Topic: A 1972 turbo swap adventure

[65ShelbyClone]

My understanding is the turbo kills a lot of the velocity in the exhaust thus the large diameter compensates for that.   My single 2-1/4" is likely a deficit I'd like to change someday. I'm not seeking the high HP output some of you guys are, but I'd still like to maximize what I have in its stock form.

Turbos don't decrease the exhaust velocity; they just work better when restriction downstream of the turbine is kept to an absolute minimum.

Stock exhaust size for any 2.3T car was 2.25" as far as I know. In hindsight, 2.5" is probably as large as I would go for a sub-300hp street car. Pintos are unarguably the most spacious little cars from that era, but I can see that Ford got that space by taking it from every other part of the chassis.

In other news, I started toward moving the alternator to the driver's side. What I found out was:
1.) The upper Pinto alternator bracket hits the "late" EFI intake manifold flange and won't fit without modifying the bracket.
2.) Same thing for the marine alternator bracket I have, although not as bad.
3.) The alternator is probably going to hit the battery anyway. Remember that billet tray I made to put it on the driver's side of the engine bay? Yeah, probably coming out.

The cooling system(or lack thereof) is also floating higher on the to-do list. My drive home yesterday saw coolant temps struggling to dip below 215°F when outside temps were only in the upper 80s. The electric pusher fan does practically nothing unless the car is stopped.

65ShelbyClone, the exhaust is looking good.  I like the idea of caring a window shade to use as a emergency work mat.

Thanks. That's not the primary reason I carry a window shade,  but I was wingin' it at the time. Usually I just carry a small tarp. (Very) creative solutions are something I have had to learn for my job and it bled over. 

[Wittsend]

I have my alternator on the drivers side.  I made the bracket out of a old bed rail angle iron.  The contact wrap on the water pump pulley is minimal, but it has never been a problem. Also somewhat tight at the battery, but enough clearance.  Knowing the fabricator you are I'm sure you will produce something nice.  Here are a few pics of the fitment.

Note the notching for the timing belt cover, and, because of a tab on the alternator, notching too. That could have been cut off, but if I ever needed to replace it in traveling I wanted it to be replaceable without alteration. I forgot what I used as an anchor on the other end, but it was some factory 2.3 bracket. See lower edge of last picture.

[65ShelbyClone]

Is that alternator smaller than a regular one? It looks like it. I had a brainwave today that maybe a compact alternator would work. I have a 3G now and it's pretty big.

I also have a high mount bracket like yours, but am a bit more restricted by plans to run a forward-facing intake and FMIC.

Hear that funky noise?


And there's this in the feasibility study...

[Wittsend]

Whatever the stock alternator that came on a '88 T/C is what it is.  The mount on the head is not stock, but very common on 2.3 engines. The self serve yards are full of the import mini alternators.  They seem to cram nicely into tight spaces.  I've included a few pics of one I have on my Tiger. The original generator hung out wide and high. So much so the factory indented the inner fender for it. The pivot point is on the head and the front braces at the water pump with a second, bottom (unseen) bracket off the same bolt being slotted for adjustment.

That turbo should create a nice vacuum in front of the Pinto so as to draw the car quickly forward! 

[bbobcat75]

man that turbo look sweet!!!

[65ShelbyClone]

Grabbed a couple cheap rebuilt oval-port 2.3 heads and another E6 turbo manifold this week, all destined for porting.


I also have some Ferrea big valves coming in.

And.....oh no, what have I done?


I needed another turbo like I need a hole in my head, but it was fairly cheap and won't be as difficult to fit in the Pinto as the Borg Warner in my previous posts. This is a Holset HY35W-A with a 56mm compressor and 9cm hot housing that make it good for a spiced-up 2.3T. Unfortunately the bearings and compressor wheel are junk so I'm looking into getting it rebuilt and upgraded to HE351 (60mm) spec. Some people with other twin-cam 16v cars have made upwards of 600bhp on the HE351, but it will work at 250hp-300hp (my initial target) just fine as well.

