340 upgrade

[BlownMGB-V8]

The intake blocks continue to lose weight:







Jim

[74ls1tr6]

Looking real good Jim! The machining is awesome looking "Custom work". What lbs injectors are you using for your 340? The X will be another water passage?

Would like to see this in the flesh when it is running for sure!

Calvin

[BlownMGB-V8]

Calvin, you'll notice that in these photos the x's are gone:





They marked the locations where I wanted to make sure I didn't accidentally cut water jacket ports. Not a particularly great place for a temp sensor or heater line either so they will be left blank.

The runners are now done as you can see. the 3-4 and 5-6 pairs will get a short divider wall between each set of openings since they are together in the induction order, which will go up to just under the intercooler core. Next will be the thermostat housing and some port work to match the runners. By then maybe I'll have the aluminum plate for the sides. When finished it will just look like a rectangular box under the blower.

Jim

[BlownMGB-V8]

OK kiddos, here we go! What you see here is an evaporator core out of a BMW. The fin area is 8 x 13 x 2-3/4" thick. Word is this unit has a 1-1/2 to 2 ton cooling capacity.



With a 1" plenum above and below the core, the intercooler enclosure is 4-3/4" high. This might cause the blower to stick through the hood a little. An Enderlie style scoop/throttle body will be added to the top of course.



The high pressure side has an octopus rig that feeds the entire first row of tubes independently for maximum effectiveness. Should the first row be on the top or the bottom? Still don't know the answer to that one.



The box will be a prominent feature, but will be flanked by the injectors and rails and preceded by the thermostat housing. Ignition will be via crank trigger as before, but I see no need this time around for a cam position indicator so the appearance will be a little cleaner. Port matching work is finished. Not perfect, but with pressure to encourage flow it doesn't have to be. Welding will begin once I have a better helmet. Pressure ports and temp sensors will be incorporated both above and below the intercooler core. I expect to see a pressure drop in the 1-2psi range across the core and will compensate for that. I'm hoping to see something close to a 10 degree temperature drop. We'll see how that turns out.

Jim

[BlownMGB-V8]

I've hit a snag. Maybe someone here can make a suggestion that might help. I decided to tack the runners to the intake wedges and I've found that EVERY ONE of my tack welds cracks straight across the center of the weld puddle as the puddle solidifies. I'm mystified. Nothing is moving around, the alloys are 6063-T52 and 6061-T6511 so weldability should be as good as it gets in an aluminum alloy I'd think, yet every weld cracks. I've not been using filler rod yet so it's just the base metal. Running straight argon gas at 15-25 cfm and creating weld puddles 1/4-3/8" diameter and up to 1/8" deep. Anybody have an idea why this might be happening?

Jim







Here's how the ports came out. Kind of a sharp bend on the short side radius but it couldn't be helped:

[Jim Stabe]

Are the pieces bolted down when you weld them? If so the parts expand as you put heat into them to weld and then when the weld solidifies and the metal is still hot, the parts try to shrink back to their original size and pulls the weld apart. You need to weld the assembly with the ports unrestrained and then machine the completed welded assembly to fit the block and heads.

[BlownMGB-V8]

Jim, the only parts bolted down are the  wedges, the runners are sitting loosely in place. But I think you might be on the right track there. Also maybe I'm not putting enough heat into it and/or cleaning well enough before welding. I will try again a little later today after I get a new stainless wire brush and a 1/8" electrode collet. Been using 3/32 which seems a bit light. I can't see anything moving but in every case the weld cracks just as the metal solidifies. Maybe not enough penetration. I'll cut a couple of practice pieces and experiment a bit.

Jim

[BlownMGB-V8]

Looks like I found the answer. From the ESAB site:

"We should start by considering the crack sensitivity of the 6xxx series base material.  The aluminum/magnesium/silicon base alloys (6xxx series) are highly crack sensitive because they contain approximately 1.0% Magnesium Silicide (Mg2Si), which falls close to the peak of the solidification crack sensitivity curve (Fig 1 at Al-Mg2Si curve).  The Mg2Si content of these materials is the primary reason that there are no 6xxx series filler alloys made. The cracking tendency of these alloys is lowered to acceptable levels during arc welding by the dilution of the weld pool with excess magnesium (by use of the 5xxx series Al-Mg filler alloys) or excess silicon (by use of the 4xxx series Al-Si filler alloys).  When we TIG (GTAW) weld on thin material, it is often possible to produce a weld, particularly on corner joints, by melting both edges of the base material together without adding filler material.  In the majority of arc welding applications with this base material, we must add filler material if we want to have consistently crack free welds.  A possible exception would be counteracting the cracking mechanism by maintaining a compressive force on the parts during the welding operation, which requires specialized fabrication techniques and considerations.  This method is seldom used."

