Ah, external water mist to cool. Hadn't planned on it as goal initially is to achieve stability without an additional consumable.

Hope you guys don't mind me sharing a few other steps on this that aren't necessarily iron cylinder related.

Noted the bell housing inside the transmission was fully caked in oil/grime indicating rear main or trans output shaft seal. Decided to replace both.

http://i458.photobucket.com/albums/q...ps7c0d0890.jpg

http://i458.photobucket.com/albums/q...ps74bed4d1.jpg

As you might gather from this photo we are no longer considering any book at this point in the repair; brand new trans seal and some foreshadowing:

http://i458.photobucket.com/albums/q...ps0a64c6fd.jpg

As you can see, this is the trans with the trapped seal and a guide tube without mounting screws. After confirming it was possible to see between the original seal and output shaft we determined it was necessary to replace or deal with the inevitable leak. Trans build isn't in the cards so cleaned everything up and slid the new seal in.

http://i458.photobucket.com/albums/q...psbd0bcf9b.jpg

Seated tight.

http://i458.photobucket.com/albums/q...psc568995b.jpg

Fresh powdercoat perimeter tins

http://i458.photobucket.com/albums/q...ps165addd2.jpg

Going up:

http://i458.photobucket.com/albums/q...ps7efd6bcd.jpg

http://i458.photobucket.com/albums/q...ps946a724c.jpg

Fit is perfect... found one of my dozen jegs hats.

http://i458.photobucket.com/albums/q...ps6be69928.jpg

http://i458.photobucket.com/albums/q...ps1a7363ae.jpg

http://i458.photobucket.com/albums/q...psa747f304.jpg

http://i458.photobucket.com/albums/q...psc1f73bd2.jpg

Finished up last night with it ready to turn key with the exception of taking the battery off the trickle maintainer and reinstalling.

http://i458.photobucket.com/albums/q...ps93b0f74f.jpg

Now that your engine is in, I was wondering about how you dealt with the low Rockwell condition of the cylinders.
Early on you spoke about the desire to build a 911 engine (mag case) that would out last the expectations of previous engine builders.
One of the things we noticed in the early 911 years (64-70 or so) was that the cast iron cylinders had a very short life.
We would rarely see an engine with cast iron cylinders that would be in spec after 60,000 miles.
One of the big reasons stated by Porsche for the advent of Nikasil was cylinder longevity. That has proven true in Nikasil engines with 200,000 miles plus, showing little or no sign of wear.
The reason I ask is because in our testing of Chinese cylinders we discovered the low Rockwell numbers and have been dealing with a solution ever since.
Heat treating cast cylinders helps but not much. It still leaves the Chinese cylinder 15-20% off.
With the Biral barrels (cast liners with aluminum fins) heat treating is impossible so we started using Cryo. Tests show good results but we were still not satisfied. We are now having our Biral cylinders Nikasil plated and the product has proven phenomenal.
So what about it Andrew: how did you deal with this glaring quality issue?

This came with dinner on Sunday night. Big fan of the white rice and sweet n' sour chicken... mmm.

http://i458.photobucket.com/albums/q...ps32ff8859.jpg

The big picture answer here is I would much rather replace a worn cylinder set a decade down the road than have a pulled stud ruining my numbers matching engine case because I stubbornly stuck with a materials mismatch. I know there are folks out there loosey-goosey stamping blank engine cases to get back on the road but I'm not playing that game.

Cylinder wear is definitely an uncoated cast iron concern that can be managed within reason. This isn't exclusive to Porsche; had a Jeep Wrangler in the family years ago with the larger straight 6 that was carbur'd. Bought it running rich and the bores were toast; huge lip at the top where the piston travel ended. Overbore, retune = fine; has since left the family but still in the area and running around. Detroit iron, chinese iron, brazillian iron... all subject to the same wear.

