Polo motor build for junkyard coupe 58367

[roy mawbey]

Justin,

So much thought is needed and the cash as well. Make a mistake and I think this is such an interesting project that has to work when assembled. Really interesting reading it and yes those pics are suberb.

Roy

[356hunter]

Justin, have you given any thought to the aftermarket valve covers used by Dean that have Porsche cast into them. They are rounded and look kind of like Carrera 2 valve covers? I thought they were trick and had 4 cam look to them.

Michael Foster

[JTR70]

Hi Bill,

Thanks for the suggestion. What an exotic process. I checked with a few outfits but they only want to deal with production runs; no one-off type jobs. So, they're going to have to be TIG'd back together locally. The guy who's going to weld them knows his stuff right down to the pre-heating of the assemblies in an oven before laying down any tacks so I'm pretty confident that they'll turn out okay. Famous last words.


My 901 swing-axle conversion is still sitting in the corner of my shop. Once Bill finishes all the machine work on the engine I'll start planning and getting him started on the custom flange, machine work to the case and the side covers for it. This entire drivetrain had such a long way to go.
Thanks again for the welding suggestion.

Absolutely Roy, a ton of time spent in just the planning. Especially on the tin work for the 4-cam shroud. I've lost track of the amount of hours I've got into ensuring enough air gets to that rear cylinder and I'm still not done. As far as the money goes I'm thinking its going to approach 60K by the time its a full "turn-key" engine with all parts and Machine shop time.(not including my time in making and ducting the shroud to work)

I'm very familiar with these covers Michael and I was originally going in that direction until I decided to build this block with all 964 components.

Once I saw this guys engine I wanted to build mine as a 964 in miniature (as Mark said)too. Those custom covers also run 1k a set so I decided it wasn't that important for it to read "Porsche". That money will be better spent on an ARP head stud set.
Thanks for all the suggestions you guys!
Justin

[356hunter]

Nice picture of engine with the 964 valve covers. Does owner have website showing his engine build?

Michael

[JTR70]

He's a member here but has since gone dormant. He had posted a bunch of his progress shots but for whatever reason most of his images have been lost. Something to do with his host server I'm guessing? Its here: http://www.abcgt.com/forum/6-Hot-Rod--Modified-356/1845-The-Polopolus-4-cylinder-911-engine.html?limit=6&start=30
User: ADV-Performance

Here are some shots of the finished engine.

4 cylinder 964 engine....

[JOP]

Wow, Justin it looks like a package of real power to be installed in a 356
Do you take bookings for "testdrives" already? I'd like to get put my name on your VIP list

Henry Schmidt @ supertec makes some really nice head studs for the 911 IF you havent already done your shopping


http://www.supertecperformance.com/new-porsche-products.phtml

To bad that so many pictures are gone from ADC-Performace

[JTR70]

Thanks alot Per, I'll keep them in mind.

4/2/17

This entry is months over due as I've been wrestling with and obsessing over the final shape of the forward lower closing tins. As time has allowed I've gone through several generations of shapes before I finally settled on one that suits my needs with the 964 chain boxes I'm running while giving me the final presentation I'm looking for. I know, who really cares how it looks as its just lower closing tin for god's sake but... I care, and if I don't like looking at it I'm just never going to be happy.






This was where I was at several months ago and little did I realize I was heading in the wrong direction. I was relief cutting the tin to accomidate more of a 911 intake arrangement.


By a timely coincedence I recieved this photo along with several others from Dean P. The Polo motor above is one of two Polo engines being fitted with 4-cam blower housings which are going into a pair spot on 550 replicas that Joe Cavaglieri is building. I had seen this engine several years before through Bill but they had yet to build the lower tins. BTW it was this engine that inspired me. Anyway, these are alloy mock-ups and the final parts will be done in steel but the basic shape just knocked my socks off. This is how they should look! The intakes manifolds are custom casting they did to replicate the carb position on a real 4-cam motor; Yet another critical build detail I was going wrong with.


After studying Dean's shots I was now completely unhappy with my rudimentary triangular extension. This is the difference between a pro and a novice like me.


Another detail I missed was how the lower tins flare and expand off the shape of the blower housing. I was incorrectly continuing the line down to the cam tower.



This began my series of modifications to my first model to achieve a finished look that wasn't so simple looking and yet incorporated ques from both the Cavaglieri photo and the original tin all the while working with my specific application as these other polo motors are running the earlier and wider chain boxes. Not a tall order at all


After many weld , reshape and reweld attempts I had something a little better but I was still having trouble getting a clean relief shape in and around that chain tensioner cap that will eventually occupy that space. Again the earlier boxes don't have this so this is a change I have to make specifically for my motor.



After several weeks and more time spent on it this piece then I ever should have or care to admit I still didn't have the final product I wanted.



Decided to scrap it and began rumaging through my remnant embossed chassis panel sections in search of basic relief shapes then started the expriments from there.



There seems to be a pleat or raised relief where I've marked and I really liked it and wanted to replicate it in some fashion.