[82expghost]

Hy35g and you have the same turbo watercooled

Sent from my E6782 using Tapatalk

[65ShelbyClone]

That's good to know. It looks like the "G" is Holset-ese for a natural gas application. One thing I have noticed about Holsets transplanted onto high-EGT gas engines is that they seem to suffer from the heat a bit. Maybe not enough to fail, but possibly enough to shorten their life.

[65ShelbyClone]

After a lot of whittling on a lathe, a 6" round of Delrin became a 4.375" round of Delrin. It was then given to a CNC mill with a toothy beak that did this:


to get here:


So this could be done:


To achieve this:


Now the air filter sits below the hood.

[65ShelbyClone]

I think I might have a problem. Really.


This time it's an HE341. The only difference between it an an HE351 is the 56mm compressor and physically smaller housing. This one has a stuck wastegate flapper, but I think the HY35 housing will fit on it.

Speaking of the HY35, it's the reason I have an HE341 now. The HY35's shaft journals are still in spec and they feel smooth, but there is evidence of friction-related heat. Also to my dismay was finding that the turbine had been hitting the housing as well. The turbine wheel can probably be balanced and used, but the HE341 cartridge seems to have life left. I'll know more when the housings come off. Until then, here's some hurt HY35:

I also have some Ferrea big valves coming in.

And they're purdy.

[Wittsend]

I always find you posts to be engaging.  Probably because you dare to go where I fear to tread!

Two questions:

1. Are any turbo wheels clocked with a key?  I loosened up my intake wheel to clean behind it, got it loose and realized it spun free on the shaft. As best I could I immediately rotated it back to the approximate area it was and then marked the wheels.  I always wondered about the balance but have been thankful that "close enough" indexing has not displayed any problems - yet. It has been about 2,000 miles without issue. Are they balanced independently and it doesn't matter. The turbo is an '88 IHI.

2. How are the valves swirl polished. I have a car guy/machinist friend and even he wondered.

OK, a third question:

3. Static compression is lowered to compensate for the added volume on a turbo motor such as the case in the T/C engine.  It would seem that much like one measures dynamic compression as it relates to the cam, similar aspects would seem to apply to larger turbos. It would seem that as the turbo got larger and the PSI increased you reach a peak cylinder pressure that you should not exceed. Yet when I hear of Indy type cars with boost over 40 PSI it makes me wonder what (static) compression ratio those cars run???

[65ShelbyClone]

I don't know why, but I don't always get reply notifications on this thread even though I have it set to instant email. 

Haven't done anything to the car since last; just picked up a few more tchotchkes like a new steering rack (in transit) and an amazingly cheap Chinese piston-type blow off valve that is green like my ride  . The plan is to replace the heavy brass piston with one machined from Delrin for faster response.

I also polished the burnt bearing journals on the turbine shaft above. It looks like new, but turns out the shaft is bent out of spec making it a pretty paperweight.

1. Are any turbo wheels clocked with a key?

Not any I've ever heard of. A key would cause balance and strength issues. Freedom of rotation also allows for balancing without grinding on anything; sometimes just rotating the compressor is enough to bring the assembly into spec.

Holset rebuild manuals instruct to permanently mark the wheel and shaft so they can be aligned on reassembly.

2. How are the valves swirl polished. I have a car guy/machinist friend and even he wondered.

I actually don't know how, but the most plausible reasons why seem to be manufacturing and marketing. Titanium valves are never swirl polished and many modern stainless race valves aren't either.

OK, a third question:

3. Static compression is lowered to compensate for the added volume on a turbo motor such as the case in the T/C engine.  It would seem that much like one measures dynamic compression as it relates to the cam, similar aspects would seem to apply to larger turbos. It would seem that as the turbo got larger and the PSI increased you reach a peak cylinder pressure that you should not exceed. Yet when I hear of Indy type cars with boost over 40 PSI it makes me wonder what (static) compression ratio those cars run???

You're talking about effective compression ratio.

