UPDATED 12/21/09 & to all!

While the 917 is not strictly 914, it is historical info from the period & definitely original info. from the factory & race drivers of the day. And the pay-off for the link after this "shameless hook", is the info in the thread of how an Engineer from the Porsche Racing Department was able to make the lowly VW 1.7L 4 banger into a respectable "Porsche-bred" 90-100 hp 2L engine - when VW thought it was impossible to go any bigger & had been max'ed out at 1.8L (+/- 200% - recall it started in the 1930's VW as only about 900 cc).

See the videos at the link below, & also peruse the additional clips at the sidebar after viewing this one linked below, including those linking to racing 914/6's.....

<snipped>
If you like racing and the sounds of Porsches, you will love this video:


YouTube - Porsche 917
<end snip>

Enjoy! Courtesy of our local PCA-OCR membership chair!

Then read the lively discussion on the link between the 917 & 914-2.0 engines, of which even the "Master of 914 O&H" was not aware!

...Heck! - even I'm learning stuff I didn't know from others of you out there, which I always do!

I can't wait for Pat to see this thread...

Tom,

You're pushing Pat's buttons again. I can see him now......

Paul

Nope.....there's a connection between the 914-2.0 engine's design/engineering & the 917's - which these videos are about the factory history on the 917 & it's engineering.

I've been looking for the other link about it this afternoon, but my laptop has died & needs to go to Fujistu, & it has all my 914 info & bookmarks, etc. So I can't post the 2nd part of this now & have a deadline to meet so cannot devote anymore time to this subject search right now!

BTW - the quote above was how I got the link in the email from Peter Lech at PCA-OCR, but that link & the 917 engines link on it's sidebar would've made the perfect compliment to the story, but my half-zymers has kicked in & I don't recall where I saw the piece on how the 2L was derived in part from the 917's engine.

Dang!!!! - it was a great connection & I thought I could tie the two stories together. If anyone else has seen that write-up where they talked about engineering the 914-2.0 engine redesign of the prior 914/411 1.7L, in connection with the technology of the 917's 10 cyl. air-cooled racing engine, feel free to add in here! I think it had to do with the cams, timing, etc. on the 917...????

...anyone else with 2L 4-banger recall the story?

Pat, you can either leave it here until I have time again next week to look more (or get the laptop back), or move to whatever other forum you prefer.

...gotta get back to my deadline work now though.....

The Connection is Hans Metzger, The Engine Designer.

I think they started out by making sure the 917's engine had 12 cylinders........can u change the thread title?

yes, a 10 cylinder 917 would be running a bit rough . . .

Hey, us old guys have brain-farts too!

Don't know how to change the thread title?? ....but can't look into it now anyhooo!!

10 or 12 cyl. would both run smooth Mike, so long as it's an even number, or even odd over 2 cyls. Look at the 5 cyl VW & Audi engines of the 90's.

Yes, you have pushed my buttons! Big time!

Let's get ONE thing very straight....there is NO connection between a 914 and a 917. NONE. But, I'm willing to talk 917's all night.

For those of you lucky people who have had the experience of hearing not just one, but multiples of the 917 run simultaneosly, then you know my 917 lust! There is no sweeter sound.

But it isn't even remotely related to 914's.

Still, I would give money to just sit in any 917 & fire it up.
Pat

No relationshio to 914's. And I think we should take this topic to the Sandbox.....though I'll let you tell me.

After I watched the video I was looking at some others in the search and then I saw the 914-6

http://www.youtube.com/watch?v=i4L6_cQp09c...feature=related

Aside from being a brilliant engineer and engine designer, Hans Mezger (no T in the last name) did the 917, 935, 936, 956, 962 and the TAG F1 engines to name some.

His department also did development work on the 2.0 4 cyl that debuted in our cars in 1973. That's the only connection I can come up with unless Tom knows something else. Otherwise the connection to that monster car is tenuous at best IMO.

Oh and Tom, what I meant was (I hate explaining jokes - even bad ones) the 917 was a 12 cylinder car ergo one running on 10 is probably having a bit of an issue.

ba-dum-ba

Pat - in addition to the same engineer for the engines of both the 914-2.0 & the 917, there was something about the way they set up the 2.0 bore/stroke timing & cam which was similar to or borrowed from the 917's engine design, which makes sense when the same person designs both.

