340 upgrade

BlownMGB-V8 · July 12, 2017, 09:19:51 PM

So I got insurance on the car today and went for a couple of short drives down the street. Still have start-up and warm-up tuning to do and there's a squeak I need to find, but initial results are promising. It's got a lot of power and sounds awesome, the blower is putting out about 5psi which is what I was expecting.

I'll try to shoot a video next time I have family in town, probably the weekend of the Dayton meet. By then hopefully I'll have most of the shake-down done.

I haven't given up on the 8 speed, I recently learned that the TCM used in the 2014 and 2015 Cadillac CTS line might do the trick. Provided I can acquire a pin-out for the TCM connector and perhaps a schematic of the wiring for it. Not the easiest task. In the meantime the T5 will do nicely. I ended up using a S10 clutch fork and Isuzu slave cylinder and think it went together pretty good, not perfect but well enough.

Jim

Jim Stabe · July 12, 2017, 10:55:55 PM

Take that thing out and scare the crap out of the cameraman in the right seat. Hopefully, he/she will keep the video going so we can see it in action.

MG four six eight · July 13, 2017, 12:04:55 AM

Jim,

I can probably get the pin out and schematics for you. Due to copy right restrictions, most likely I will have to print them out and snail mail them to you though.

Bill

BlownMGB-V8 · July 13, 2017, 01:20:47 AM

That'd be great Bill!
I'll PM you.

Jim

mgb260 · July 13, 2017, 01:17:16 PM

Jim, Congrats! Take it easy starting out with the low gear first in that T5. You can probably start out in second.

BlownMGB-V8 · July 13, 2017, 03:37:01 PM

... or 3rd. Or 4th.

Starting to drive it around a bit. Not happy with off-idle, I think I need to change the linkage geometry to get more movement initially rather than less, the way it is now. Feels sluggish but it really isn't, just not getting as much gas as the foot thinks it is. Guessed wrong there. It should be pretty easy to change. Mid throttle it has a lot of power. Also I think my off-idle tune needs some work.

Interestingly enough, with the 3.54 gears and the 25.7" tall tires, 1st gear is usable. Then around half throttle in 2nd breaks the tires loose. So I have some work to do with that.

In time I hope to have something I will enjoy driving but it may be awhile before I get there. Not quite like I can just pick right up where I left off with the 215. But the raw material is there, now I just have to refine it. There are a number of quibbles. Can't swear it'll be ready for Dayton but perhaps, and Townsend should be very possible.

Jim

rficalora · August 17, 2017, 10:00:04 AM

Hey Jim, you drove your car to a recent event, right? How'd it feel to have it back on the road?

BlownMGB-V8 · August 17, 2017, 10:56:21 AM

Oh it was glorious! Driving a high powered MGB convertible in simply incomparable. (And I pity you GT drivers

)

Seriously though, I'm working my way through the shake-down and there is still quite a bit to do. But, the important parts are mostly done. Interesting to compare the roadster to the MG-Roadmaster though. Where the Roadmaster is infinitely civilized, the roadster is just something of a rampaging lunatic. Very controllable, but perfectly happy to simply go off at any instant. Once I get the rough edges ironed out I think I'm really going to like it a lot. Of course that could take awhile...

Jim

BlownMGB-V8 · October 25, 2017, 08:10:15 PM

Today I re-torqued the heads to 75 ft/lbs (It has studs and an iron block), and did some work on the belt idler pulleys. They didn't track quite right so I cut the side flanges off and cut a little bit of a crown in them. Looks like that did the trick, too bad I didn't think of it sooner, the belts are about $80 apeace.

I've been working on the tune and now have the hot idle down to 1100 rpm which sounds pretty reasonable, at least for now. The engine will recover from dips down to as little as 300-400rpm so I think it should be able to idle lower but I'm fighting a low speed oscillation. I think I've done about as much as I can with the timing and mixture but who knows? Best to start driving it I think.

I'd been having some trouble with cooling but think I have that sorted out now. The surge tank wasn't quite big enough apparently so I added a coolant recovery bottle as well, capped them both with 14psi pressure caps, making system pressure 28psi, and now the recovery bottle doesn't even get hot but it does build pressure. Temp is holding at 190, with one fan running. So far so good. I've run across a real good coolant system sealant, which we used on the Roadmaster to fix that small leak at the timing cover so I'm going to get some of that and put in it since I've been having a little difficulty with getting the copper head gaskets to seal up the water jacket. (hence the re-torque)

I had to disable my hydraulics on the wing for the time being. It seems I have fluid crossing over so either I have a bad piston seal somewhere or a leak between the reservoirs. More testing required. I locked the wing so I can drive it.

I think I'll wait to start it again until I have the sealant added.

Jim

Moderator · November 16, 2017, 10:12:38 AM

"capped them both with 14psi pressure caps, making system pressure 28psi"

huh?

MGBV8 · November 16, 2017, 11:00:02 AM

I meant to revisit this, Curtis, cause I didn't follow that either.

