Re: Resucitar la carrera - Rebuilding the 1968
Posted: Sun Aug 14, 2016 11:06 pm
Have you ordered the 356 pulley yet?
For Your Air Cooled Pleasure!
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.Piledriver wrote:Have you ordered the 356 pulley yet?
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.FJCamper wrote: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.
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.Piledriver wrote:Its the CHT you need to be concerned with.
All that dry sump plumbing should help keep the oil cool.
Thank you for your shareRHough wrote: ↑Tue Jul 19, 2016 1:05 pmAfter 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.
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/
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?