TheSamba.com :: View topic

Tue Aug 01, 2006 7:31 pm

Again, I have an Empi case made by auto Linea.

case was 400 bucks, BUT came clearanced for stroker crank, bored for 94mm cylinders and full flowed. also included all the case hardware!

Everything I was able to check, checked out perfect! except the feed hole oil for the pump, was off about .070. Not much, certainly not enough to stop the motor from oiling and I have seen the brazilian AS-4! off as much or more. Certainly good enough for a stock motor.

Only beef I got is that they removed more then I would have when they clearanced it and it HEAVY!

Again, has not been cranked, might be a piece of crap, but I'm feeling pretty good about it so far.

Wed Aug 02, 2006 1:38 pm

kimosullivan wrote:
GeorgeL wrote: Is _anyone_ making a _correctly_ machined aluminum case? I've never heard of anyone putting together a motor based upon a aluminum case without major corrective machine work.

http://www.grupohubner.com.br/autolinea/04_produtos.html

I've got an Auto Linea case. It arrived ready for a stock 1600...

...I will say that the oill pump I have was 0.050" out of alignment with the oil galleys in case, but that was remedied by a 0.050" thick piece of aluminum and a hole saw to shim it out.

In other words, the answer to my question is "no."

I've heard this same response several times. Generally it goes "I have an aluminum case and it is perfect!" "Well, except that [insert name of machined surface] was [insert tolerance] off and I had to [insert corrective measure]."

The other thing is that most folks who make these assertions haven't actually run their aluminum-cased engine yet. Every example of a running aluminum-cased engine I have heard of has been a nightmare, even with the engine owner bending over backwards to try and justify their choice of the aluminum case.

I'm still waiting for someone to honestly say "I built my engine on an aluminum case and I've had no problems with it." When that finally happens I might consider using one.

Wed Aug 02, 2006 1:51 pm

well my options are as41 or alu............i would like a nice reliable engine for daily driving in the heat of tucson,az............but also kick some ass and make people respect the vws power!!

Wed Aug 02, 2006 3:04 pm

GeorgeL wrote: kimosullivan wrote:
...I will say that the oill pump I have was 0.050" out of alignment with the oil galleys in case, but that was remedied by a 0.050" thick piece of aluminum and a hole saw to shim it out.

In other words, the answer to my question is "no."

I've heard this same response several times. Generally it goes "I have an aluminum case and it is perfect!" "Well, except that [insert name of machined surface] was [insert tolerance] off and I had to [insert corrective measure]."

I would have shimmed the oil pump to align it with the case if it was as little as 0.010" out. I'm sure if I had a new oil pump instead of a thirty-five year old one, the alignment would have been better. Shimming was the least of things I had to do to the oil pump. It started as a 26mm manual, and I rebuilt into an autostick pump. Then the back of the pump body had to be spot faced to clear the aftermarket camshaft and gear. I can't blame the alignment problem on the crank case. These are the things one must deal with when building a custom motor.

Thu Aug 03, 2006 7:25 am

I have just completed assembling a 2276 Auto Linea aluminum case. I bought the case machined for 94 jugs and 82 stroke. The only machined holes in the thing that did not require extra work were the lifter bores. I even had to clean up the distributor drive hole. The casting grain itself looks very tight to me. It burred out clean. I am not sure I would not have the same issues with a new AS-41 case. I tend to be anal about clearences and smooth movement when rolling over by hand. The thing feels great at this point. It goes in my sand rail and will fire up this weekend.

Thu Aug 03, 2006 1:41 pm

kimosullivan wrote:

...and weld, drill, tap, and plug for full flow. These would all have to be done to a stock magnesium case anyway, and the welding was much easier on aluminum.

What are you welding for fullflow? Never heard that one before.

Thanks

Thu Aug 03, 2006 6:49 pm

if you have had a recently made AS-41 that needed no tweeking, your are lucky. Blueprinting a pump is NOT major machine work. I've NEVER had case made by anyone that the oil hole lined up perfectly.

The oil oil being off is Minor in my opinion, it would have NO effect on a stock motor.

Like I said, I'm building a 2332 with scat H beams, chevy journals, large 3/8 bolts. except for clearancing the cam, the crank and rods dropped in!!!

This the ONLY case I ever had that needed NO machine work! It came full flowed, stroker clearance and bored for 94's 400 bucks!!!

I would had over $500 in an AS-41 case, and the oil hole would have been off it it also, plus the pickup tube would be about to fall out!

GeorgeL wrote: kimosullivan wrote:
GeorgeL wrote: Is _anyone_ making a _correctly_ machined aluminum case? I've never heard of anyone putting together a motor based upon a aluminum case without major corrective machine work.

http://www.grupohubner.com.br/autolinea/04_produtos.html

I've got an Auto Linea case. It arrived ready for a stock 1600...

...I will say that the oill pump I have was 0.050" out of alignment with the oil galleys in case, but that was remedied by a 0.050" thick piece of aluminum and a hole saw to shim it out.