I wouldn't think Dalton's Law applies in Jim's situation.

BlownMGB-V8 · November 16, 2017, 11:22:25 AM

The two caps are in series so the pressure adds.

The first surge tank overflow is after the pressure cap which holds 14psi.
The second, the coolant recovery bottle also has a 14 psi pressure cap which adds to system pressure.

So the total is 28psi. Dlaton's law notwithstanding.

The last week I've been swapping transmissions. Removed the non-wc T5 and installed a Tremec TKO-425. OK that's probably not the right number but it is the torque rating. It was the predecessor to the TKO-500. Larger input shaft with 26 splines, larger output shaft with 31 splines, derived from a Ford version but built to fit GM applications. There were a few significant differences. First of course was the need for a larger slip yoke and a larger clutch disc. Which also meant a conversion u-joint to match my driveshaft. Overall length was about 1/2" shorter so that was fine. The speedometer drive required a special adapter which I then had to modify further to match my Jaguar speedometer sender unit but I much prefer the new angle of the speedo drive which is pointed more downwards making it easier to fit in the tunnel.

The fit into the bellhousing was tighter than I would have liked, and the shifter came out a bit forwards and to the right, requiring some light trimming and a new cover plate. The shifter itself attaches with 2 bolts and the stub sticks up above the tunnel about a half inch. I did not have to touch the transmission tunnel and have probably a half inch of clearance under the seam which is as original. The crossmember did not quite line up and the forward edge had to be trimmed and reinforced. Another inch of setback would have helped there and my engine position is farther forward than most. It has a 3.27 1st gear and 0.68 OD I believe. I won't get to drive it for a few days more though as I'm finishing up the shifter and I have the car on the lift cutting the passenger's side rocker in an attempt to straighten out the bend in the body. But it should be an improvement.

Jim

MGBV8 · November 16, 2017, 05:44:51 PM

Same pilot bushing?

BlownMGB-V8 · November 17, 2017, 01:34:39 PM

Yeah that's the same. So here's the scoop on using the S-10 clutch fork, a photo link from Rockauto is below. As you can see it has a significant bend at one end. If you use it with a 10-1/2" pressure plate that end will hit the hat and you'll need a pedal stop, plus it will not give enough clearance to allow for clutch wear.

http://www.rockauto.com/info/797/LK_LF9836_Fro__ra_p.jpg

So the steps to make it usable follow. First, with a hydraulic press, straighten the bend

Then straighten the sides

Then flatten the dimple by pressing it flat then find it's new location, mark it and press in a new dimple

Continued:

BlownMGB-V8 · November 17, 2017, 01:40:56 PM

I also straightened the body of the fork so it would lay flatter against the transmission for more travel, and straightened the bend at the ball socket to align it more correctly with the ball. (on the other end)

Contimued:

BlownMGB-V8 · November 17, 2017, 01:44:23 PM

You can see here that there is at least 1/2" of allowable travel before the yoke hits the transmission.

Continued:

BlownMGB-V8 · November 17, 2017, 01:50:02 PM

The slave is an Isuzu part available for $40 from Amazon.
Dorman CS360032 Clutch Slave Cylinder

I used banjo fittings and put a hose on the bleeder that reaches the reservoir for recirculation bleeding, works a treat. I may have had to re-tap the bleeder port to a larger size, not sure on that. The push rod that came with it was exactly the right length. Bore is 3/4" and stroke is 2".

And that's all I have for you guys at the moment. Should have it completed today or tomorrow.

Jim

BlownMGB-V8 · April 20, 2018, 11:55:27 PM

So I've been testing and tuning and trying to use this much delayed spring as an excuse to get the car ready to drive. There was (and may still be) an oscillation at any idle below 1200rpm that I've spent countless hours trying to resolve yet it has resisted all attempts to date including extensive remapping of all injection and ignition parameters. The most recent datalogs show a steady idle and then it will drop into oscillation. The way it begins is that for no presently discernable reason the revs will climb then drop. George Van Horn has looked at the datalogs with me and we have drawn a complete blank on why that happens so at his suggestion I have reloaded the firmware. But I think I already tried that way back at the beginning so it may not change a thing. Tomorrow's test drive should tell.

But it is plenty drivable and the good news is that I've finally begun to use Autotune and get some usable results. When they first came out with that it was kinda buggy and didn't work very well. Mind you this was, what? 15 years ago maybe? I decided at that time that I could tune the VE map as well as I could the AFR table, and after getting used to that saw no real need to try it again. Anyway now it works pretty good. Turn it on for awhile, push the button to smooth the map a time or two and repeat, tweak the outlying areas and do it again. I'm happy with the results so far.

Finally ordered a new rear bumper. One of the old overiders was touching my new gas cap, couldn't have that. So I cut those off and installed a set of LED bolts for the tag lights. But man, that bare bumper is sure gonna uglify the car til the new one comes in what with the dents and scratches that were covered up, as if it wasn't already ugly enough anyway.

