My 1883cc Porsche 356 912 Blog

Cam choice affects driveability

2007-06-09T09:49:00.000-05:00

I've been putting cams into engine analyzer pro to see what cams are preferable with our 1883cc big bore kit, with a focus on driveability. The first column is idle vacuum in Hg, second is the average base specific fuel consumption from idle to peak torque, and the last column is rpms at which 80% of total torque is available. All shown cams develop full HP by 6500rpm. I have ommitted the Norris 337 and 356 cams, as they aren't optimal for a street engine from the numbers I have crunched.

Stock SC/912 10.2 0.433 1500-2000
Elgin 66509 18.7 0.436 2000
Web 86 18.2 0.438 2000-2500
Elgin 7010-17 16.9 0.439 2500
Neutek SX-1 15.6 0.44 2500
Elgin 7208-19 14.3 0.444 2500-3000
Neutek SX-3 10.6 0.447 3000-3500
Web 86.5 7.7 0.463 3500
Web 86A 6.4 0.479 3500-4000

Don't get me wrong, I loved the SX-3 in my 1883, just in traffic, it wasn't the smoothest, and got poor fuel economy. In a lighter car that won't see daily driving and traffic, I wouldn't hesitate to use it again. That said, if I were to do everything again, I'd choose another cam. I am personally leaning towards the Elgin 7010-17. Obviously you trade off a few hp and rpms for a smoother engine and better bottom end, but I think something around the Elgin 7010-17 is ideal for a daily driven 1883cc.

My new ride

2006-11-10T12:04:00.000-06:00

Check out my newest ride, a 91 Porsche 911 C4 Cab.

http://c4cab.blogspot.com/

Lots of room to grow :-)

Off to new home

2006-11-10T11:50:00.000-06:00

The 912 was picked up yesterday, headed back to GA to DTM Engineering to get the royal treatment. A fellow 356 Registry member purchased the car on ebay and it's going to have a new custom exhaust system built from the ground up for proper tuning and optimal appearance as well as fuel injection. Hopefully with these few upgrades, the engine will be that much closer to the 200HP mark. I will keep my eyes on this one, and even though I have passed the torch, we'll get to see this car hit the track in short order. Congrats Steven!

912 on eBay

2006-10-18T12:54:00.000-05:00

eBay now with BIN of $15,000 with lower reserve.

914 Club Fall Foliage Classic, Columbus IN

2006-10-17T08:51:00.000-05:00

For those who missed it, the fourth annual Fall Foliage Classic put on by the guys over at 914club.com in Columbus, IN, was a success. The weather held out for us and we had our 60+ mile "fun run" around Brown County, ending up at their county park, which is gorgeous this time of the year. We finished with a Poker run inside the park and prize raffle, put on by the event sponsors, myself included. The 914club is one of the largest Porsche communities, devoted to the 914, and we're proud to be a sponsor of the FFC and club alike. Keep up the good work!

We're bogged!

2006-10-05T12:51:00.000-05:00

My 912 made it to Autoblog's RR of the Day.

http://www.autoblog.com/2006/10/04/rr-of-the-day-punched-out-1966-porsche-912/

Thanks guys!

Oil testing

2006-10-04T20:50:00.000-05:00

I've finally gotten around to entering in the results of all the oil samples I had Staveley Services look at for me. The results are quite revealing... If you haven't been following along, most recently oil manufacturers have been reducing the anti-wear additive ZDDP because of longer factory emissions warranties - ZDDP causes damage to catalytic converters. For our purpose, we wanted to see which oils had the target .12-.14% (1200-1400 ppm) of Zn and P. Results are about half way down the page.

http://www.lnengineering.com/oil.html

Hyfire

2006-10-03T13:26:00.000-05:00

Well, the car has had a Hyfire ignition box installed on it for about two weeks. Idle is very smooth and steady and the car also starts easier. I also decided to add in a relay and modern fuse panel in back for all the added electronics along with heavier gauge wire up to the battery.