In other words, the answer to my question is "no."

I've heard this same response several times. Generally it goes "I have an aluminum case and it is perfect!" "Well, except that [insert name of machined surface] was [insert tolerance] off and I had to [insert corrective measure]."

The other thing is that most folks who make these assertions haven't actually run their aluminum-cased engine yet. Every example of a running aluminum-cased engine I have heard of has been a nightmare, even with the engine owner bending over backwards to try and justify their choice of the aluminum case.

I'm still waiting for someone to honestly say "I built my engine on an aluminum case and I've had no problems with it." When that finally happens I might consider using one.

Thu Aug 03, 2006 8:42 pm

a_67vdub wrote: What are you welding for fullflow? Never heard that one before.

The oil galley on the left side of the case at the top. First thing the oil pump feeds to. I've got an autostick pump to scavenge the turbocharger, so I can't run a pump cover with outlet. The rear of the oil galley has the plug removed first. Then the side of the galley is welded up to provide room for the oil line fittings to be drilled and tapped for 3/8" NPT. Inside the oil galley is drilled and tapped between the inlet and outlet holes for a 1/4" NPT pipe plug to force oil out of the case. The end of the galley is tapped for a 3/8" NPT plug to complete the setup. I guess you could get away with the outlet at the stock plug location and only drill one hole in the left side of the case. I put both holes on the side. There was an article in DB&HVWs about this a few years ago.

Sat Aug 12, 2006 11:04 am

I'm not even going to pretend that I know jack about which is better, just that I'm running an Empi aluminum case for about 2 years now in my daily driver - no problems / no leaks.

Seems I've seen alot of automotive applications with aluminum, and not much; if any (besides air-cooled VWs, and rim manfactuers) using magnesium. Why is that? I'm sure someone will enlighten me, and post what other motor makers are using magnesium...

Thought I had read somewhere about magnesium being cheaper during the war, and that the material of choice was actually aluminum - but it was in short supply. No?

Peace, Greg

Sat Aug 12, 2006 12:48 pm

68Bug-lite wrote: I'm not even going to pretend that I know jack about which is better, just that I'm running an Empi aluminum case for about 2 years now in my daily driver - no problems / no leaks.

Seems I've seen alot of automotive applications with aluminum, and not much; if any (besides air-cooled VWs, and rim manfactuers) using magnesium. Why is that? I'm sure someone will enlighten me, and post what other motor makers are using magnesium...

Thought I had read somewhere about magnesium being cheaper during the war, and that the material of choice was actually aluminum - but it was in short supply. No?

Magnesium is by far the less dense material, so if you are building aircraft or lightweight cars it is very attractive. I don't think that it had much to do with wartime shortages, as magnesium was also considered a strategic material for its aircraft and munitions applications.

However, you have to design for the material. Magnesium has a hexagonal close packed crystal structure, meaning it can be brittle and less capable of elastic deformation than other metals. Aluminum is cubic close packed, while iron is body centered cubic, both of which lead to more mallerability than magnesium. Thus, if you design in magnesium you have to make sure that the metal doesn't get subjected to stresses that cause it to deform beyond its modest elastic limit. Aluminum is more forgiving, which is why it is theoretically a better metal for high performance engine cases. Iron would be a good material too, but if you think the aluminum cases are heavy... :)

George

Sat Aug 12, 2006 4:22 pm

Kimo - Thanks for the explanation, it makes sense that if you can't take the oil out of the oil pump cover then you have to come up with something else.

I know one negative trait of the aluminum case is that it's sand cast instead of die cast. Does anybody know if the current AS41 case's are die cast or sand cast?

I think that the "construction methods" have as much to do with case longevity as material.

Mon Aug 14, 2006 9:51 pm

a_67vdub wrote: Kimo - Thanks for the explanation, it makes sense that if you can't take the oil out of the oil pump cover then you have to come up with something else.

I know one negative trait of the aluminum case is that it's sand cast instead of die cast. Does anybody know if the current AS41 case's are die cast or sand cast?

I think that the "construction methods" have as much to do with case longevity as material.

I just built a 2276 with a CB case. I didn't like all of the loose material from the sand casting process. I'm affraid that I didn't clean it good enough and ruined my motor.

I don't know what I'm going to use at this point. I might just go with T4's for my own enjoyment, or non-clearanced AS41 cases.

