Another hot rod

Quote:

---

Originally Posted by Flunder

Hi Aaron:

Yes, that is John D's still-born GTU car.

It was a no-sale twice on the 'bay. His daughter did not know alot about the engine but knew it was something special as she had accompanied her dad to PCA events for some years - she drove it too.

Wheels were 10s and 14s, transmission was a G50 with a close ratio gear set and limited slip. Raised shift tower by Fabcar who also provided a hydraulic clutch set up and their hanging pedal cluster with balance bar. Big aftermarket brakes, needle bearing coil over suspension, old school club car.

I think the RSR race pump and support bracket, 2R throttles, amber shroud, Bosch eight pin boxes, 906 fan, etc. are all pretty clear in the pics. That's what tipped us to the engine. I telephoned the seller and she sent me the ANDIAL invoice, dyno sheet and other documentation. I think that was in late 2006 or early 2007. You may recall we exchanged some posts on it in another thread back then.

One of our fellow board members (thanks Jim) had known the owner and the background of the engine. We discussed it at some length and spoke to the guys at the shop where the 2,9 work was done.

It seemed like a compelling opportunity to get an interesting engine for the hot rod.

Also, chasing old race parts is fun, I guess because no one could buy this stuff from the factory back in the day without an FIA license and a track record of good finishes.

I had heard about and read about the 2R 41mm high butterfly but no one that we knew had actually seen one at the time. Many said the set up simply did not exist.

Matt B had NEVER had a set sent to him for a rebuild - although since this set-up came to light he has had another in for service. The one he had in for service had been opened up to 43mm. Of course, E-H Racing Porsche in the UK has had a few of them.

Finding the 2R injection set up really got the hot rod project focused.

---

#200310463614 = 917 twin plug distributor on eBay

Tom....I remember hoping all the great hardware on that car would go to good use....I see it has. Kudos to a car done right!

:)

The engine builder was a little unhappy with the original cams that were in ANDIAL 129.

It is likely that we will use this spare set of RSR factory grind cams for the hot rod.

I hope there are some guys interested in old parts out there; I took pics of the components now before the engine goes back together.

RSR Cams

The image below shows the RSR cams. These are made with four cam journals made for greater rigidity than the three journal cams that preceeded them, and are gun drilled for center oiling (the rear of the hole drilled the length of the cam is plugged to keep the cam pressurized for lubrication through the holes in the cam lobes to feed oil to the rockers).

Here are the specs of the factory grind RSR cams:

RSR Lift I/E: 11.79/11.43; Duration I/E (deg crank) 278/267; Lobe Center (deg camshaft) 101; Intake Valve Overlap 6.1*-6.3*

The main difference between the RSR grind and 906 grind is that the RSR has a slightly larger lobe center. The larger lobe center has the effect of reducing Intake Valve Overlap. The reduction in Intake Valve Overlap contributes to enhanced dynamic compression. Dynamic compression relates to the maintenance of compression when both valves are open.

Four journal cam towers

These cam towers are interesting to the engine archaeologists among us. First off, note the early casting date indicating that these parts were made in 1972. This is a very early date for a four journal cam tower. Keeping in mind a 72 casting date, one should next consider that there is no provision for spray bars on the cam towers. As there is no provision for spray bars, it is certain that the manufacturer intended these cam towers for use with center oiling camshafts.

The only engines using center oiling camshafts in 1972 were the 2,5 ST engines, either Type 911/70 long stroke or Type 911/73 short stroke, or the early 2,8 RSR Type 911/72 engine.

Taking it one step further, as a general proposition, it is accepted that all 2,5 cars used three journal camshafts. So these towers are unlikely to have been on an ST, unless it was pressed into use later after the end of the 1972 race season for development of the 2,8 cars (as Raj, Hugh, Gib et al have been educating us about on the Ultimate ST thread).

So to conclude, as these cam towers are made for four journal cams, have no provision for spray bars and have 1972 casting dates, we can identify them as being made for engine Type 911/72, the early 2,8 RSR.

Chain Box Covers

The dark magnesium chain box covers are sand castings and have a port machined into them to mount the pressurized oil line on the outer surface of the cover. On the inner surface of the cover there is a cam oiling "button" (refer to the third image below) that mates up to the drilled snout of the cam. This set up provides a steady stream of fresh oil into the cam. Each cam lobe has a small hole through which the pressurized oil feeds onto the lifter (back in the days of forged rockers, the oil fed onto a lash cap).