However, when you study it from this angle it doesn't exist. The camera and the lighting in that shot was just playing tricks but it gave me a feature that I wanted to somehow incorporate.




As it slowly developed I experimented with an overlap two piece section like the OG four-cam metal showed above.


I was getting closer with sweeping shapes and the pleat effect I wanted but..


It sort of went its own direct by the time I closed up the face.


When I shut the lights off for the night I thought I was done but the next day I realized nah, I hate it. Back to the drawing board.



Final example. It had to be I had spent way too much time on just this one lousy corner and still had three more to go. I changed the lower concave relief to convex with a sweeping relief as it approaches the tensioner cap for clearance and that turned the trick and got me to a smoother and more flowing shape I wanted. I'll post more photos of it next but its at least not that blocky-triangle piece I originally had in there.
I know this was all overboard and crazy but I'm much happier with it now.
Thanks for looking!
Justin

[roy mawbey]

Justin,

It took me quite some time to go through all the photo's to understand the situation. Finally towards the end it became much easier to see exactly what you wanted. The final photo does show what I would want to see myself. When finished off I think it will look ' in keeping ' with the flow of the other casings. Really so difficult to get your head round that. But... worth all the time you have spent getting there.

Half way through my study of the problem I wondered if a form of templates could be made but with all those opposing curves it would be difficult to produce likewise drawing it would be the same. Lucky you had those photos sent to you to keep you on track and finding another way.

Roy

[JTR70]

Thanks Roy, glad to hear you were able to make out "heads or tails" in my ramblings. Yeah, since I can't draw very well I had no choice but to mock it up in steel make tons of mistakes and corrections then go from there.

Certainly more time invested than it was worth to arrive here if I was paying someone but I finally ended up with a shape I can live with.

Remounted one more time before I trimmed away the excess metal. Tack welds dressed so I could do some light planishing and shape adjustment.

Its about right down the middle as far as the form following function and at the very least it's a shape I can now live with. Have to as its way past time to move on. I can't waste any more time on this one section.

After a nice bath in acid to get it clean for TIG welding.
Thanks for looking!
Justin

[JTR70]

4/8/17

Stitching it up. From a few weeks ago.

Remounted before TIGing to preserve shape and mount hole alignment from heat distortion. Made that mistake on the last version.

Much easier to weld with the motor on its side.

Began slowly stitching it together.

Just about welded up.

dipped in acid again then areas in and around the welds planished for desired shape.

I like it alot better than my first attempt.

I'm expecting some slight clearance issues with the eventual cap but it shouldn't require too much adjustment.

Not 100% done but close enough for now.

Moving onto building a mate for the right side.
Thanks for looking!
Justin

[roy mawbey]

Justin,

That result was worth the effort!!It looks in keeping with the shroud and blends in very well. Hope that cap will fits on ok!!

Roy

[JTR70]

Thanks for saying so Roy, I really appreciate the positive feedback on it! I still look at very critically and think I could have done better but it really is a case of form following function first. I'll just have to learn to love it because I just have to move on. If it does its job properly I like it even more. Thanks again!
Justin


4/9/17
Right side closing corner.

Planning out the best position and trimming off the excess next.

BTW: these side pieces are the inner closing wall with the relief shape for turning clearance. As I rumaged through my scap sections this relief shape made for a great starting point and provided the expansion profile I was after.

initial trim and beggining to wrap it around the corner with a little heat along the way.


Began adding in the second shape and relief cutting it for desired profile.

Slowly worked it in, added more reliefs so I could get it to sweep then taper back toward the housing at the top.


Shooting for as much symmetry as possible.



Beginning paper templates to figure out a shape for that last inner section.
More later...

Thanks for looking!
Justin

[JTR70]

4/16/17

Right lower closing corner continued.


Finally settled on an expanded/swoopy profile then began tacking them together.

Mirrored the left as close as I could while allowing it to work with this sides requirements.

Went back to paper to develope a closing shape that would work and that I could live with.

settled on this funnel profile.

Next will be trimming for butted end joint.

Basic closing shape completed.

Vantage point I'll be seeing most of the time once its all said and done.

This side went alot quicker. Sure helps to have a basic settled on shape to copy from.



Trimming and carefully locating and drilling in the mount holes next.
Thanks for looking!
Justin

[JTR70]

4/26/17

Cam tower and valve cover sectioning complete.

Bill was finally able to finish sectioning these parts so I can move onto the tricky part of getting them TIG welded back together with as little deformation as possible.

Lower covers sectioned just like the towers and upper covers before.

Won't be a seamless transition around this lower portion but will detail shape it as best as I can after welding.

Other pair bolted to the Jig plates Bill made for me.

Definitely the Long-way home but I couldn't be happier with how everything is turning out so far.

Quick mock up on the engine. Well, one more step closer.

TIG welding is next for these.

Thanks for looking!
Justin

[roy mawbey]

Nice work Justin I am sure you will be pleased to look at the work you did every time you lift the lid. It blends in so well.

Roy