Resucitar la carrera - Rebuilding the 1968

[Piledriver]

Have you ordered the 356 pulley yet?

[RHough]

Have you ordered the 356 pulley yet?

No. My usual sources don't have them (CIP, Air Cooled, CB) I found one but I forgot to bookmark the site. I don't need it for first fire.

The 356 pulley is 3 parts? Hub, Inner and Outer?

Does it use the same shims? You'd think someone would put together everything you need as a kit ...

[FJCamper]

Hi Randy,

The 356 pulley is, at a glance, visually indistinguishable from the VW. The pulley comes in two familiar disk pieces, a hub, and slips on the generator or alternator no problem, and even uses VW shims but the original Porsche shims did not have the circular hole in the center ... they had a stamped shape that fit the hub.

356 fans were not welded, but they were balanced.

Porsche racers used to remove vanes from their fans to reduce drag, and you'll love this. They discovered if they ran a VW generator pulley it slowed down their fan and saved power! They gained top end.

The grass is always greener on the other side.

FJC

[RHough]

Hi Randy,

The 356 pulley is, at a glance, visually indistinguishable from the VW. The pulley comes in two familiar disk pieces, a hub, and slips on the generator or alternator no problem, and even uses VW shims but the original Porsche shims did not have the circular hole in the center ... they had a stamped shape that fit the hub.

356 fans were not welded, but they were balanced.

Porsche racers used to remove vanes from their fans to reduce drag, and you'll love this. They discovered if they ran a VW generator pulley it slowed down their fan and saved power! They gained top end.

The grass is always greener on the other side.

FJC

I figure I'll run it the way it is and see if/when it runs too hot ... if Oil Temp is in the 180 - 200 range I'll call it good.

[Piledriver]

Its the CHT you need to be concerned with.
All that dry sump plumbing should help keep the oil cool.

[RHough]

Its the CHT you need to be concerned with.
All that dry sump plumbing should help keep the oil cool.

Figuring that 90% of the heat in the oil comes from the heads an increase of oil temp under normal conditions would be an indicator that the reduced fan speed is an issue. Of course I'll be looking at CHT as I tune. I think 275°F is what the IR heat gun was reading on the heads. If I see more than that consistently a 356 pulley will become a higher priority. I'll want the extra flow for heat this winter anyway.

I'm doing the harness today, ready ti fire this afternoon or Weds AM.

Did you say plumbing? LOL ... it all fit!

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[Piledriver]

Jake Raby reported high oil temps on his cam break in jigs, requiring an oil cooler and fan.
They had no compression or combustion, just the friction of the rotating crank and cam/lifters/springs, driven externally.

[RHough]

After many more hours thrashing than I thought and correcting a couple of harness issues the engine runs!
It is quiet and smooth. Now I can start tuning a bit. Have to get the gauges to talk to the ECU so I have Lamda and Tach back. Waiting for the Bluetooth adapter so I can use my tablet instead of the laptop.

Pretty cool stuff. Have to study about injector timing etc. Lots to learn!

[Piledriver]

How did the CB750 oil tank setup work?
News? Updates?

[RHough]

Updates!

The dry sump system was a mixed bag. Some good, some not. The system works as far as oil supply goes. The issue I had with it is the size of the output pump. When the engine is at operating temp the pressure is very low. I want to see 10 PSI per 1000 RPM and 30 PSI over 3000. The little 21mm pressure pump is marginal on my engine. 20-25 PSI is all she wrote.

I got a bug up my ass about noise and heat for the winter in Canada and decided that racing the car was not really what I want to do ... so ...

CSP Python heater boxes are not going to cut it.
VW heat exchangers will choke the engine so why have a W120 cam.
The Python is too loud.
The fan speed with the dry sump pulley is too low.

The solution I came up with was to swap the cam for a W100, put real heat exchangers on it and a Vintage Speed sport muffler ... should keep the 125 ft/lbs of torque, drop the HP to about 105 and give me a nice fat torque curve plus heat and quiet ...

So I did a quicky cam swap, decided that the dry sump system was coming off so I could use a full size pulley.

Looked at my old heat exchangers and they were pretty beat up so I got some of the "OEM Replacement" heater boxes that are advertised ...

Put the engine together with a stock oil pump, the W100, and the new exhaust ...

