MG Sports Cars

Chris, you can pick those up at any chain store, look in their "help" parts display.

JB

Thanks Jim. I'll take a look next time I'm in the parts store.

Made a little more progress finally. For Christmas this year I must have been a good little boy because I got, not coal, not switches, but a brand spanking new A/C compressor for the B! So I've been a busy B making up a mount for it, which you can see in the not so great photos below. (what can I say, the light was bad on account of the snowstorm) Made from 7ga. stainless (.160", 4mm or just under 3/16" for the dimensionally challenged) and triple gusseted, two bolts give 3 point rigid attachment, with just enough clearance all around, once I bashed the inner fender a little with a bfh. What the heck, it'd already been "tweaked" a bit anyway. The compressor is a Sanden 1027S2, which is used on semi trucks, hence the 8 groove serpentine pulley. I HOPE it'll be enough to keep the roadster cool. Guess it's time to shop seriously for a condenser and an evaporator.









Jim

Wow, that looks tight!

Nice bling skills!

That's pretty cool Jim, (pun intended)
It also has the required "raccoon factor" as the lovely Lynne puts it.
If it's shiny you gotta have it!
That's pretty close to AHITH though. (another hole in the hood)
Cheers
Fred

Naw, a MBITB (mere bump in the bonnet). ;)

"Racoon Factor". I like that, it explains a lot. Anyway I'm not planning on either AHITH or MBITB. It'll clear. Shirley it will. The breather now, that I'm not so sure of but I'll change that if I have to.

I did consider removing some of the mounting lugs from the compressor, and may consider it again. It would make for a cleaner look. It would also mean this one could never be used for a core should the need arise. But I want it to be workable without doing that, again in case the need should arise. Rob is right, it is a tight fit, something which I imagine Calvin can appreciate. I need a little more clearance around the pulley, that will bump out pretty easily. Otherwise it's good.

This car has tight clearances all the way around, yet it's better in many regards than before when it was really close at the steering knuckle, driveshaft-to-ebrake pivot bolt and other places. Better mounts mean everything is more tightly controlled for less movement and that will help a lot. I've not noticed the engine of the Roadmaster moving around very much at all. It wobbles a bit at idle. If that's all this one does it'll be fine, and if needed I do have stiffer isolators.

Racoon factor, hmmm,... maybe I could buff out the compressor body... Ooooh,.... Shiny,....

Made some progress on the throttle body over the past few days, I'll try to get a photo soon but there really isn't that much to see. Still it is a complex piece to manufacture using the tools available to a small shop and presents some formidable challenges, one of which is the bore for the shaft bearings. Now the throttle shaft on this piece is unusually large, as the throttle body itself is 10 inches wide and will contain 3 butterflies in line, each of which is 2-1/2 inches in diameter and will have no trouble flowing enough air to feed the Eaton M-112 blower. However that means there has to be a hole straight down the middle of a 10" long block of aluminum, and the bore must be quite straight or the shaft will bind. I'm using four precision sealed ball bearings with an OD of 23mm and I do not have a 23mm long reamer or long drill (either of which is quite expensive) and none of my machines has more than 6" of quill travel.

Despite those difficulties I found a way but I'm afraid the details would not be that interesting. The important thing is that it is done and I can move on. So now I have this block with a hole through it, have test fitted the shaft and bearings and am ready to move on to the throttle bores, and once I have determined the spacing I can cut those. They will be fitted with trumpets going through the body and those in turn will house the butterflies. Then the body will get the outside contoured and an o-ring groove to mate to the body of the scoop and other details. As it gets closer to being finished it will get more interesting to look at and I'll be sure to post photos.

In the meantime the stock came in for the serpentine idler pulleys and I have some recycled bearings that will work very well for those. So after I have accurized the 3 jaw chuck for the lathe I can get started on those as well. Because they are back side idlers they will be simple pieces, requiring only concentricity and accuracy in the bearing bores.

Jim

Awesome Jim, keep getting all those small details done, before long we will all see a youtube video of your first start up! I can't wait to see and hear your fire breathing 340 on video.

"Yes" I can appreciate tight tolerances, that's where our wifes can help with small hands... to get that damn bolt in there so we can tighen it up. The BFH does work for last alternative :-).... My hands are big enough, that everything needed to go together in a certain way, to reach those 2 or 3 very hard unabtainable bolts. Specialty tools can be made.

