Unlocking Peak Performance: Porsche Valve Job Results Part 4

[@GarageTimeAutoResto]

Thanks to S-Tec for doing a great valve job on these heads. Assembly next week!

[@openhighwayproductions]

Kudos to the machine shop for a great job on those heads. I am surprised at the low rev limiter setting. Curiously odd piston dome shapes.

[@GarageTimeAutoResto]

9.5:1 USA pistons. Yeah the rev limiter is kind of a bummer. I think Steve Wong chips can increase the limit. I feel the rev limiter in Mac all the time.

[@dra911]

Looks like the machine shop did a great job, looking forward to the assembly.

[@carlmclelland7624]

From the vantage point of a camera, it appears they did an outstanding job on the valves and heads. Kudo's to you as well, for taking the time to measure everything to insure it goes back together, not only according to factory specs, but as accurately as you can do it!

[@GarageTimeAutoResto]

Thanks, I'm happy with the work that S-tec did. I know it's not easy, because I've done some valve seat grinding and seat installation before on my 912 heads and it's tricky. I like to think my careful planning and measurements will allow this engine to run happy for a long time.

[@Zincaloom]

The heads and yellow zinc plating look great. Can’t wait to hear and see it run.

[@GarageTimeAutoResto]

You and me both!

[@vaughnandrako6862]

Blueprint level measurements and assembly. Thanks for taking all the time needed to explain the how’s and why’s of 911 top end precision.

[@GarageTimeAutoResto]

Thanks, I always overkill things that are new to me. The nice thing about doing this for myself is that I can overindulge on the details.

[@douglasmccowen27]

Once again, a great video, Tom. Are you able to post where you took your parts to be yellow/zinc plated?

[@ErrorMargin]

Great video, looking forward to the rest of the series

[@walterkucharski4790]

Another great vid thanks.

[@jockellis]

For some things we use Mitutoyo inside mikes that measure to four places in some places and Mitutoyo digital calipers that measure to 5/10,000. Looks to me we would be better using analog dial mikes. My fantasy is to have a 12-inch Starrett dial Mike. Don’t need it, just want it.

[@GarageTimeAutoResto]

I had to rotate the head and my head just to read the numbers ha ha. This would have been better and easier to do on a surface table with a nice height gauge. That's on my wish list

[@GreenVision1]

Great video! How much did it approximately cost you to machine all the heads?

[@GarageTimeAutoResto]

About $1200

[@GreenVision1]

@@GarageTimeAutoResto that sound reasonable, thank you. May I ask how much the whole rebuild ran you? Im asking since I have similar project 3.2 engine - wondering if it’s worth it

[@GarageTimeAutoResto]

Just a few gaskets, fuel lines etc. maybe $1600?

[@jeffharrison5265]

Interesting tool to measure the volume. I'd never seen that done before. Great work. Where did you have the anodizing done?

[@GarageTimeAutoResto]

Yellow zinc chromate by Cadillac plating. They do all my engine test stand rings too.

[@jeffharrison5265]

@@GarageTimeAutoResto good to know. Lots I need to have redone.

[@GarageTimeAutoResto]

Let me know if you want to tag on to my regular parts lot. It saves money to combine and meet the minimum lot charge

[@jeffharrison5265]

@@GarageTimeAutoResto thanks.

[@tedman510]

Nice work, Tom. I've a 616/36 912 engine to be reconditioned for my 356. I'm wondering if you would you also consider S-tec a capable machine shop for Porsche push rod motors, both case and heads?

[@GarageTimeAutoResto]

Yes, they do machine work for many of the local 356/912 shops near here. I would recommend them. Contact Sheldon and talk with him.

[@Wanix11]

I didn't understand the word for the solvent for removing of the carbon because I am German. Please tell me.

[@Zincaloom]

I think he referred to Berryman’s Chem dip. It is a brand name carburetor cleaner.

[@GarageTimeAutoResto]

Correct, Berryman's. It's safe for all metals, but it does eat carbon. Sorry I don't know the active chemical that makes it work, but it's been around forever. I hope you can find something similar in Germany.

[@MH-ev3wr]

Hey Tom, do you need to use different metal gaskets between the cam towers and the head to account for the difference caused by machining?