The only problem I have now is that the tach signal generated by the Hyfire is incompatible with the orignal tach, so i'm researching solutions to that problem.

Routine Maintainence

2006-09-06T15:10:00.000-05:00

Replaced spark plugs. They didn't look too bad for 5,000 miles on regular copper core with only a bosch blue coil. I'm thinking of putting a Mallory Hyfire on the car to further reduce maintainence - I hate changing spark plugs, especially with how bulky the Weber manifolds are. For comparison, I did all four plugs on the 356 in less time than it took to do probably just one. I even had to remove the carbs to get the rear plugs out.

Also checked the valves while I was at it, all looks good. About .004" on the intake and exhaust is the same all the way around.

1966 Porsche 912

2006-09-06T08:59:00.000-05:00

1966 Porsche 912
Originally uploaded by wombatus.

I'm considering a starting a new project and I'm willing to let this one go for $20k. If you're interested, please give me a call in the office. Number is listed here http://www.LNengineering.com.

More testing with the euro tin

2006-08-16T07:07:00.000-05:00

Now that I have the lower euro-inspired cooling tin in place, I decided to take the car to Chicago yesterday. A little bit of highway driving mixed with equal parts of traffic would be a great chance for me to see how the tin would affect the oil and head temperatures.

First off, it took a good 10-20 minutes longer for the oil to get up to 180F. Secondly, once I got going and was cruising with some fairly decent rpms, the oil did manage to warm up to 190F, but as soon as I reduced speed, it quickly decreased to 180F and for the first time I've seen, it actually fell to 175F during operation.

Lastly, head temperature. I would have not believed it with my own eyes but I have a head temperature gauge as my proof. With an outside temperature of about 82F, I was running on my way to Chicago 315F head temperatures while holding in excess of 65mph and 4200-4400 rpm in 5th. Under WOT, head temperatures stayed between 335F and 345F. Lower by at least 10F, that's not the biggest change I observed. Also, in traffic, the head temperatures would drop down to 300F and sometimes into the 290s. Before, once the engine got to a particular temperature, it rarely would drop in temperature below 324F in traffic. Apparently, the lower tin most definately helps keep things cool both at lower and higher speeds.

New Dynomax Muffler

2006-08-16T06:55:00.000-05:00

I chose to retire my existing $17 turbo muffler from Autozone for something a little nicer. I bought a Super Turbo (no relation to the above turbo, which was a cherry bomb branded) made by Dynomax. I picked this new muffler up at the local Farm and Fleet for abour $70. The muffler itself weighs probably three times that of the original. Now, rather than the raspy note the exhaust has a more developed and mellow tone to it that comes to life when the pedal is mashed. I coated it with the 2000F thermo-tec paint (some I had left over), so it matches the jet black appearance of the wrapped header.

Reducing engine bay temperatures and improving air distribution, part 2

2006-08-16T06:48:00.000-05:00

To further reduce the intake air temperature at the cooling fan and overall in the rear of the vehicle, I also decided to wrap the header with a thermal wrap. Manufactured by Thermo-tec, they claim more HP and up-to 70% reduction in temperature of the exterior of the header, compared to an unwraped/uncoated header. Installation is straightforward except for the fact that you are working with fiberglass and it gives me the hives. They have you wet the wrap, then install it. Afterwards, a 2000F paint goes over the wrap to seal it. Just fire up the engine and watch the smoke billow from the exhaust. The cure process generates tons of smoke - I forgot about that and started the car in the garage. Once it stops smoking, the somewhat flexible wrap turns hard.

Reducing engine bay temperatures and improving air distribution, part 1

2006-08-15T09:25:00.000-05:00

Thanks to a very observant Timothy Beradelli (fellow 356 list member and seasoned builder), it was pointed out to me that on cars with european heaters (356's that is), in place of the stale air flapper boxes, there is sheet metal that routes the air past the exhaust ports and further downward.