I did Glen's zerk fitting mod on my door hinges and have swapped out the passenger's side, which meant the door had to come apart of course and this was a good excuse to refinish the door panels, caps and pockets. I just finished up one side and have the other yet to go but it really spruces things up inside the car. That got me thinking about speakers so I ordered a new set of 6 x 9's. I used to have early Altec-Lansing Voice of the Highway 4A 6 x 9's mounted on the doors below the window cranks. I knew they were extremely good but did not realize quite how special until the long fruitless search for adequate replacements. But, maybe these will come close: Morel Maxima Ultra. They are supposed to be pretty good, we will see.

There's a local car show tomorrow. So, the first actual hand wash in many years in the morning and a stop by in the afternoon. With the top down. YAY!

Jim

Jim Stabe · April 21, 2018, 02:16:25 AM

Pictures coming I hope. Have you had a chance to really stomp on it yet?

BlownMGB-V8 · April 21, 2018, 02:24:25 AM

Not really hard but I've gotten into it enough to know the power is there. However it seems I may have been a little conservative on my valve spring pressure so won't be wringing it out until that is upgraded. Meantime I'll be keeping it under about 4500rpm. Not that this creates a problem you understand. It's a very frisky engine.

Photos... yeah, that'd be a good idea.

Jim

Jim Stabe · April 21, 2018, 03:59:03 PM

"Frisky" - Great description, I'll have to remember that

BlownMGB-V8 · April 21, 2018, 10:31:51 PM

I'm sure you've experienced much the same thing.

You know, I used to say that at 300hp you could do anything with the MGB that you wanted to. And that was true enough. Now it's just, well, more so.

I took it to a local car show today, that was fun. Didn't stay very long, just enough to wander through once or twice and answer a few questions but I had a good time. The idle oscillation though? Yeah I've still got that. Maybe it'll go away when I switch to MS3. I also have a plan in the works to remove the intercooler. Don't need it at my level of boost and it'll drop the inlet 3-4", vastly improving my sightlines. That will probably happen over the winter. Maybe I'll add the IC condenser to my A/C system and boost it's efficiency (once it's finished that is). Seems like a good choice since it is already installed. Anyway, if the oscillation is somehow related to induction volume that should change it for the better.

Jim

MG four six eight · April 24, 2018, 11:37:45 PM

Jim,

What are you running for air/fuel ratio at idle? The reason I ask, is because I have to run a slightly richer fuel mixture at idle.
I tried and tried to get it to idle at 14.7 to 1 without it surging. Finally I resigned to just giving the motor what it wants and it idles nice and smooth in the 13.2 to 13.5 to 1 range. It also produces the highest vacuum reading at idle with a 13ish to 1 fuel mixture as well.
At cruising speeds I can get away with a leaner mixture no prob. However I'm thinking that the motor likes a slightly richer mixture at idle due to the parasitic draw from rotating the supercharger.

Bill

BlownMGB-V8 · April 25, 2018, 10:15:01 AM

Thanks Bill, I think just about any engine is going to need a little richer mixture at idle. In fact I'm not yet down to 14:1 anywhere on the map just yet. So that's not the problem.

Jim

BlownMGB-V8 · January 30, 2019, 12:18:59 PM

I thought an update might be a good idea. The car was running pretty good and I had it out on a couple of medium long runs mostly without incident. Mostly I say because at the very end of the trip back from Townsend, about 3 miles from home the engine went off-song and began running pig rich. I nursed it home and parked it. since then diagnostics have shown that leak-down is as perfect as it can ever get and fuel pressure is as expected. the problem appears to be in the MS controller.

That's it, I'm done. I've had just about enough of the MS amateur hour. I know a lot of you have had nothing but good luck with MS and I salute you, but it hasn't been so smooth for me. After more than two decades with these products, numerous failures and even abandonment issues what I want above all else is reliability. Something that they just don't have I'm afraid. Probably their top of the line fully assembled and sealed unit is better, but it also costs over $700. Sorry, count me out, there are now better options.

So I went out to the pick-n-pull. For $50 I bought a Gen III GM LS ECM with connectors and about 2 ft of wiring and it took all of 5 minutes to remove it. (The so-called 0411 ECM) For $32 I bought a reluctor ring from Summit to work with it. Pickups and sensors, connectors and such will be a couple hundred more, LS COP coils which I intended to add anyway will add another $150 or so. Some work will be required to adapt these pieces.

The 411 controller is of course at the top end in terms of hardware. Nothing to criticize. It has self-learning capability, COP, full sequential, fan control, fault tracking, and a host of other capabilities as you would expect from any major manufacturer's 2002 or later ECM. It can also be tuned using a laptop and flashed to save tunes. It appears to have been one of the first with all these capabilities and is considered probably the most desirable controller among hot rodders. Hopefully I've done my homework well enough. The reluctor is mounted with the small calibration hole under the pickup with #1 cylinder at TDC. A cam position sensor is required. Luckily I already have one in the engine. I hope to be back on the road by late spring. We will see.

Jim