Effective compression takes intake charge density into account. If you stuff two volumes of air into one volume of space, that's a 2:1 compression ratio. Atmospheric pressure is about 14.7psi absolute. 14.7psi of boost on top of that means that two volumes of air are in the cylinder before the piston starts to compress anything. With an 8:1 compression ratio like a 2.3T has, you get 2 x 8 = 16:1 effective compression. That's pretty high for pump gas already and 20:1 is nearing the ragged edge for a 2.3T, but it's nowhere near what methanol can tolerate. That's what Indy engines used to use. Now they use E85 which isn't as forgiving, but is still a lot nicer in that regard than pump gas.

Turbo F1 cars reached as much as 80psi of boost in the 1986 season. The BMWs had 7.5:1 static compression, so ~41.3:1 effective...

[65ShelbyClone]

I made a lightweight Delrin replacement for the brass piston in the Chinese $18.50 blow off valve mentioned previously. The Holset turbo I plan on using initially is known for not being the most tolerant of surge or slow blow off valves, so I wanted this one to open as fast as possible. The brass piston is amazingly heavy.




The sealing lip heights aren't the same because it was a non-critical dimension. The spring pocket to sealing edge dims are the same and I had to open up the piston-bore clearance to allow for Delrin's higher expansion rate, so I left the slight extra length.

[65ShelbyClone]

Quick question for anyone watching: will the drum brakes from a 6.75" rear fit on a Mustang II 8"?

No problem if they don't; I have just read about the MII brakes being a little wider and affecting the brake bias. If I can avoid playing with proportioning valves and brakes cylinders, so much the better.

[dick1172762]

74/80 brake drums are the same as Mustang II. 71/73 Pinto drums are narrow when compared to the 74/80 Pintos drums.

[oldkayaker]

The hubs on the 71/73 cars are smaller than the 74/80 Pinto's and Mustang II's.  So your 72 drums will not fit over the larger Mustang II hub with out modification.  From vague recall, the wagons and 73 and later sedans had the wider drums with some cooling fins plus a little larger hydraulic brake wheel cylinder, so you will get a little more rear bias.  I put a Mustang II 8" with brakes in my 71 and did not notice the different brake bias but I am not good at sensing such things.

[65ShelbyClone]

Thanks for the info. 

From what I could find, it looks like the 7/8" wheel cylinders were used for all models while the shoes are wider for MIIs and Pinto wagons.  In addition to stock, I also got some 13/16" wheel cylinders (1/16" smaller) to try if the rear bias is too much.

As long as the backing plates interchange, I'll be all set. The center hole is no problem; I can either open up the drum, turn-down the hub pilot on the axles, use the brakes off of the '77 Pinto parts car, or use the brakes that came with the 8". It's good to have options. 

[Wittsend]

I can confirm that the 6.75" 73 wagon rear drums do not fit a 8".  As mentioned the center hole in the drum is too small.  Not sure about the backing plates but I recall something was different between the Mustang II and the Pinto - might have had to do with the E brake cable???  I'd turn the drum as the later/larger holed drums are probably easier to find. Turning the axle will force the use of replacement drums with smaller holes.

[oldkayaker]

That wheel cylinder size did not seem right so I check Rock Auto (handy site).  The 72 sedan rear wheel cylinder was 23/32" while the wagon, 74/80 Pinto, and Mustang II used a 7/8" (look at the cylinder rebuild kits for sizes).  Note Rock Auto is doing a "wholesaler closeout" on the 23/32" stuff so replacement parts will be harder to get in the future.  That 23/32" cylinder was a pain to rebuild too, my 3-stone hone would not fit inside it.  Using the torques listed in the Ford manuals, the bolts used to connect the cylinder to the backing plate are smaller for the 23/32" than the 7/8" cylinder.  So some accommodation may be needed if swapping cylinder sizes without swapping backing plates.

[65ShelbyClone]

It looks like you're right and I ordered the "wrong" parts from Rock. That said, some quick sleuthing suggests that the master cylinders were the same diameter across all years, so I'm just not going to sweat it. The MII rear end is getting MII brakes.

I'm doing dual 2.25" tips out the side to finish off the exhaust. You all may remember from eons ago that I put the muffler under the middle of the car and kinda stopped there. It's not call-the-cops loud anymore, but interior resonance is bad. Really bad. That resonance is gone when piped all the way out the side.

