Welcome to the slippery slope..., Porsche 6-cylinder conversion Options

[mb911]

Been awhile since I've posted any project news for this, it's been cold here in MN and my garage heater isn't set up. On top of that I've had the 3D model project and the baby keeping me busy.

I've been collecting parts and planning though. New valves and springs, heads are ready to go to the machine shop to get rebuilt which will probably be next month at some point.

Also scored a set of MSDS headers. Went with the 1.625" O.D. headers. Wanted to be able to increase the displacement in the future if I want to, and these shouldn't be too big for the 2.2.

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I've got the engine case half 3D models and the carb 3D models pretty much done, so that means it's getting to the point of assembly. Or at lest further checking... my next step is to assemble the crank in the case, torque, and check for binding.

Awesome score but 1.625 is going to really be large for anything less then 2.7 .. You will see that when running carbs the signal at idle will be very weak and hard to tune.. Had extensive conversations with Richard at Pmo as far as that he begged me not to sell any headers or heat exchangers to anyone running carbs on an engine less then 3.0 in displacement in 1.625 thus the reason why I started making 1.5" heat exchangers and headers.

Sorry if I am a downer..

[Optimusglen]

In your experience was it 1.625 I.D. or O.D. ?

When I chose these I was discussing the size with Marty at MSDS and he didn't seem concerned with them on a 2.2.

[mb911]

In your experience was it 1.625 I.D. or O.D. ?

When I chose these I was discussing the size with Marty at MSDS and he didn't seem concerned with them on a 2.2.

Tubing is always measured O.D. so 1.625 O.D.

It will run just fine above 2k but below you will run into issues.. Factory heat exchangers for a 911 are 1.5 O.D. from 65-74 and ssis were the same for a reason. Even the larger 3.0 and 3.2 ssi sets ups were 1.5 o.d. that though was because thats what John from the original ssi had on hand..

Personally have built and sold 1000s of exhaust over the years and semi recently learned of the signal issues after PMO called about issues with one of my customers set ups. He was running a hot 2.4 with PMOs and couldn't get it to idle right after multiple jets, venturies, emulsion tube changes Richard par was stumped amd called me up all kinds of upset. This was with 1.625 OD. We then switched the customers set up yo 1.5" and everything tuned perfect..

Just trying to save you some frustrating moments..

[Optimusglen]

Thanks for the feedback, I have some messages out to a couple people on the issue. Might need to exchange these since they haven't been mounted or coated yet.

edit: heard back from Aaron over at Flat Six, the guru I try to run everything through. He agrees that 1.625 is probably too big. Now to see what Marty thinks and if I can swap these. I'm guessing I'll have to pick up the shipping charge both ways, so that sucks...

[mb911]

Thanks for the feedback, I have some messages out to a couple people on the issue. Might need to exchange these since they haven't been mounted or coated yet.

edit: heard back from Aaron over at Flat Six, the guru I try to run everything through. He agrees that 1.625 is probably too big. Now to see what Marty thinks and if I can swap these. I'm guessing I'll have to pick up the shipping charge both ways, so that sucks...

Sorry about the bad news and ruining your day.. And sorry about the expense of shipping..

[Optimusglen]

Looks like I'll be holding onto these until the engine is in and my tuner gets a crack at it, if it's bad I can send them back and exchange for a set of 1.5's.

[rgalla9146]

I doubt if I will do Carrera tensioners.

Slippery slope........

(IMG:style_emoticons/default/beerchug.gif)

And at 800 for a kit crazy money.

On the Carrera tensioners. When I asked my engine builder why we did not go with the oil fed tensioners he said that even though Porsche used them on the later cars rebuilding the old 930 tensioners was very low in price and that they work for a super long time.
Plus he said they are like shock absorbers and as they may go out at some time it does not just fail without some noise giving an owner a notice that they are not working right,

Now the complete failure of one of the tensioner could mean destroying you engine. I feel that I will be fine. Keep clean oil and who is going to put 150,000 miles on there 914? The last set of oil fed tensioners was $500. I guess the price keeps going up.