Unfortunately my "new" laptop is off being fixed, & that was my evening/weekend 'puter to do 914 stuff, so I cannot even get to the proper bookmarks without extensive time searching that I can't do now. I thought it was in the Porsche history write-up at their PAG/PCNA website, but my cursory search there this evening turned up nothing. Sorry, but the laptop crapped out in the middle of doing this originally & I can't complete it now.

I can redo this later, but SoCal Andy did find the 914-6 link in the extra ones I mentioned to also look at, so maybe at least put that in a separate thread for the Sixers & fans of same here.

Mike - apparently my brain was firing on 3 cyls. with your joke! ...got it now!!

Here is the Qoute from Hans Mezger that I was searching for

Click to view attachment

Yeah, that's the one! Thanx T.C.!!!!

I think there may have been more details on other things that he "borrowed" from stuff learned on the 917 et al engines in the one I recalled reading, along the line of stuff they did with pistons/rings, cams & timing (which I'll still try to find whenever I get my laptop back).

So you see Pat, Paul, etc. - while I used the 917 as a "hook" - there really was a connection between the Porsche Racing Dept. & the lowly 914 Type IV 2.0 engine - as well as with the notorious line of racing 914-6's & M-471 race conversion kits available to the dealers, of which many/most here are aware. So this is a little equal time for us 2L fans out here!

This is an apparently far more obscure bit of 914 HISTORY than even I gave all y'all 914 Guru's credit for, but is certainly a "wery interesting" (use the Arte Johnson "Laugh In" voice) & integral part of the "H" part of this O&H Forum!

Pat, Paul, et al - NO BUTTONS WERE BEING PUSHED - maybe a little ear & eye candy to get attention for the link between 917s & 914-2.0s, but a well meaning historical tidbit on my part.

...if this type of history is not appropriate here, then I ask where?? Is the H of O&H only related to CW aspects of street 914s period??

So how do I correct the title after-the-fact, so the connection is clearer in the title/sub-title??

...and so Mike isn't worried about it running rough?
Although Mike, I seem to recall one race back in the day where a 917 took 2nd or 3rd running on only 10!
...dang strong engine, that 10 er 12 er !!??

The 'Moderation Options' menu in the bottom left. Choose Edit Topic Title.

Sorry McMark, but I'm not seeing that Moderation Options menu anywhere, let alone the bottom left of whatever!?

...where am I supposed to be looking??

Thanx for the great 917 engine cutaway!

I don't have that on-screen!

Do I need to select/toggle it on (if so - how/where?), or is it just for the mods & admins??

Go to your 1st Post, hit the edit button on the bottom, select Full Edit, then you can change the Title, add/subtract pictures, etc.

T.C.

One thing entirely different about the 917 engine (& presumably the flat-16 they also developed) is that it's not a boxer engine at all - it's a 180° vee.

Just like the Ferrari Berlinetta Boxer, despite the name. Daft, that.

So what is the difference between a boxer and a 180 V ? Firing order ?

Undoubtedly different, but not the reason. A boxer has a seperate crankshaft throw for each cylinder, so each pair of opposed opposed pistons are at TDC and then BDC etc simultaneously, like clapping hands. An inherently well-balanced design. A vee has a common crankshaft throw per pair of cylinders, which at 180° are directly opposed, so when one is at TDC its counterpart is at BDC. Not well balanced at all, but it does gain a shorter crankshaft, useful if dimensions have to be kept tight.

You do realize there is no such thing as a 180 degree Vee

A V motor is just that, the cylinders are configured in a V pattern. You can have varying degrees of the V, but not 180. 180 degrees is a horizontally opposed that is referred to as a Flat motor

T.C.

Click to view attachment

Yes I know it's a contradiction in terms, but it's a convention to distinguish it from the boxer as they are both "flat" or "horizontally opposed".

For instance, Tipo 207, 015 and 001, here.

Thanx TC, got it changed & updated!

An important feature to be inherently balanced in a 4-6 cyl engine when opposed, less so a problem with more cyls. to balance things out overall in 8, 10, 12, 14 & 16 cly racing engines - not to mention that racers are more forgiving of vibration than in a passenger/street car for general consumption.

The "180 vee" would allow for more cyls. to be crammed in a particular crankshaft & case length as you noted.

