during installation. I also noticed that many of the clearance holes were not deburred. Technically, if two faces meet and one face is threaded, then the clearance hole needs to be relieved so that it doesn't restrict the hole deformation during torquing. All threaded holes are countersunk for the same reason. I'm not surprised this detail was missed - but I did it anyway. The cases are sealed with RTV, so they have to be flat as well, a quick once over with a file ensures that the faces are perfectly flat.

All other parts are tossed into the parts washer and varsol soaked with the pump running over night. The result is very dirty varsol and some moderately clean parts. Varsol is then tossed (you can't clean parts with dirty cleaner) and the parts are further cleaned with brushes.



Bolts and other filthy things are subjected to another separate washing (gotta keep the clean fluid clean). Clean parts are placed in a tray (cheap at Can Tire at Thanksgiving time) with a rack to dry. All parts are cleaned and brushed at least twice until perfectly clean.


So that's the entire deal on the first stage - all new bolts were purchsed (only 2 on the top cover that are special will be reused) - I don't care how much you like your greasy bolts, unless you have a good reason to reuse the old ones (and I cleaned them in case I need them) - they are junk and cheap to replace with nice new bolts. If you have to loctite bolts, clean new bolts are needed to ensure proper chemical bonding.

Everything is now put away clean with bolts waiting for my parts shipment from Astro Performance.



One part I couldn't get off was 5th gear. The stock overdrive ratio was 0.68...which is pretty tall. It's getting replaced with a Chevy set that yields 0.83 overdrive. Final ratios will look like this (6500 rpm redline with new 3.91 rear drive ratio):

Wow! Looks great Craig! Love seeing how clean that case came out. Great to see this coming together.

Now I just have to decide if I'm painting it or not. Raw aluminum looks great for a bit, but looks pretty bad right after that. I should use up some of my "silver" collection of paint on it.

Good plan. Or you could just clear it.

Maybe red...