Bob B

I agree with your engine builder.
Use the 930 part number tensioners plus safeties and
you'll be safe and secure.
Ask him about the later chain idlers with the wider support.
They provide an additional insurance.

[Optimusglen]

Update: Today I went out and did a test assembly of the case, bearings, and crank. The goal was to see if the crank would turn freely while the case was bolted together and torqued. Unfortunately it looks as if my case falls into the same category of so many other mag cases. The crank turned smoothly at initial torque of 15lbft. But when brought up to 25lbft it would not. For referenced the case and bearings were clean, light smear of regular engine oil on the bearing surfaces.

So it looks like I'll be saving more and then sending it out to Ollies.


On the bright side, the type 4 1911 is still there and should run fine this season. And I have everything to do a side shift trans swap to bring the driving enjoyment up a bit.

[BK911]

2.4 crank and rods.

[mb911]

I am sorry to hear that.. (IMG:style_emoticons/default/sad.gif)

[Optimusglen]

I am sorry to hear that.. (IMG:style_emoticons/default/sad.gif)

It's ok, it's what so many had said would be the case so I can't say it was a big surprise. At least now I'll know that it's all set when I do put it together. Again, I'm glad I didn't start stripping down the 914 and selling off the type-4. It'll be a strong runner for this season.

[gereed75]

My experience is that main bearing bores ovalize and that is what squeezes the crank when torquing. Ollies will mill the case split line and rebore the main bosses. They will then measure the deck heights and will provide spacers to correct the cylinder heights back to factory. Very slick and puts you back at square one for the rest of the build.

[Optimusglen]

Thought I should update the thread.

I got my heads back from the shop, seats were virgin so that was nice. New valves, guides, seals. Springs were low mileage units I had found else ware, all were checked and were within spec. He had one exhaust stud that he had to drill/replace.

I love new parts.

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So now is where I am supposed to start saving for the case work, except I already had a few other things in the pipeline for the 914 so I'm finishing these off.

First things first, the front end needed a bit of an uplift. I liked the LE style front valence, and the non-foglight grills I had were warped badly. I found a page detailing the use of modern driving lights in place of the OE fog lights. It was good on my wallet so I went through with it.

Fit and finish isn't the best, but acceptable for a driver. Light output will be far greater than what I had. They are driving lights, so much brighter than fog lights. I will be aiming them so that they don't blind people.

LE replica valence is of great quality. I had to drill the mounting holes of course but it all lined up pretty well. Quick shot of satin black to tie it all in.

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After that I pulled the meatballs (roundells, number dots) off. they were ok for a season but I wasn't feeling them anymore.

This bumper has seen far better days. New, or even good condition used bumpers are out of my price range with the 6 build going on. So I'll either leave it as-is, or I may try to pound out some of the dents and then paint it gloss black... project for another time I think.


Next on the list is the side-shift trans swap. Rudedude set me up with just about all of the parts I needed. Ordered a couple soft parts since I was going to be in there anyway and I needed the conversion bushing. I got it all stripped down and was ready to start reassembly and that's when I discovered that the new conversion bushing I had ordered was the wrong part. I looked online where I ordered it and sure enough it's listed as a part for an early-late transmission conversion. Turns out it's just a stock replacement for an early car... so a new one is ordered and should be here this week.

The trans and bar are in at least. I'll be rebuilding the axles with new boots and grease, and might try to do something about my muffler.

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All in all, R&R of the transmission with the engine and exhaust still in place was easier than I anticipated. Using just a floor jack. To help line up the drive splines I grabbed both of the axle flanges and turned them back and fourth the same direction while simultaneously pushing the trans to the engine. Snicked right into place on the first try.

This weekend I am going to try and finish the swap and get the car tuned up. Might make it out to a local swap meet for another project of mine... a 2007 VW Passat...


Finally, next on the list is a new set of vinyl for the roll bar. It's been sitting in a box just waiting for it to be warmer. I have some new chrome trim I'll be mixing and matching with what I have to get the best possible set.