So Mezger's thinking on approaching the engine design on both this 917 racer, & on boring & stroking the H-4 914-2.0 were similar, in that he had to squeeze crankshaft modifications in to accomplish the increased displacement in both cases - if applied in the 90 degree opposite axis in each case (per the quote which TC posted above).

From an engine engineering perspective, is this approach of Mezger's similar to what folks like Raby, FAT Performance, etc. are doing to gain stroke & displacement in the up-built Type IV's, or are they doing it purely based on increasing the bore?

In either case, it's important to note that Mezger opened up a whole new era of expanding upon the H-4 engine's displacement & performance by applying Porsche's racing technology to the lowly VW 4-banger!

IMHO the better materials in bearings, etc. & smaller crank created a smoother & more reliable engine as well, since the 2.0's tend to last longer between overhauls than do/did the 1.7/1.8 "standard" type IVs.

I got about 150k out of my 73 2L & could've eked another 20-50k out of it (according to my mechanic Hans), whereas all my buddies with 1.7's back in the day would be rebuilding at 100-120k, as my mechanic Hans always reminded me over the years.

I think it was also due to the fact that the little HP & Torque increase of the 2.0 over the 1.7 made it so that you didn't have to work the engine quite so hard to drive it like a Porsche.

Mike - I liked the 914 pic in the "Avatar dealie" better!

Cheers & Happy !

I think Mezger meant rod bearings not main bearings as that was the mod that allowed the stroke increase to 71mm.

Those journalists ... You can't trust them.

The quote below which TC found & posted above on pg 1 for me was correct - as far as it went:

Click to view attachment

However, you're also correct that the Push Rod Bearings were also changed to make them smaller with better materials to allow the 71mm stroke, but the above noted smaller crank bearings made room for that to happen within the center case castings that were also changed a bit for all of that to happen IIRC. So all of the bearings, crank, pushrods & case are different from the 1.7/1.8 is some respect or another to accomplish the 300cc boost, which is why Jake Raby, FAT Performance, et al can only go up to "1.9L & change" with a 1.7/1.8 case, whereas they can go up to +/- 2.5L with a 2.0 case!

Also IIRC, when I read some other articles on how the 1.7 was enlarged to 2.0 - the Porsche Racing Dept. also tweaked the pistons, rings, sleeves, valves, etc. in both desing & materials to improve the performance, reliability & longevity of the now somewhat over-bored & over-stroked motor - in VW's opinion anyway - but not in Metzger's because he'd used the "better materials" in his racing engine for the 917 & earlier racers.

Ergo, these are all "connections" between the 914 & the Rodney Dangerfield "I don't get no respect" 914-2.0 !!

Also, someone was opining somewhere else here on 914world that Porsche went to water cooled technology on their motors at least in part to be able to use 4 valves per cyl. &/or DOHC. However, a quick look at McMark's post of the 917 12 cyl. engine on pg 1 clearly shows 4 valves & DOHC each side of that AIR cooled engine. IIRC, the 1950's souped-up 356 Carrera motor was likewise a $-valve DOHC air-cooled motor, albeit a limited production one.

And in all cases, when we call our motors "air cooled" - they are in truth "air + oil cooled"!!

So I hope I now stand redeemed for starting this post topic in O&H - in Pat's eyes at least - that there was in fact a fairly critical link between the 914-2.0 - and Porsche's Racing Dept. & their 917s of that same period.

IIRC Jake likes to use the "W and EA" cases as they are stronger for the larger motors. The 2.0L cases have less metal in certain areas and show fatigue quicker.

[quote name='Bleyseng' date='Feb 18 2010, 07:25 AM' post='1275359']
[quote name='Tom_T' post='1274986' date='Feb 17 2010, 12:48 PM']
[quote name='John Jentz' post='1258099' date='Jan 4 2010, 06:38 PM']
[quote name='carr914' post='1250852' date='Dec 15 2009, 11:37 AM']
[quote name='carr914' post='1247288' date='Dec 7 2009, 01:12 PM']
[quote name='Tom_T' post='1247138' date='Dec 6 2009, 11:16 PM']
[/quote][/quote][/quote][/quote]

IIRC Jake likes to use the "W and EA" cases as they are stronger for the larger motors. The 2.0L cases have less metal in certain areas and show fatigue quicker.
[/quote]

I just looked at his website again, & everything from 2270 up say either 2L required or preferred. Not having spoken to Jake personally, I can't say for sure whether he prefers the 1.7 EA/W cases for larger than 2.3-2.4L & up builds (i.e.: his custom race engines), but if that is the case - it may be more related to him wanting to machine the thinner spots in a case for his own engines' needs - rather than those appropriate for the mid-displacement Type IV motors.