Solutions for you to poke holes in:

1) Run proper air to fuel mixture to prevent washing of the bores which would remove the oil layer and dramatically increase cylinder wear. This will mean dyno tuning and careful carb tuning. This is the most significant concern of mine at this point.

2) Managing the temperature of the piston with proper ring gap is of high importance. In simple terms, the hotter the piston, the tighter the piston to the bore and the increased probability of piston scuffing and ring wear which will slowly(or quickly) remove material from the cylinder wall. Careful consideration has been taken to move heat through the gates of materials in the engine with insulation layers to move the hot gases.

3) Synthetic oil after break-in is complete. Superior ring life improvement over most conventional oils. I understand there is a lot of hoopla around running high zinc in these engines but I'm not completely sold on it not being just a fantastic sales pitch. I've had great experience with various synthetic oils in engines with uncoated cast iron cylinders albeit non-Porsche ... and approaching 160K miles with an add-on turbocharger.

I guess the short answer is that you never checked the Rockwell and don't care that huge wear will occur with extremely soft cylinders.
The rings will live (maybe) but the chance of long life of the cylinders is almost nil.

I thought this was an engineering exercise, charting unexplored territory (comparing yourself to Columbus) designed to extend the life of mag case engines not shorten it.

Do you seriously believe that this a compromise most Porsche owners want to make?

Really? This is a compromise justified by the nonsense about matching numbers?

I don't appreciate your snide comments. Your conduct is unbecoming of such a professional as yourself. I'm embarrassed for you and your blind belligerence.

Yes, I'm aware of the benefits of nikasil. With everything else remaining equal will it reduce cylinder wear? Of course. There's no point in arguing it. Temperature control and synthetic oils also will return an extended life which is not "nil" as you state (that's a load of horse *****) .

I would think EFI would allow for longer cylinder life as there is no fuel injected under throttle off conditions which, I believe, is what happens in all carb designs.

Also, it should be noted that documentation of one having a numbers matching engine from 1974 is almost always inconclusive when trying to determine if the car has an engine installed from the factory.

My friend , you called my customers victims, suggested I had my head in the sand, lied about testing iron cylinders, you said I'd eat crow and insisted you didn't want my help.
That's all fine but many people read these threads and I need them to have the information you find irrelevant. Like I said before, my propose here is to guaranty that the greatest number of people see the best results possible.

BTW: your distortions of my statements don't go unnoticed.
I said "the chance of long life of the cylinders is almost nil."
That is an accurate statement when "life" is defined by Porsche norms and is beyond any contrary information you can offer.

That's exactly correct. A solid efi install with sequential control for each cylinder is the best solution. Nikasil is an alternative that will allow you to run sloppy fueling without paying in engine wear. Synthetic oil achieves much of the same result. EFI control is much more precise... warm up, different climate conditions etc... far more adaptable. I would like to swap my PMO kit out for ITB eventually. Maybe this coming winter when looking for more projects.

You're refusing your crow and it hasn't even been served yet. Any result here is irrelevant to preserve your reputation. Wow. Seems you have a horse in this race.

Your statements about not testing cast iron cylinders are in this very thread typed by your own fingers. If you then say you did test and had data then I don't have to say you lied even. You would be served better to just not pick fights, period.

The results here will be available shortly. You don't need to attack to try to salvage reputation if by chance it goes well. Your current body of work speaks for itself. Let these results speak for themselves too. It very well may scatter to pieces on the first drive.

Just sit back and relax. Your engine building practice isn't in jeopardy because someone 3000 miles East went a different direction based upon their calculations and called you on BS they saw.

what rms did you use?

Well, this is a fun thread....

I really think there is a very good reason Porsche only used cast iron cylinders for the low output T engine and then stopped using them altogether when power rouse above ~130 hp.
Pulling away heat from the heads is crucial.