He goes on to say that best practice is to use generous fillets so that filler rod is required to make the welds, thereby diluting either the Si or Mg in the base metal to reduce crack sensitivity. Guess you learn something new every day, huh? I haven't tried it yet but I suspect this will cure the problems I've been having. Here's the link if anyone wants to see the graphs:

http://www.esabna.com/us/en/education/knowledge/qa/Cracking-Problems-with-6xxx-series-base-alloys.cfm

Going to the Alcotec alloy selection chart:

http://www.alcotec.com/us/en/support/Alloy-Selection-Chart.cfm

it appears that for joining 6061 to 6063 the best choices for this application would be 4043, 4047, or possibly 4643 with "A" ratings for weldability and sustained service temperatures over 150* and a "B" rating for ductility.

Jim

[BlownMGB-V8]

Voila! Tried it using the 4043 filler rod and it worked just fine!



So I proceeded to weld up the top



and then the bottom.



Next the sides of the water passage, then the #1 runner and the rest of the bottom. That will be sealed up completely.

Now this points out something we all should remember. As the old saying goes, "There ain't nobody so dumb they can't learn something." Well, except maybe some who think they already have it all figured out, but that wouldn't be anyone here. So not too bad for an old farm boy, if I do say so myself.

Jim

[BlownMGB-V8]

The manifold base is now complete except for the thermostat housing and bypass fitting. It went together pretty easily, and I'm happy with the results. It did warp, so I made use of the shop press to straighten it back out (try that with a cast intake!) and was able to get it within about .010" or less total run-out front to back. I can live with that, no problem, and after the IC housing and blower mount are attached I will mill the excess weld bead from the flanges and take a light clean-up cut there and perhaps at the blower mount as well.  I now need to purchase more parts. The welds aren't as clean as you see on commercial parts but I'm getting better as I go and think I'll be able to do a reasonably cosmetic job on the ones that will show. Almost all of these will be hidden, either inside the box or under the intake so won't affect the finished appearance.

Jim

[Citron]

Jim,

Looks really good to me.  Not that I know much about what you are doing.  You know me, a bolt turner.
I saw on a nother site that a man near DC has some of those T50 trans you run.  I go near there when going to see my son in CT and could pick up one (or more) if you need.

Steve

[Jim Stabe]

Good to see you solved the problem, the internet is a wonderful thing.

Jim

[BlownMGB-V8]

Thanks Steve, but I'm not going back to the T-50, it isn't strong enough. Everything OK in Ct?
I was wondering if you might be able to make the trip out to Pete's the weekend of the 14th? (Nov)

I'm on hold waiting on parts but I might give you a call to talk about air conditioning stuff.

Jim

[MG four six eight]

Looking good Jim! I was going to suggest using filler rod, but I see you already figured it out! Are you going to run Freon through that inter-cooler core. That would really cool the intake air charge down. Those intake runners combined with boost and larger displacement, should give you LOTS of low end power. :-)

Bill

[BlownMGB-V8]

Thanks Bill. That's what I'm thinking, you just about can't have too much bottom end grunt. Even with the blown 215 I always wanted more. This should do quite nicely but still breathe well enough to approach 7 grand I'm thinking.

Freon, well yes sort of. I'm thinking more along the lines of propane actually. Yes I know it's flammable, about equivalent to gasoline. Certainly don't want any leaks. But it's an excellent refrigerant and not restricted in any way. Considering that some of the newer and highly touted r134 and r12 replacements are propane based perhaps it's not a bad choice, plus if it gets into the intake it won't create engine problems or turn to poison coming out the exhaust. That's a real consideration on this car, what with the side pipes and all.

But yes, that's the plan. I have a 2-1/2 ton expansion valve on order, that was the largest one carried by 4 seasons. Considering the excess heat of the intake charge that core should handle it. Then I need an appropriately sized compressor. I'm presently looking at the Sanden SD7H15 which has displacements up around 170 cu.in. That should be in the ballpark, obviously the more fluid I can crank through it the better it will cool, provided the condenser is up to the task. What I really need is a chart of A/C compressor displacements. That info is proving hard to mine.