However, I have spoken with Ron at FAT Performance here in Orange & he prefers the 2L core for most "street-worthy" upbuilds (we never discussed a race engine for my 73 2L).

Likewise, the guys at GoWesty will only use the 2.1L water-boxer for their bigger upbuilds, as I've discussed them for our 88 Westy - primarily at my wife's prodding to soup-up "her car" after she saw me looking at Raby's engines for "my car" (914)!

BTW - those "less metal" areas are part of what I was referring to as having come from Porsche Racing/Mezger's input.

Jake has mentioned on numerous occasions that he prefers the 1.7L case over the 2.0L case for his large displacement builds ...

Andy

Yes, but the 1.7 & 2.0 we built side by side in 1973; so did they use different case castings? I would not think so, but I never got an answer from Jake on that point.

If the castings did change, at what serial #'s range?

You hear about 2.0 heads cracking all the time, but Canadian heads do not seem to suffer as much as southern heads. So is it strictly temperature related?

Dave, the 2.0 cases were all either GA####### for USA in 73 & 74, then GC####### in 75-76, whereas Euro/World used the GC######. Whereas, the 1.7 was EA####### for USA & EB###### for Euro/World.

They may have come from the same initial casting, but were definitely were NOT machined the same internally, because they're not interchangeable to rebuild a motor for instance. As opposed to the tail & side-shifter (/11 vs. /12) transaxle cases are interchangable, & back in 1980 my mechanic had to replace a worn beyond spec. case for my tranny rebuild then - so I have a 72 /11 case with my original /12 73 case innards & side-shifter hardware on there since.

However, IIRC the casting were different due to the Mezger inspired re-engineering, & that would've been a huge waste of expensive magnesium alloy to cast then machine it all out. Besides, the tooling/molds would wear out over time, so they could just order the new 2.0 rather than a few "extra" general casting molds.

As to the pistions & heads cracking in CAN vs "down south" - as I understand it, most of the problem was with improper installation &/or torquing which caused the cracking after the cars heated up. IIRC there is a specific pattern & process to installing the heads. Apparently those aluminum heads were also sensitive to torqueing on an uneven case surface if not properly cleaned when the heads are R&R'ed. Another issue was folks removing or loosing the cooling flaps under the car body just forward of the engine bay, or letting the oil get too low - so the engine cooling was compromised in both cases.

I had mine as my DD 12/75 - 5/85 for 120,000+/- miles (plus the 45k +/- on it when I bought it in 12/75) - including runs through the desert in summer at 100+ degrees with nary a crack!

I'm curious if the 2.0 head cracking is more prevalent in the later years - than say during the 1st 10 years after production, when there were more experienced mechanics at Porsche & Indies working on them, as well as fewer guys doing the work themselves??

I suppose too at this late stage, many heads could also be machined too far on rebuilds!?

Andy - did he happen to say why?

... anything along the lines I was postulating above - i.e. that he can mill it to his specs for fit - rather than living with those of the factory 2.0 which was thinned down to accommodate the stroke?

Stay dry!
Tom
///////

IIRC correctly the spigot castings is weaker in the 2.0L vs the early cases, the main bearing saddles are stronger in the early cases...
So the early cases tend to not be pounded out as much..
There were pics of the differences on Shoptalk years ago on this....even the 2.0l bus cases have these differences. 2.0l bus cases with high mileage tend to be trash from the beating vs the 1.7 ones.

I think the thinking is that VW had to make a new case design for the 2.0l so why not make it cheaper and easier to cast vs the old 1.7 design..."cost benefits". VW is always looking to make stuff cheaper esp in the 70's as the Mark vs Dollar was killing VW sales.

with the VW cost cutting, but Porsche did some of that too on the 911/912E & esp. the 928s!

Thanx for the info. I sure hope my matching no. GA case is still in good shape inside there!