Page 20 of 25

Re: '71 Super Beetle Autocross Build

Posted: Sun May 27, 2018 6:45 am
by ChadH
Port matched the manifolds to the heads, and cleaned up casting shmoo. I also pulled the valves, and cleaned up the castings in the ports and chambers. That was a little nerve racking, since I didn't want to nick the valve seats with a sander. It was kind of like playing the game "Operation." I was carefull not to change any port or chamber shapes.
Image

And then I want down the rabbit hole. I fellow racer sent me a video of him polishing his 914 heads. Well - then I had to do it. I'm not sure if it was worth the effort, but they sure look pretty now. I didn't polish the exhaust ports, since frankly, I got lazy and didn't want to spend another whole weekend mucking about with the heads.

Image
Image

Yes, that's the dishwaher. No, I'm not getting a divorce. The heads were clean enough to eat off of before putting them in. I wanted to be sure all the polishing compund was out of all the nooks and crannies before installation. I gave the valves a quick lap with some compund, just for good measure, but I don't think they needed it.

Image

I didn't cc the heads before, but the chambers are advertized at 54ccs. After the polishing, they all came in at 54.3-54.4ccs, so not much material was really removed.

Re: '71 Super Beetle Autocross Build

Posted: Mon May 28, 2018 10:59 pm
by FJCamper
Hi Chad,

The old term "port and polish" faded away to just porting as hot rodders gradually discovered polishing intake ports and combustion chambers did little for performance. Polishing intakes turned out to be counterproductive as turbulence was reduced and mixtures suffered. Polishing combustion chambers at least reduced sharp edges (less chance of detonation) that might stay red hot, and rough surfaces where carbon might adhere.

"De-coking" was a real thing in the 1950's, as carbon buildup was everyday life. That's why we had so many "top oils" and carbon burn-out and cleaning tricks. Today, just like Chevron advertises keeping your valves clean with Techron (gas mixed with 400 ppm of polyetheramine) the chemicals do the decoking for us.

I do admire your ambition and application.

FJC

Re: '71 Super Beetle Autocross Build

Posted: Mon May 28, 2018 11:11 pm
by ChadH
Well, I was going to set up the valve geometry. I turned the crank and "clunk." What the? Yup, I missed clearancing the cam/connecting rods. I swear I turned the engine around several times when I assembled it...Obviously I didn't. :oops: So, I tore it down, and found a couple spots that were no good, clearanced them, and re-assembled the engine. At least I found it now, and not on startup.

Image

Image

Image

Image

Re: '71 Super Beetle Autocross Build

Posted: Mon May 28, 2018 11:19 pm
by ChadH
FJCamper wrote:
Mon May 28, 2018 10:59 pm
Hi Chad,

The old term "port and polish" faded away to just porting as hot rodders gradually discovered polishing intake ports and combustion chambers did little for performance. Polishing intakes turned out to be counterproductive as turbulence was reduced and mixtures suffered. Polishing combustion chambers at least reduced sharp edges (less chance of detonation) that might stay red hot, and rough surfaces where carbon might adhere.

"De-coking" was a real thing in the 1950's, as carbon buildup was everyday life. That's why we had so many "top oils" and carbon burn-out and cleaning tricks. Today, just like Chevron advertises keeping your valves clean with Techron (gas mixed with 400 ppm of polyetheramine) the chemicals do the decoking for us.

I do admire your ambition and application.

FJC
Yah, I don't think I'd take on the polish job again, if I had to do it over. The "theory" as I understand it is that the polished surface will absorb less heat, and more of the combustion energy will be maintained as pressure (power.) How much, I dunno. At least I'm not charging someone by the hour for the work. :wink:

Re: '71 Super Beetle Autocross Build

Posted: Mon Jun 04, 2018 6:53 pm
by ChadH
This weekend:

Set up rocker geometry, cut push rods, and started bolting up the exterior bits - hopefully for the last time. Note the absence of a distributor. I used a little bit of "windfall" to order a CB crank trigger / data logger ignition and a few more goodies.