Jim, it is close in there! Any concerns about the closeness of the back of the compressor to the header heat-wise?

A little Phil. The discharge line will have to have a "U" bend in it to go up and around the compressor and can be hard-line until it gets forward of the drive belt. I'll try first to find a hose with that end. The line from the condenser to the evaporator can be down on the frame rail, and that leaves the suction line which will have to go straight back to the firewall over the header. For that one I do have a new OEM hose with heat shield and insulation and I think a section of that will work pretty well although I'm also considering running it inside a stainless tube. I have some time to think about it. That is the line most likely to pick up heat.

Well, the stock for the pulleys came in but I'm not quite ready to start on those yet. I have finished giving the lathe a tune up but I'm working on the trumpets for the throttle body instead. My 3 jaw chuck had some runout so I mounted the 4-jaw, centered up a short piece of 2" chromed hydraulic cylinder piston rod that I had lying around and then clamped the 3-jaw to the end of it. That let me true up the mounting surfaces on the back and then I re-cut the backing plate to match. After all that, when I re-mounted the 3-jaw the runout was between 1/2 and 1 thousandth and that's about as good as it gets for an older machine with a cheap chuck.

That means that for most work I'll be able to remove the part and re-position it without losing my centerline, which is a big plus in lathe work, and it is certainly close enough for things like pulleys and trumpets.

So I parted off the blanks for the trumpets, about twice the finished length. Now I can swap the 3 parts in and out for roughing, finish, bore cuts, tapers and chamfers and get near perfect uniformity between the three. In fact, I can leave the finish cut on the OD until after I have cut and bored the mating holes in the throttle body block, and get just the fit I am looking for, then part them off and finish the inlet ends. (it is sort of important to map out the steps in advance) Once I get to that point it'll be a good time for pictures.

In the meantime I'll be thinking about the pulleys, and how I'm going to hold them while cutting the pulley grooves.

Jim

Thought I'd post some more bling:



Those are 2-1/2" throttle bores, the shaft is 7/16. The trumpets will get sunk into the block and then all rounded, smoothed and polished with brass butterflies and a stainless or aluminum actuator arm depending on what materials I have on hand. Next step, bore the holes for them, precisely to size and precisely 3.000" apart.

Doc

Looking good Jim, the racoons would be proud of you.

[www.youtube.com]

New sig video for ya, Doc



Edited 2 time(s). Last edit at 01/27/2012 09:53AM by Dan B.

"Wow" .... 2.5x 3 = 7.5" of airflow entry. Dang that's 190.5 mm throttle body there. I'm running a small tiny weeny 90mm throttle body. That is going to be some serious airflow. How much do you think your intake is going to flow with your calculations? Or where do you think your bottle neck will be? Are you going to install an IAC sensor in the throttle body?

Get the "buffing blinging" badaxx coon holes bored out! Can't wait to hear this 340 run!

Looks & Sounds the T/B will flow more than either the intake,heads or exhaust could flow. Just a little extra capacity if needed? Maybe you can use this T/B on the Roadmaster with some to spare :).

Naw, check your area calcs, it's a mere 110mm (4-11/16"), slightly reduced by the shaft and blade and some minor internal restrictions. Not that that matters when you have a roots type blower sucking air through it. I didn't want to choke off the engine any more than I had to. ;-)

The bottle neck? Probably the valves and cam, most likely on the exhaust side.

Doc

The IAC is mounted on the bottom of the scoop behind the throttle body, nicely tucked out of the way. Since it is upstream of the air filter all it needs is an inlet screen. The TPS will be mounted on the bellcrank below the throttle body for that clean look.



Edited 1 time(s). Last edit at 01/27/2012 05:31PM by BlownMGB-V8.

I think the "bottle neck" will be Jim's sphincter Calvin ;-)

That's some pretty fine machine work there Jim.
And it's soooo shiny.......must .......look ....away.
Cheers
Fred

OK brother Racoons! Look Away! Look away from the light!









Now I have to buy more tooling before I can continue, like a pair of horizontal/vertical indexers so I can slot and drill the shaft. And since I'm a cheap @#$%& it's ebay shopping for me and may take awhile.

Jim