Poll: should I do staggered straight-cut pipes or slash-cut them to align with the body?





In other news, I pulled the 2.3 out of my '77 parts car.


Only to find this under the #3 exhaust port:


 

Incidentally, I had to pull the clutch for the engine stand to fit on the block. Check the date on that disc:


That's "SEP 17 1976", 40 years ago to the day. 

[65ShelbyClone]

Oops! Forgot that I did some milling on an E6 manifold a few weeks ago. It was minor stuff and I didn't want to Twitterize this thread.

[65ShelbyClone]

This was from Labor Day weekend. I call it my boomstick.






The video was impromptu and not very good, so I'll try for better shots later, maybe this weekend.

[74 PintoWagon]

I like that "boomstick".

[65ShelbyClone]

For now, these are the "meh" videos.

https://www.youtube.com/watch?v=ZVl7DuitJko&feature=youtu.be

https://www.youtube.com/watch?v=6P-tuWEZFVU&feature=youtu.be

[74 PintoWagon]

Sounds pretty good..

[Wittsend]

The "Broomstick." Sweeping the edge of the highway - one mile at a time. :-)

BTW, I'm thinking the "aligned to the body" look would be best with a slight projection beyond the rocker.  Might even paint the last 1/4" or so silver. But it is your car so do as you like.

[65ShelbyClone]

Scraping the edge of the highway is more like it. New rear shocks may be in order....unles s Los Angeles County decides to start using road funds to fix the roads. 

[65ShelbyClone]

I wanted to post something by October 30th to make it an even month, but have been down with a knarly cold for the last week...my first in several years.  Getting better though, so on with the show.

The upper intake is slowly coming together. A die grinder and carbide burr were used to radius the flange holes.



Which produced slivers galore. I was picking them out of my hands for DAYS.


I should have/would have started with aluminum, but the flange was made before I had a TIG welder.

At least now there's this:


There is also a throttle body flange ready for the upper intake now. I opted to use a standard Ford 5.0 pattern for future convenience. The installed TB will be a more compact 65mm one from a 4.6L Mustang which necessitates an adapter plate. Billet again.


If anyone is wondering why I didn't just put both patterns in the steel flange, it's because the 4.6L bolt circle intersects the tubing that the flange will get welded to. I could have taken measures to seal them, but this flange is more versatile and can be used on any old 5.0 HO upper intake.

Turns out that the green blow off valve is a Taiwanese copy of a '90s-era Turbosmart Type II. They are still going for only $16 apiece otd, so I bought two more, one silver and another green. Might get a few other colors later...

The original green one has been modified extensively. The spring force was really high even with the adjuster backed off all the way. Replacement springs in other rates are hard to find and cost prohibitive, so I improvised by making a billet top hat that increases the installed height and thus, lowers the installed force. It will take some fine tuning to get it right for the peak vacuum my engine makes, but at least now that adjustment is possible.







The outlet hols have also been opened up into large slots for less restriction. I might make the ends more rectangular so there isn't an ugly silver/green border on the cuts.

[65ShelbyClone]

Small update...





This is the handle of a telescoping magnet used to check hood clearance over the TB inlet. It's amazing that the huge flange behind it fits.

[Wittsend]

"It's amazing that the huge flange behind it fits."

I'd say so. With the shorter stock set up I had to file the factory flange to the edge of the bolt holes for clearance (see pic). And in my case that was near the higher center of the hood. In your case you have the throttle body going offset from the engine center and going forward. Both those directions have hood slope that diminish clearance. Glad you found so much clearance. I can't imaging you have the engine any lower than mine. With the stock starter it hits the steering rack hold down bolt with the slightest throttle application.


So, I've searched Pick Your Part for years for a decent white hood (want to keep the original color and patina). I've wanted one as a replacement since I cut the air inlet for the factory intercooler.  Never found one. And yet here you are with a green car and - a white hood. Why does it always work out that way???


Glad to see the project moving forward even if slowly. Too often they die into obscurity.