[@GarageTimeAutoResto]

No gaskets are used between the heads and the cam tower. I'm not aware of any gasket that is .0004" thick. Paper is .003" The best we can do is measure and sort the parts for the best fit. After that the parts will mush together and be one happy engine I hope. Metal definitely moves.

[@MH-ev3wr]

@@GarageTimeAutoResto bah, yes! Sorry, I meant the heads and the cylinders.

[@GarageTimeAutoResto]

@MH-ev3wr oh, no gaskets there either on my engine. There are base gaskets that go between the cylinder and the case.

[@Porsche_Fan_3.2]

Hey new subscriber, I noticed you did not dig into the pistons and cylinders. Did you check those and just decide to leave alone? Thanks

[@GarageTimeAutoResto]

Thanks for subscribing! This is my own car and I had the leak down and oil consumption results before I took it apart. Nothing indicated that the pistons/cyl/rings were bad. A shop would mostly likely would have replaced them, but knowing how this cars is used I'm confident I can get another 10 years out of these. A tinker like me can take more risks than a shop

[@Porsche_Fan_3.2]

@@GarageTimeAutoResto thanks for responding, your videos are great and I am contemplating tackling my 3.2. 115,000 miles and has started to smoke! I have access to the special tools but will need a better torque wrench. They are expensive!

[@GarageTimeAutoResto]

Does it smoke while decelerating? Or startup?

[@Porsche_Fan_3.2]

@@GarageTimeAutoResto it starts up fine with not much smoke but then after about a minute the idle goes down and starts smoking pretty bad embarrassing white smoke. Once I get it running and fully warmed up the smoking clears up some but still there. I did put a bypass pipe on it and a Steve Wong Chip recently so I am sure that did not help. I have decided to tear into it and am hoping I will only have to go to the point you did in yours. I did note I have the mahle cylinders so that is good I think. the car is an 86 coupe. I might have someone folks come over and have a look at the P&C's when they are exposed. I am looking forward to working on it, thanks for the videos they help big time.

[@GarageTimeAutoResto]

Are you sure there isn't too much oil in the tank?

[@therealbarnekkid]

I'm impressed that these don't use head gaskets.

[@GarageTimeAutoResto]

Correct, no head gaskets. One of the reasons for all the tight tolerances.

[@williamfisk4841]

What valve springs do you use.

[@GarageTimeAutoResto]

These are stock Porsche springs. My other 3.2L engine in MAC uses AAsco springs and titanium retainers.

[@matthewsciarrotta2118]

Did you inspect all 6 x each port?

[@GarageTimeAutoResto]

Inspect all 12 valve guides? No

[@matthewsciarrotta2118]

Thanks - Looking forward to assembly@@GarageTimeAutoResto

[@bwj1158]

Is there a reason why you didn't rebuild your heads instead sending them out. It seems like a simple procedure. Would you recommend a novice that has never rebuilt a head and does not have the tools yet DIY? Which is cheaper?

[@GarageTimeAutoResto]

I did this for fun and as a challenge to keep my build under $10k. It's better to take it to a machine shop that does these all day long. Are you in socal? I can recommend a few

[@bwj1158]

@@GarageTimeAutoResto I'm in Alabama.

[@GarageTimeAutoResto]

@bwj1158 I don't know anyone there. Probably best to send out to the West coast

[@douglasmccowen27]

Just saw the comment reply below. Thanks.

[@saratoga123321]

Only since you said 5angle like a ton of times, you ought to have looked at Dave Vizards Cylinder Porting head guide. Proof is in the numbers that while 5 angle jobs have their niche and sound fancy, they’re arguably the worst for say your streeter here. An earnest piece of advice….

[@GarageTimeAutoResto]

Thanks, I'll look into his work a bit more. He seems to be a v8 guy with and dealing with shrouded combustion chambers. 911 heads are hemispherical. I don't understand how softening the edges of a three angle valve is bad for a street engine. It's not that fancy, it's just easier to do now with single point cutters. Why not get more flow if it doesn't cost more.

[@marklangren3142]

Didn't do a three angle valve job

[@marklangren3142]

Never assume unless you want to be an a**