Tue Aug 15, 2006 10:30 am

My experience with the type 1 aluminum case.
I had one of the first ones that came into the states that i had actually found enough porosity to leak out of one of the main oil galleys into the motor. (found long before i did any work on the case) So i took it back and got one from the second batch that came into the states. only major problem was the oil pressure relief port not being finished up. That case ran for 4 years in race conditions.
One of the reasons i wanted to try and al case is to see how the center main journal would hold up. And after 4 years, it was still spot on. For me as a racer, it was important to hold the crank in place. BUT then i found a crack at the upper rear number one stud. Not sure what it could have been that caused that. 28+ lbs of boost? Maybe a touch of detonation? just getting old? (sharpie marker enhanced crack)

To me, the case is a disposable item. eventually i will have to change. So i was pretty happy with what i went through with the first generation of those cases.
Had a friend with an early generation case torch the rear main and take the dowel pin about 3/4 the way around the saddle. This WOULD have spread a mag case apart. but this case still measured round and not spread. that really amazed the _____ out of me.
I am now on a new CB aluminum raised roof case. NICE! One of the area's of conserned i had with my old case and were it was cracked is now filled in behind that area. It is just all around refined from early models.
Old case. hollow behind the insert

new case filled in.

HEAVY? yes. Is it for every one? No.
But i think for my race application, it fits perfect. And if it last another 4 years of nothign but racing, id be plenty happy. Had i used a mag case, its a good chance that the center main saddle would most likely been pounded out.

My conclusion: it has its place. By far, it doesnt fit all sinarios. but it is a choice. I certainly did not hesetate to run another al case.

Tue Aug 15, 2006 7:19 pm

I also have been using a alum case for over a year now, Yes I found some machining errors like the dowl pin in the rear saddle was drilled too deep as well as some other small things that were easily fixed; but I found that these problems were far out weighed by the pure strength of the case. I believe that this is a case that can be better then any mag case if it is put in the hands of the right builder....

Tue Aug 15, 2006 8:42 pm

GeorgeL wrote: Magnesium has a hexagonal close packed crystal structure, meaning it can be brittle and less capable of elastic deformation than other metals. Aluminum is cubic close packed, while iron is body centered cubic, both of which lead to more mallerability than magnesium. Thus, if you design in magnesium you have to make sure that the metal doesn't get subjected to stresses that cause it to deform beyond its modest elastic limit. Aluminum is more forgiving, which is why it is theoretically a better metal for high performance engine cases.

I hope there isn't an exam on this. :)

Wed Aug 16, 2006 3:08 pm

nemobuscaptain wrote: GeorgeL wrote: Magnesium has a hexagonal close packed crystal structure, meaning it can be brittle and less capable of elastic deformation than other metals. Aluminum is cubic close packed, while iron is body centered cubic, both of which lead to more mallerability than magnesium. Thus, if you design in magnesium you have to make sure that the metal doesn't get subjected to stresses that cause it to deform beyond its modest elastic limit. Aluminum is more forgiving, which is why it is theoretically a better metal for high performance engine cases.

I hope there isn't an exam on this. :)

Hey, I had to get _something_ out of that materials science class I took 30 (gad) years ago!

And, for those who want to know what to do with those pounded out magnesium cases, here's a guy that burns them in a big way (30 at a time, he says!)

http://www.burningart.com/meico/pyro/mag.html

Sat Aug 19, 2006 6:04 pm

Has anyone ever opened up the main bearing saddles and use steel sleeves for new saddles. Just a crazy idea.

Sun Aug 20, 2006 5:31 pm

Bad bug wrote: Has anyone ever opened up the main bearing saddles and use steel sleeves for new saddles. Just a crazy idea.

I've never heard of it, but I have no doubt that something like this will be done when the supply of new cases dries up. Impractical procedures become quite practical when the alternative is no engine at all.

George

Sun Aug 27, 2006 7:57 am

I am surprised none of the diehard traditionalists brought out the fact that one of the reasons besides light weight of the original engine material was that the mag case could be machined dry without using oil. It really sped up the production line doing it this way.

The VW was designed pre war with old Adolf breathing down there neck. Germany is a land locked country and had little or no oil resoruces of there own. I often ponder weather the small oil sump is also a result of this? Isn't one of the first performance upgrades to add a deep sump? Germany also did developement on synthetic oil durring that time.

The little air cooled engine was fine with the mag case but when they jumped to the 2liter and more power which = more heat they also changed case material to the aluminum alloy.

Just to repeat- It all depends on what you want to do with your choice.

Sun Aug 27, 2006 3:07 pm

EZGZ wrote: I am surprised none of the diehard traditionalists brought out the fact that one of the reasons besides light weight of the original engine material was that the mag case could be machined dry without using oil. It really sped up the production line doing it this way.

The VW was designed pre war with old Adolf breathing down there neck. Germany is a land locked country and had little or no oil resoruces of there own. I often ponder weather the small oil sump is also a result of this? Isn't one of the first performance upgrades to add a deep sump? Germany also did developement on synthetic oil durring that time.

I seem to remember the old B/W factory movies showing machining of the crankcases and transmission cases with coolant/lubricant spraying away. You might be able to machine magnesium without lubrication, but not as fast as a factory would want to do it!

The small sump was because the VW design was minimalist. It didn't need five quarts of oil, so why carry that much around and why use the space (and ground clearance) to house it?

"Common wisdom" is to add a deep sump for a high performance engine, but a lot of high performance engines work fine without one. The purpose of the deep sump is to keep the pickup in the oil while cornering.

George