In an attempt to simulate these missing pieces of engine tin, I fabricated them myself with aluminum sheet, some aluminum angle stock, and lots of rivets. The engine tin is then held in place with safety wire for easy installation (and removal for further cooling testing).

More on oil temperature

2006-08-03T20:08:00.000-05:00

I took a nice long drive of about 35 mi tonight. The weather had cooled down from the highs in the low 100s (F) to a wonderful 74F. A perfect chance to check my oil temps and actually not cook myself alive in the process. At no point did the oil exceed 180F, so I am very pleased. Head temps floated between 290F and 340F, depending on what I was doing.

Flapper Boxes

2006-08-03T17:44:00.000-05:00

It was pointed out to me by fellow 356 Registry list member Timothy Berardelli that the higher than normal oil temps may be linked to the lack of flapper boxes. He made the comment that they are very important to directing the cooling air and I'm thinking now that they may help in scavenging the exiting hot air out of the general vicinity of the engine. He also mentioned that the factory added the pieces to help balance the cooling betwen cylinders. Makes perfect sense to me. I am going to fabricate some aluminum plates to simulate the flapper boxes, as the stock ones don't fit with Skirmants race header.

Fan Belt

2006-07-31T18:16:00.000-05:00

I had been working on my 356 and noticed that the contitech fan belt was tighter than the fan belt on my 912, which had a Gates belt procured from Napa. It also would appear that the Napa belt was also a bit longer by how it sat on the pulley. The top of the belt was roughly at the o.d. of the pulley, and even with one shim only between pulley halves, the belt had at least an inch of deflection.

I decided to try installing a Contitech belt, 10x825, that I bought from Zims. With very little deflection, probably a hair higher than the factory spec, it took four shims between pulley halves rather than the single shim before wth the Napa belt.

Now to the oil testing results. From my last run with the Napa belt, here were the results:

Stop 1: 204F Stop 2: 214F Humidity: 60% Barometer: 29.86 In Hg Falling Outside Temp: 95F (109F heat index)

Now, with the Contitech:

Stop 1: 202F (200F)
Stop 2: 202F (200F)
Humidity: 64%
Barometer: 29.82 In Hg Rising
Ouside Temp: 97F (115F heat index)

It would appear that the new, correct diameter belt helped reduce the oil temperature. I also noticed that the head temperature dropped significantly, about 25-35F and once the load was reduced, the head temps dropped faster.

Moral of the story, make sure you have the right fan belt :-)

Oil analysis results

2006-07-30T14:31:00.000-05:00

I just got back my testing results from Staveley Services on the Royal Purple Max Cycle 20W50 I was running. With some odd 4000+ miles on the oil with extremely high oil temperatures, the oil still managed to come in spec for the viscosity of a 20W50. As far as the TBN, it was reduced from the initial 8.5 to a little below 7. Likewise, the Zn and P levels were reduced about 15%, still leaving in excess of .12%+ Zn and P. I would expect under normal circumstances, this oil would indeed perform the recommended 15,000 mi drain intervals per Royal Purple's recommendations. I would however say that filter changes every 3,000 mi are a must (they recommend every 5,000) when using a high-filtration Mobil 1 filter, as they filter more and hence, fill up with contaminants faster. Of note, there was an abnormal level of copper in the oil, which may be reminants of the initial break in and dyno testing, as I was still running the same oil that was in the engine when it was run in. Staveley recommended to retest, but since I drained the oil already, I plan on re-testing in roughly the same amount of time and miles.

Cooler Performance

2006-07-30T14:11:00.000-05:00

After:

Stop 1: 204F
Stop 2: 214F
Humidity: 60%
Barometer: 29.86 In Hg Falling
Outside Temp: 95F (109F heat index)

Before: (temps in paranthesis are corrected for outside temp)

Stop 1: 220F (239F)
Stop 2: 226F (245F)
Stop 3: 218F (237F)
Humidity: 63%
Barometer: 29.90 In Steady
Outside Temp: 76F

The second stop on the before was at 3/4 of the course I laid out as a stopping point to let the oil cool off. Since the oil was running so cool, I didn't need to stop at all.