The condenser should be relatively easy since I plan on a radiator somewhat similar to the one we have put on the MGB-Roadmaster and that gives me a very large core area to work with. Then the last critical component is going to be a solenoid valve positioned at the end of the high pressure line to the evaporator. With two of these tied to a relay in OR fashion, the pump will power the intercooler or the evaporator for cabin air. Another simple switch could allow both to be run at the same time but at shared capacity, seems I've heard of a system that might be somewhat similar being used in chebby suburbans for front and rear air systems. (Maybe I should be looking at those compressors too.)

So that's the plan anyway. I can probably set up an output from the Megasquirt to switch on the intercooler any time it's going to be needed. My A/C buddies have some doubts about it, so I'll definitely need to complete the instrumentation package this time and log the results, but with so much to do it'll be hard to get it all done by myself. Anyway, I think it will be effective but just how effective is the real question.

So, waiting on the TXV (thermostatic expansion valve) and a radiator hose neck for the intake. I've begun cutting the parts for the box but can't finish until the TXV gets here. Time to find a solenoid valve as well.

Jim

[BlownMGB-V8]

Oops, miscue there on the displacement. Obviously 170 cu.in. couldn't be right and it isn't, cc's is more like it. So, the big Sanden compressor is right around 10 cu. in. displacement, or using the numbers from the Sanden site, 154.7cc or 9.5 cu.in. By contrast, the Harrison R4 which is short, fat, and should fit more easily in front of the cylinder head, is 10 cu.in. or slightly larger. Perhaps I need to start a new thread.

Jim

[BlownMGB-V8]

Been working on the shop equipment again so that's slowed things down a bit, but I will soon be set up for coolant and that's an important improvement. Anyway the other day I had a little trouble pulling the damper back off the 340 so I smacked it with a mallet and the inertia ring moved. Can't have that, now can we? Doing a little research I found that fluid dampers are all the rage but nobody seems to make them for Buicks, and if I could find them prices are pretty stratospheric. Heck the TA-Performance hot shot dampers are around 4 large. So I got to looking around and found this little jewel on ebay:


http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=290355688580&ssPageName=ADME:X:AAQ:MOTORS:1123

The neat thing about this one, aside from the fact that it bolts to the hub, is that it has a poly-v pulley machined into the outer edge. Well, it has 7 ribs and I need 8, but there is room to cut the next one and I have the equipment to do it. So I bought it. Should get here about the first of the week. Most likely I'll have to make an adapter to match it to the hub of the old damper (minus the inertia ring and rubber gasket) and I'll also probably have to machine away a bunch of the weight of that adapter to match the old external balance weight, and then I'll have to ship it to Dale for a proper balance match. But it will solve two problems at once. A good reliable high performance damper and a drive pulley for the blower. Which I really have to have before I can position the blower on the intake. So for my next trick, (nuthin' up my sleeve...) I need to cobble up a rig to match static balance to the old damper so I can get it close. Stay tuned, boys an' girls!

Jim

[BlownMGB-V8]

Here we have the new fluid damper with the hub removed, alongside the stock damper. A couple of things might catch your eye. First, there is no way the hub that came with it can be made to work on the Buick engine, and second, there is a serious amount of weight on the Buick damper. (Dale Spooner informed me that it is a 28 oz bobweight) Of that weight only part is incorporated into the stock Buick hub and the rest will have to be supplied by a hub adapter which I will have to make. Secondly, there is more than enough room to cut another groove to enable the use of an 8 groove belt. I have ground the tool for that, determined the spacing at .140" and would have cut it already but I wasn't happy with the run-out on my initial setup. I may try to turn it after the new adapter is in place. But before I can start on the adapter I have to mock up the A/C compressor. Because I am going to try to use the stock compressor mount, that will determine where the belt has to run and the other pulleys will have to be juggled to match it. More later...

Jim

[BlownMGB-V8]

Not as glamorous as making an intake, but I began work on the compressor pulley yesterday.



But, after cutting down to the root of the v-belt groove I discovered that I was into the cement used to bed in the friction surface and this pulley is now scrap.



So I need some help. A6 compressors came with different diameter pulleys and I need the largest one I can find. Something where the root of the v-belt groove is close to the diameter of the clutch would be perfect. GM used these on everything for quite a few years as did other manufacturers including Ford, and the displacement/engine revolution was varied by belt drive ratio. So odd as it might sound, a small car or pickup should have a larger pulley.