Oil pressure is 80+ cold and 30 hot ... score
Exhaust drone is still obnoxious
OEM Heat? Kiss my ass ... not even close. VW heaters will melt your sneakers, the OEM replacements barely put out 110°F
It was a torque monster ...

Did I say was?

Yep, plans change and I missed the top end the W120/CSP combo gave me.

So out it came to get the W120 cam back in and the Python installed.

Damn ... it is nice to have the snarl back, I added more sound deadener to the engine room and right rear fender to try to kill the drone with some success, a tailpipe extension past the body is the next step.

The engine spins past 6000 with no issues. The power and torque are dropping off at 6500 so it has a seat of the pants rev limit rather than a mechanical one.

I ran down to visit Mario yesterday with a best guess tune and only a little time in self tune. Ran 3500RPM/70MPH cruise no problem with head temp only 235°F and oil temp about 210°F. I topped up on the drive home and got 30.87MPG over 100 miles including a stop and go section of I-5 in Everett.

135HP and 31mpg? Hell yes.

[Piledriver]

Cool.

Thought:Gas heaters rock...
...you want a late model unit or convert a BN2 to a metering pump setup.
I have a BN4 in my squareback as sole heat, and I would not even hesitate to drive it to Canada in February.
(I used the same BN4 from my 73 Bus in upstate NY for many years, kept it when I had to put the bus down.)

The BN4 fit essentially in the same spot I had a "NOS" BN2, which was something of a PITA from day one.
The BN4 worked better in every way from the second I installed it.

I pulled it out of a box I had in the shed for 25 years, wired it, hooked up the fuel line and it immediately rocked.
There were many sad spiders that day.

If they salt the roads there, I'd drive a Kia in winter, but if you live somewhere it REALLY snows like where I was salting is ~useless so they don't bother.

[RHough]

The 'plans change' mention is that I'm not staying in Canada ... moving to Mexico ... the CSP heat is more than plenty.

Got yer PM

[Piledriver]

The 'plans change' mention is that I'm not staying in Canada ... moving to Mexico ... the CSP heat is more than plenty.

Talk about "climate change"

Now you'll need AC.

[Precieux04]

After the untimely demise of the 92 x 74 "Carrera Replica" engine a new thread about the resurrection/rebuild is in order.

The 92 x 74 dimension Type 1was selected to duplicate the Porsche Carrera2 engine in the 356's The goals were 130 HP and 120 ft/lbs. The engine pushed the Ghia to a 7.1sec 0-60 time so the performance goal was met or exceeded. A 356 Carrara2 was slower 0-60 (9.2 sec) according to the road test information I can find. The engine died before I got to the street drags for a 1/4 mile time. Based on the 0-60 of 7.1 the engine was putting out 140+ HP so the car should be under 16sec at about 90 mph at the strip.

Planning and Demise Thread here: http://www.shoptalkforums.com/viewtopic ... 3&t=145538

One of the features of the 356 Carrera that was not duplicated was a dry sump oil system. Thoughts on the Cheap Thrills Racing version are here: http://www.shoptalkforums.com/viewtopic ... 7&start=16

We don't know that the deep sump system contributed to the engine failure but we are taking no chances with the new build.

Cleaning the case after the failure is job one. Bob Hoover has some opinions on this in his blog: http://bobhooversblog.blogspot.ca/2006/ ... -plug.html

His thoughts on oil temp sender placement are interesting.
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I may relocate the oil temp sender there to allow use of the stock OP switch and gauge sender at the standard location. I think the oil return location should see the same temp on a dry sump system as the wet sump. It might be interesting to just add a sender there for the ability to see the temp of the oil coming out vs the temp of the oil going in from the tank. Thoughts?

I also ordered a Krankvent system based on the information in this thread: http://www.shoptalkforums.com/viewtopic ... ase+vacuum crédit

While I'm waiting for the internals I'll toss the engine back together with and empty case to get the oil system plumbing and components laid out to save assembly time later.

After the Weber tuning saga and suffering with 13mpg I'll be going EFI on this engine. Mario from the Dub Shop has a new ECU: http://thedubshop.blogspot.ca/

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Not looking for any more HP, just improved drivability, cold start performance and fuel economy. Sequential injection and Idle Air Control should correct the carburetor faults that I could not tune out.

Can I get it done by August 19 for the drags?

Thank you for your share