From my earlier testing, for every 1F hotter or cooler outside air temp, I registered a 1F increase or decrease in oil temperature. That said, if we were to translate the before #s to todays hotter outside temperature, the highest 226F would have actually been closer to 245F or hotter. The 240F we had registered on an 85F day would have been 250F. That said, our highest temperature of 214F shows that the oil cooler at worse, was worth about 35F cooler max oil temps. Not too shabby!

External Oil Cooler Installation

2006-07-30T13:32:00.000-05:00

Since my last post, we've come to the conclusion that something is ary with the stock oil cooler. I've decided to plumb in an external oil cooler. Typically, a full flow setup is required to put an external oil cooler (or) the stock oil cooler has to be blocked off and an in/out adapter put in it's place.

Since I am running the Precision Matters full flow filter cover, I came up with a third solution. Mocal manufactures various sandwich adapters that are designed to go on in the place of the oil filter. This particular one has a thermostat built in that bypasses 90% of the oil going to the cooler until the oil is up to 180F. Just so you know, the Precision Matters filter takes a 3/4-16 filter thread, so the sandwich gets installed between the housing and the Mobil 1 M1-208 filter, which is the preferred filter provided as OE by Precision Matters.

I chose to use Aeroquip AN-10 lines and fittings and use their socketless hose, for ease of installation. Their socketless blue hoses are good for 250 psi. I also used some "firesleeve" aroung the lines that were closest to the exhaust collector.

To prime the cooler and lines, I filled everything before attaching the lines (a messy ordeal), but it did take 2 qts extra oil and only took some 30 seconds of turning over (with the plugs still installed) to get the idiot light to go out. I turned it over for an extra few minutes to just make sure all the air was out.

I chose to install the oil cooler and fan assembly in the driver's side rear fender, behind the tire. Airflow is ok, better than nothing. I did a test run with the fan in the off position and the oil was about 10F cooler than on my last test, granted the outside air temperature with this test was much higher, with the heat index above 100F.

This morning I wired in the fan off the ignition coil so that it is on whenever the engine is running and took a second drive.

Stop 1: 204F
Stop 2: 214F
Humidity: 60%
Barometer: 29.86 In Hg Falling
Outside Temp: 95F (109F heat index)

I also noticed that if I floored it, the temperature would go up as I passed the slower cars, but when I returned to cruise, the oil temperature would slowly go back down. Prior to installing the oil cooler, I marked the gauge in the car with a line corresponding to 210F, as read at the sump with the Mainely Custom by Design oil temp dipstick. After I installed the cooler, the guage did at Stop 1 read higher than the 210 F mark, but the dipstick read only 204F. Just a curious observation.

In all, the some odd $500 spent on the cooler, fan, lines, fittings, and hardware was a good investment.

And since someone made the comment about the lines going in on the bottom - I filled the entire cooler and the lines, bled them, then installed everything into the car. I plan on unmounting the cooler when I change the oil / filter to ensure that there is no air trapped at the top of the cooler. It's a matter of three bolts and it swings down very easily (and quickly).

Also, as to the location - I got the idea from the back of a Pano or Excellence magazine of an a/c condensor installed in roughly that same location.

Now, some pictures...

Maintainence

2006-07-12T10:21:00.000-05:00

I finally decided to try closing up the cold valve clearances from the recommended .008" to .005". Most definately, it's quieter. I also readjusted the idle mix and double checked my max advance which is and was set to 30 degrees. I just have to go back in and replace the valve cover gasket on cylinder bank 1/2, since it didn't seal up this last time. I guess there is only a finite number of times the valve cover gasket will reseal!