Just a barrel of monkeys in here. :)

Note Harley Davidson/Buell HP capability per liter with cast iron cylinder... in competitive racing for porsche the weight savings may have been a major consideration given the level of competition. I imagine you would not want to share your reasoning with competitors so you might realize the benefit of discovery longer. That is imaginative speculation.

If this is a question about the Rockwell tester and measuring scale,
we used a Rockwell 3R and measured on the B scale.

Transmission seal
 

Andrew - I think you were not as unlucky with your model of 915 as you could have been. If I have this right, the first 915s had the output shaft seal on the diff side of the guide tube and up against a lip. This meant the only way to replace the seal, at least in the stock location, was to disassemble the transmission to the point of pulling the output shaft out. Mucho trabajo.

Next generation had the seal on the engine side against a lip. The factory had a tool for pulling out the old, and then you could insert the new. This must be what you have? How did you pull the old seal out?

Finally Porsche went back to what the 911/901s had - a removable guide tube, and all was much easier. I've not seen any factory explanation for why they did what they did in 1972. Even saving money by casting the tube in (assuming there were savings) doesn't explain where seal went in relation to lip.

You seem to be basing your attack on this statement: Which clearly states I didn't use 90mm cast iron cylinders. Nowhere does it say I didn't test cast iron cylinders or use smaller cast iron cylinders to evaluate the possibilties.

Harley/buell cylinders are actually more similar to biral type. I believe they are made with a cast iron liner with aluminium fins. Aren't they?

Walt you're right, the 72 915 trans had an absolutely stupid main shaft seal requiring a complete dis-assembly to replace it.
At the dealer during the warranty period it was not uncommon (company not technician policy) to just drain a pint from the gearbox to alleviate the leak with the hopes that the transmission would survive the warranty period.



The factory tool.
http://forums.pelicanparts.com/uploa...1369774097.jpg

Believe it or not... it's cast iron for the real performance over there.

HAMMER PERFORMANCE - High Performance for your Harley Twin Cam, Evo Big Twin, Sportster or Buell! 208-696-1250

But shhh... don't want to let the cat out of the bag.

I've shown the quotes I took issue with around cylinder temps and dates. I'm not here to argue with you and there is no attack. I covered this all before and digging up the hatchet is not wise. Not wise at all.

LOL no I was asking what manufacturer of rear main seal he used.
Only took me a SECOND engine drop to realize that Victor Reinz is junk. . . :)

Elring Klinger in the red and white box purchased separately from the host here. I've purchased a lot of additional seals so I have about 80% of the original Victor Reinz kit boxed up new still even with the job done.

The old seal was bottomed out and appeared perhaps a roller bearing was visible directly beneath. It was so loose around the shaft that was what appeared to be visible anyway and I'm unfamiliar with the bearing layout inside the transmission. Normally would run a couple screws into the old until they bottom out and push the seal out but not with what appears to be a bearing visible for fear of damage. There's enough room to install maybe 4 additional seals on the shaft before you reach the splines. Simply bottomed the new seal against the old blown out seal. Sits square and provides better opportunity for oil splash through the gusher to keep it happy.

Neither bearing - ball, roller, or other - nor bushing of any sort reside where the input shaft comes out of the tranny into the bell housing. Closest bearing is on the other side of the ring gear where it leaves the diff area. Ring gear edge is pretty close.

Sounds like you have the intermediate style, which is what Porsche used the tool Henry pictured for. Compared with the earliest, it must have been heaven. And you could use screws. I hadn't thought of them pushing the seal out, but will bear that in mind. I've had using screws and a slide hammer in my reserve of techniques.

I had wondered if the input shaft had enough machined surface to do what you did and install new on top of old. Now I know. Always something to learn.

A bent input shaft (AKA mainshaft) can, I am told, make short work of that seal. Hope that wasn't the cause of the "see through it" gap around the seal lips.

Hi Walt- thanks for the info. Must have been a reflection of the splines somehow inside the seal to the metal surface.