Image

Image

Image

Image

Re: '71 Super Beetle Autocross Build

Posted: Mon Jun 04, 2018 6:59 pm
by petew
Good call on ditching the dizzy. Can't tell you how much I love my crank trigger and electronic ignition. :D

I'm not, "missing the point". ;)

Re: '71 Super Beetle Autocross Build

Posted: Mon Jun 11, 2018 3:32 pm
by ChadH
Monday musing as I await more free time and parts shipments. There's growing enthusiasm in our SCCA region to organize local rally cross. If this comes to fruition, I think my build could be made into decent rally cross machine, with a change in tires, addition of air cleaners, and maybe ride height. Here in the desert, we'd likely be in a slippery gravel parking lot, not the loamy soils shown below. FYI, that's Doug Liebman's '71 super - Dirtfish 2017 RWD Modified champion. I can dream can't I?

Image

Re: '71 Super Beetle Autocross Build

Posted: Mon Jun 11, 2018 10:52 pm
by H2OSB
I know not many feel the way I do about Super Beetles, but I love how versital are.

H2OSB

Re: '71 Super Beetle Autocross Build

Posted: Tue Jun 12, 2018 11:02 am
by ChadH
H2OSB wrote:
Mon Jun 11, 2018 10:52 pm
I know not many feel the way I do about Super Beetles, but I love how versital are.

H2OSB
Yes - and there's so much internet depth of knowledge and aftermarket, that some additional off-road/Baja-ish tweaks will be easy to implement at this stage. If this becomes a dual purpose autocross/rallylcross car, the hardest part will be finding a setup that works for both environments, without significant back-n-forth rework of the suspension tune. I'm getting set to mock up transmission mounts (with hard mid-mount) this weekend. While I'm at it, I might make sure there's tabs to mount a skid plate. I might not make the plate yet, but will at least have a place to bolt it in the future.

..Or I could buy a $500 Craigslist POS for rallycross, and just beat the hell out of that. :P

Re: '71 Super Beetle Autocross Build

Posted: Tue Jun 12, 2018 5:22 pm
by CaliforniaMilleGhia
My friend has a 71 super project , no motor/trans for $350 in the Los Angeles area if anyone cares !

Re: '71 Super Beetle Autocross Build

Posted: Tue Jun 12, 2018 6:26 pm
by petew
I'd own a super in a heartbeat, better still a curved screen L bug. All the right bits. Proper strut front, IRS rear. With the right motor it will out handle just about anything in a corner. Not a great choice for offroad, but awesome for anything else. :) It's a shame they have rubbish insulation and metal which is why they rust so easily.

Re: '71 Super Beetle Autocross Build

Posted: Wed Jun 13, 2018 2:41 pm
by ChadH
petew wrote:
Tue Jun 12, 2018 6:26 pm
I'd own a super in a heartbeat, better still a curved screen L bug. All the right bits. Proper strut front, IRS rear. With the right motor it will out handle just about anything in a corner. Not a great choice for offroad, but awesome for anything else. :) It's a shame they have rubbish insulation and metal which is why they rust so easily.
I originally wanted a curved window super, since I think they look more modern and "Porche-esque." The flat screen has grown on me though, because it still has some old-school beetle look. I do wish mine had the R&P steering, since a new steering box is pricey, and getting a quicker steering ratio is difficult.

While doing body work, there was a tiny hint of rust-bubble from the death-foam area. I looked the other way and ignored it. If it eventually rusts through, I'll just cut it out and install a non functioning NACA duct. Because NACA ducts are cool!

Re: '71 Super Beetle Autocross Build

Posted: Thu Jun 21, 2018 11:02 am
by ChadH
Another engine pic. Installed crank trigger and got anal with wires and plumbing. Just a few more wires and exhaust, and I'm done with the engine.

Image

Re: '71 Super Beetle Autocross Build

Posted: Thu Jun 28, 2018 10:47 am
by ChadH
It's getting kind of lonely in here....

Cut off 3-bolt flanges on exhaust and stinger, and installed a V-band clamp. I plan on making a hideaway muffler too, but need to get the engine in the car to determine how it needs to fit. Also, I added an O2 bung for a wideband O2 sensor.

Image

Image

Re: '71 Super Beetle Autocross Build

Posted: Thu Jun 28, 2018 2:00 pm
by Ol'fogasaurus
Oooo, Ahhhh. Very nice, very nice! Keep an eye on the braided lines as if there is much jiggling around the braided strands can start to fray/break and "get sticky" causing a blood draw. One of the reasons I don't recommend them.

They were not designed to be that long... among other things. The WWII guys got the idea of using them after working on military aircraft (etc.) and it caught on. I still see them on show machines but less and less on working rigs.

Lee