New pressure reliefs and more oil testing

2006-07-12T10:16:00.000-05:00

I received the oil pressure relief springs and pistons from Stoddards on monday. I prepped them and swapped out the older parts. The new springs were slightly longer and stiffer than the ones in there. I'm not sure what it did for my oil pressure, but here's what I found with the oil temperatures.

I chose a route from Momence to just east of the Indiana border @ Route 41. It's a good 15-20 miles each way and has some great spots for going WOT as well as plenty of chances to pass slower big rigs. This is the same route I have taken every time I make a change, to be as accurate in my data collection.

The first roundtrip was on Delvac 1300 Super, barometer 29.90 in Hg and 63% humidity, 76F. The second roundtrip was on Royal Purple Max Cycle. Same barometer reading and 76% humidity, 69F. I measured oil temps at the sump with a Mainely Custom by Design temp dipstick. I chose three spots to check the temperatures and held 3500 rpm constant in 5th with exception of passing, and I made sure only to pass once and took the car to the same head temps each time, about 380F.

Run 1: Stop 1 220F, Stop 2 226F, Stop 3 228F
Run 2: Stop 1 212F, Stop 2 222F, Stop 3 218F

Even with the lower ambient temperature on the second run, i'm willing to say that I was running a tad cooler with the RP, but most definately, the RP was much better at sheding the heat. I'm going to stick to RP from now on in this engine and continue with 3,000 mi oil change intervals unless my testing results from Staveley suggest otherwise.

Between the mileage I put on the car testing the oil and running errands, I'm now up to 4200mi.

Replacement parts

2006-07-06T08:39:00.000-05:00

To once and for all eliminate the possibility of worn springs and / or pistons in the pressure reliefs, I called up Stoddards (800-342-1414) and ordered replacements for both the vertical and horizontal pressure reliefs, along with new crush gaskets and screw in plugs. All together, the parts ran $51.36. For those wondering, it takes qty 2 of each of the following parts: 616-107-511-00, 999-521-016-00, 900-123-025-70, 999-064-010-02. Not too bad for peace of mind. Should be here by next Monday or Tuesday.

Pressure reliefs

2006-07-05T14:49:00.000-05:00

I pulled both the horizontal and vertical pressure reliefs to see if something might be caught up or improperly installed.

Here are some of my observations. The vertical spring is shorter than the horizontal spring and the vertical spring is a lower tension spring- I would have to say that it's about 65% of the tension of the horizontal one. Both pistons were scuffed, so I polished them up till they were smooth to the touch with some very fine emory paper. They now slide in and out easy- getting them out was a tad more difficult.

Idea: Maybe, just maybe I switched the springs on accident, or maybe they were that way to start? Should the taller spring be in the vertical pressure relief. It would sure make sense to me that I'd want the stiffer one there, since replacing the spring in the vertical pressure relief with a spacer would force all the oil through the cooler.

I'd like to say thanks to Ron LaDow of Precision Matters for helping me troubleshoot the pressure reliefs. Hopefully we can get to the bottom of this. I just want to make sure that indeed it is the oil and not some other external factor throwing my oil temperatures off.

More on oil temp

2006-07-04T17:48:00.000-05:00

I again drained the Delvac 1300 and refilled it, but this time I used a racing oil additive supplied by CMW Racing that had been blended with the Royal Purple, just to make sure it wasn't the reason for the lower temps. I again took the same drive and the weather conditions were the same, with exception of humidity, which fell from 71% to 51%. The oil gauge again registered 240F after some spirited driving, but the dip stick measured lower by at least 5F lower than what the gauge indicated, which I can probably dismiss as climatic changes or gauge error. I now plan on switching back to RP to see if I can duplicate the results I had previously attained. Some may squirm at the thought of 240F oil, but you have to remember that I'm running oils designed to see prolonged high temperatures. Even the delvac 1300 super, which is a dino oil, is rated for continuous temperatures up to 150C.