The records for the car (big thick folder) go back to around 1980 without indication of the output shaft seal being replaced. Mature drivers from what I know, zero track time. First guess would be aged/worn seal. If a leak develops soon after install of the new then output shaft would be inspected. I did rotate by hand and did not notice any twist or bend in the shaft.

Unable to locate the clutch lever circlip as the last piece of the puzzle so ordered from host next day air along with a few other bits thanks to their rewards coupon emails baiting me in. My brother got a look at the car yesterday for the first time. He has a lot of experience with MSD and HEI systems with a race team he crew chiefs for. May be adding in the soft touch limiter for the 6A setup currently in there. More updates this weekend I hope.

Saw this today, thought it was funny for myself...

https://fbcdn-sphotos-g-a.akamaihd.n...34467359_n.png

<iframe width="640" height="360" src="//www.youtube.com/embed/PaSRFwxIN_o" frameborder="0" allowfullscreen></iframe>

1974 911 PMO 2.8L - YouTube

SmileWavy

Edit for video link update.

Well...it runs...LOL
Sounds like it's a little lumpy...but tuning should take care of it.
Good job.
Bob

Sounds like, listening to it crank, a new 1.5hp starter would do wonders for cranking. Along with a fully charged battery.

Just a thought.

Thanks Bob. Didn't think it would start up and was about to quit and glance things over again.

Original starter... cranked the same prior to the top end job. The starter looks rough and is lazy. All connections are clean and tight.

Slow drip from the oil pressure sensor/right cam feed line where it goes into the case. After that's addressed only license plates and break-in drive remain.

Andrew...the starter on your car really does sound slow.
Mine used to crank a lot faster...but it was a 2.0 so maybe that had something to do with it.
An old trick for very hard to start VWs at the time was to put a 6V starter in and feed it with 12V.
You had to change the nose bearing in the case...but other than that it was an easy fix...and wow...did they ever spin over!
I wonder if there is a 6V starter (from 356s?) that would do the same thing?
Bob

I see there are 2hp on EBay... I'm going to resist until this one doesn't get the job done. Starts much easier with the carbs full of fuel now.

Going back a few steps now that a hectic week has passed. Here's how the rockers went in.

Clean up all the holes with WD40 and a clean papertowel.

http://i458.photobucket.com/albums/q...ps640c6a65.jpg

Parts for each rocker... new everything except shaft and adding in the seals that weren't there previously.

http://i458.photobucket.com/albums/q...ps26200ec2.jpg


Clean the crud out of the ends with a scotchbrite pad and some brake parts cleaner:

http://i458.photobucket.com/albums/q...psa414cc7e.jpg

Goal is spotless, clean taper and no debris... you will be surprised at the junk trapped in some of these:

http://i458.photobucket.com/albums/q...psa821ddb1.jpg

Light lube/oil of the hardware to prevent galling during installation:
http://i458.photobucket.com/albums/q...ps02099bc6.jpg

Installing the seals and being careful they don't flip inside out...

http://i458.photobucket.com/albums/q...psc3cd3f2d.jpg

I chose to lube the o-rings very slightly to encourage proper seal. I took special care to not drive a lubed o-ring through the rocker arm as that would likely cause lubrication issues blocking oil. I did this by applying a small dab of o-ring grease (same as used on the case through-bolt seals) to the far side housing and to the trailing seal on the rocker.

http://i458.photobucket.com/albums/q...ps5c4700c4.jpg

http://i458.photobucket.com/albums/q...ps23d08823.jpg

http://i458.photobucket.com/albums/q...ps91e5fe96.jpg



Torqued to 18ft lbs and a couple took a bit more. Final torque method was no resistance on the non-torque end tool to show the shaft secured in the housing. Care was taken to ensure the shaft seal was centered in the thin cast of the housing for each and the bolts were removable from within the housing so they may be serviced with the engine in the vehicle and all tins attached.

http://i458.photobucket.com/albums/q...psb64b7fe6.jpg

Oh, and oiled the rockers a couple of times after all tightened up. Couple drops of oil, wiggle it around and return a few hours later and repeat.

http://i458.photobucket.com/albums/q...ps904e373d.jpg

Seemed to be intended for the job:

http://i458.photobucket.com/albums/q...psd06ea604.jpg

Need to locate the unisyn that came with the car. Infrared shows cyl 1 and 5 cooler than the rest. Spritz of carb clean on those smoothed out the idle and raised rpm. Full carb tuning session coming...