I found something else interesting in the form of an aftermarket A6 replacement compressor, the Pro6ten made by Old Air Products.  http://www.import-car.com/Article/42966/old_air_products_offers_boltin_direct_replacement_for_the_gm_frigidareharrison_a6_compressor.aspx

Said to be 52% lighter than the old A6, this 10 piston replacement makes the expected claims of efficiency, smoothness, etc. But my question of what the displacement is remains so far unanswered and ditto for the poly-v drive pulley. And it's expensive.

So can anyone help out with the pulley?

Jim

[Dan B]

Jim,

Specifically, what is it you are looking for?  Is this the compressor pulley or something else?  What kind of diameter and width are you looking for?

[BlownMGB-V8]

This is the Harrison/Frigidaire A6 compressor, a common sight on GM cars from the 50's into the 80's:


Next removal of the clutch:


And finally the part I am looking for, the pulley:


The sheave of the pulley came in different diameters for different cars, some small for higher speed and more output, and some large to slow the compressor down. That's how they got away with using one pump for all applications. I need a big one.

Jim

[BlownMGB-V8]

OK I got it. It's a tractor application which makes sense. Single seat cabin, 2500 rpm operating speed, need to slow that pump down a lot. The pulley is about 6-3/4" for a 7/16" belt so there should be plenty of meat above the clutch diameter and a smooth cut across at that point should not be a problem. There is plenty of room below that for the 8 belt grooves. So now to just find one. Guess I'll be visiting the local tractor shops.

Jim

[BlownMGB-V8]

Been a lot going on since I last posted. First off, the A/C based IC system has real questionable viability. No real surprise there since Ford had to use a thermal accumulator to make theirs work. The problem is that the heat of evaporation of freon is very low, something like 1/20th of water's. Various other fluids were investigated in terms of phase change temperature, latent heat, freezing point and compatibility with the system materials and after considerable calculation and testing it has been decided that plain old gasoline at atmospheric pressure and 2 gpm flow through the evaporator is the best choice. This means that a good fuel pump will handle circulation and no draw-down and purging will be necessary. OK, that's the good news. Calculations are being checked as we speak but it looks like a workable plan and other details of the system will be described later. Cabin air will be a separate system.

Next, the damper has to be mounted before anything else can be done. So, in the following photo you'll see a balancing tool I made up from bits lying around the shop.



Assembled it looks like this:



But needs more room to rotate completely so:



Here it's mounted in the bench vise. It turns out to be very sensitive and will detect less than 1/8 turn of the screw and very minute angular changes so once dialed in I marked the keyway, drilled and inserted a pin to lock the position. The slight position error that resulted meant that I had to screw a couple of bolts into the damper hub to get back to center. I dare say that when I send the finished part to Dale for checking it should be within grams of proper balance.

So next I'll knock off the inertia ring and begin to turn the adapter out of the large blank of 1018 steel seen above the stock damper in the first shot. That's over $80 worth of round stock, just one example of why custom parts cost so much. Most of it will be whittled away to make an adaptor that will precisely fit the fluid damper to the original hub, and it will also have a ring of holes drilled in the rim of it to trigger the Ford EDIS ignition system and Megasquirt EFI. Quite a bit of work before we're at that point though.

Jim

[BlownMGB-V8]

I got the blank chucked up in the lathe, rough turned, faced, drilled, and cut one counterbore on the back side for the trigger ring. Tomorrow I will try to do some more work on it, the bore for the damper hub and the one for the pilot ring on the face of the hub. First I need to measure the amount of offset weight that is needed. This can be done by placing weights on the threaded rod at the correct distance from center until it is balanced (with the outer balance ring now removed) and then finding the mass of that weight in a common sized material such as round stock. That will tell me how much material will have to be removed to balance the adapter, which in turn will tell me how much material I will have to leave in an area where it can be selectively machined away. It would be far too easy at this point to leave excess metal in the part, but this increases rotating mass and reduces the responsiveness of the engine. Conversely it would make it idle smoother but I'm not after a smooth idle. So light weight is the goal. When completed the adapter should be as light as I can make it and still do it's job. After the bores are cut and all surfaces turned to finish size I will flip the part and turn the pilot for the fluid damper, at which point the lathe work should be done. Then comes drilling the hole patterns for the damper and hub, then trigger holes and balance/lightening holes, and final assembly and fitting. Then it goes to Dale for a final balance. By then I hope to have the pump for the IC ordered and can get back to welding.

Jim

[BlownMGB-V8]

The back side of the adapter ring is done.





Jim