901.105.063.11 Cover for chain housing, left
901.105.064.11 Cover for chain housing, right
901.105.592.01 Axial shaft seal (2)

This cam lubrication system was first used in 1965 for the Solex cams on the first version of the Type 901/01 engines and then on all subsequent race engines up through the Type 962.

This set up came from a PCA member/SCCA racer in Wallingford, CT who stopped using these parts some years ago when his engine was updated to GE80. Donor car unknown.

Helo Raj:

The number on the bearing that we are looking for and which is shown in the image below is:

912.142.02

The overall width of the bearing is 23.90mm.

You can see the bearing is shaped distinctively like a flattened "u" in cross section with a thrust surface on both sides.

I think a 912 prefix indicates a Type 917 part nbr.

I sent you a PM.

I appreciate your efforts and extend a big Thank You for the help!

Most hot rodders pay particular attention to the exhaust system.

The exhaust system for this hot rod will consist of the 3,0 factory headers that came on the ANDIAL engine feeding into short diffusers ("kurz diffusoren" in the parts list) which in turn feed into a 911R style rally box.

The rally box provides some minimal baffling but is a bit noisier than what you would want for your daily driver.

The rally box style exhaust system was widely used on ST and RSR in period, generally for rally use but not unknown for circuit racers.

The rally box is a two-in, two-out system and has two big 42mm outlets. This system is essentially a somewhat civilized megaphone exhaust. They are too noisy to pass the Db test for DE events. Considering the cfm capabilities of the induction system, 41mm I an E ports, long duration high lift cams and 2,9 litres of displacement, this exhaust system should provide decent flow for the job.

Modern exhaust systems flow better and are much quieter, but the theme of this particular project calls for a factory style 71S hot rod.

The first image below shows a set of quick release clamps. The small clamps are used to attach the big end of the short diffusers to the two inlets on the muffler. The two large clamps are used to attach the muffler to the engine mount bar. I have not found factory part numbers for the quick release clamps.

Back from my AutoX days I recall an RS with Maine plates that used the three pipe version of this system and had these clamps. I have also see the clamps on a 914-6 GT.

The second pic is a period image of an ST rally car. Note the steel bumpers and a license panel which has been "relieved" and shrouded for the exhaust outlets of the rally box muffler. The shiny muffler straps may well be quick release clamps.

Special note to Gib: there are holes in the flared steel rear bumper for deco mouldings on this ST - just like the FIA homogation car pics you posted earlier in this thread.

The third image shows the system as made up for the hot rod - the system is not a factory original but looks the part. I suppose the factory systems were made by Leistritz, the oem manufacturer of the 901/1 mufflers on all longhood cars. The headers, diffusers and muffler will be sent out to be HPC coated to maintain looks and longevity.

If you have the old copy of Excellence with the article about Tom Butler's orange RSR project, you can see the full system as described above. Tom has his made up with a third outlet and caps for road use, just as many were done back in the day.

Raj;

Thanks for the pics of the exhaust.

These are the part numbers as listed in the April 70 Spare Parts List Type 911S Competition Type:

901.111.041.00 Exhaust gas line left (they mean the exhaust header)
901.111.042.00 Exhaust gas line right
901.111.043.00 Diffuser (2)
901.111.015.01 Muffler

The 901 prefixes on these parts indicate that they were catalogued back in the days of SWB cars. Of course, there was only one, very particular SWB that used them as original equipment, the 911R.

From memory, it seems to me the part number stamped on an original rally box muffler is 901/20 but I could be wrong. PM me if you have a moment with the correct number.

Thanks again for posting the pics and I look forward to reading your account of the development of the roll bar pattern up through the RSR.

Tom,

Do you have a source for the quick release clamps?

Stu

Hi Flunder-- Nice project. You might try Carl Thompson in Long Beach California for the 912 bearings. He has built the last real 917 from the demo chasis the factory was touring around in the day. I dont have a phone number. Try Andial Parts in So. Cal. or Porsche North America Racing in Santa Ana. California. Regards Chris Early S reg #205

Quote:

---

Originally Posted by varunan123

Stu

Here is one for clamps and muffler


Raj

http://www.magicsix.de

---

Excellent link Raj - but they are gone.... (got really excited tho!)

Stu

Quote:

---

Originally Posted by varunan123

Stu
Don't worry i will get you some will talk to robert.
Raj

---

me too... please Raj!