Haven't been able to head to the storage area where the unisyn is located so tried an alternative method.

Set idle to 2k rpm with hand throttle.

Spritz of carb clean into each throttle body, one at a time and note reaction of engine speed.

Cyls that bog when carb clean introduced received no adjustment at this time although the reaction on those was uniform.

Cyls that raced or increased engine speed received adjustments of 1/8 turn out in idle mixture (more fuel) until spritz yielded same bog as other cyls.

Exhaust note now smooth, throttle response crisp. Egt for all 6 cyl is +/-20°F. Would still like to confirm balance is precise with unisyn for all cylinders.

Preliminary Idle test shown head stud 8% warmer than cylinder. More measurements once this starts being driven. I will share spreadsheet of data collected for the various components at the same time.

Unisyn found, one cyl was off a tiny bit. Will probably service carbs with kit from the host to be safe.

1st drive/ring break-in tonight and had my brother along for an extra set of ears just in case. Did the wot/engine brake cycle quite a few times. Engine feels great. Zero detonation. Zilch. Nada. Distributor was returned to exact previous position because it was marked during teardown. Power is up from previous configuration with the RS 2.7 according to my seat of pants. More curve above 5k rpm. Changes were webcam regrind of similar profile, 92mm bore (+2mm), compression to 9.5:1 (+1pt).

Returned to garage after 30mins of ripping and idled down. Sink tip 167°F, vc at base of sink 211°F, engine case 188°F. Not sure how but cyl temp at middle was 190°F, head fin 190°F.

Oil change and will report back with more data collection.

http://i458.photobucket.com/albums/q...psee26dd69.jpg

http://i458.photobucket.com/albums/q...psbdfa9a2a.jpg

Before pic to see where we came from:

http://i458.photobucket.com/albums/q...1/IMG_2990.jpg

Nice build!

My personal take on the iron cylinders. They'll be fine. I have a good friend running a twin plug 2.5 long stroke small bore engine that dyno'd at 265hp @ 6xxx rpm. I've watched it run three maybe four seasons without rebuild and he runs 10-12 weekends a year.

I bought a 74 2.7 and plan to build it in the next year or so... Keep us up to date how the cylinders hold up. I may have missed it mentioned, but what pistons are you running?

Thomas

Thanks for the comment Thomas; the silence in here since making the most recent progress has been deafening.

Your friend's engine sounds like quite the healthy 2.5 with that power output and the type of use; I would like to get to the dyno once the break in is complete and the carbs are sorted with confirmed steady air to fuel ratios. Just looking for average, healthy power output as you would expect from a 2.7 with these mods.

Pistons are the JE 9.5:1 92mm off the shelf pistons. Had to hone the cylinders out to gain proper clearance to fit. Hindsight I would custom order the JE pistons a bit smaller to limit the time on the machine for the cylinder work. These take the engine to a smidge over a 2.8L. Time will now tell how they wear and perform; will be run with synthetic oil and a close eye on fueling. If fueling is out too far even with a carb rebuild and tune then going to go efi. I'd really like for the carbs to work out on this though to preserve some of the raw character that attracted me to the car in the first place.

Bosch starter
 

Listed on Ebay 1.8 hp OEM starter or buy a new one for around 245.00.

The slow spinning starters are .8hp.

Porsche 911 Starter Bosch SR 68 x Original Starter | eBay