3.0 SC High Performance Rebuid

[lindy 911]

Re-checked the valve cover and gasket and that's OK. Pulled the #1 intake rocker and reinstalled and that checked OK. I do have RSR o-rings installed on the rocker shafts. Since I have twin plugs, I pulled the lead to the top #1 cylinder so I could watch where the oil started from as I suspected the rocker shaft. I started the motor and watched. It is not the shaft but further up towards the head. Damn!

Looks like the cam tower is leaking at the head seal. I spent a lot of time with this part of the assembly and this really pisses me off because the only way to get to it is pull the motor back out. Oh well, I'm getting pretty good at it by now. I used 574 here. I know Henry suggests something different at the joint; I think I'll search his thread of ultimate seals.

On a brighter note and since the oil leak didn't seam catastrophic, I went ahead with the 25 minute break-in at high idle so I could use the remaining life of my break-in oil. As I said before, this motor is very quick to rev and has an awesome sound even with the stock exhaust. My headers are on the way and those will go on with the motor pull.

Lindy

[snbush67]

Lindy,

Could it be the cam shaft seal or gasket? Maybe the gasket caught an edge. Sorry to hear about your leak.

Shane

[lindy 911]

Shane,

It doesn't appear to be coming from the chain box gasket area but higher. When I pulled the top plug and ran it the oil came from above that joint and not the rocker shaft.

By the way and FYI, if you plan to renew the bushings in the throttle linkage bell crank located on the transmission, the procedure requires an engine drop or at least a partial. Ask me how I know.

Lindy

[juicersr]

Originally Posted by lindy 911

By the way and FYI, if you plan to renew the bushings in the throttle linkage bell crank located on the transmission, the procedure requires an engine drop or at least a partial. Ask me how I know.
Lindy

LOL, BTDT on that one. Looks like it would be sooooo easy from below, doesn't it!

Great work on getting motor running!!!!

[snbush67]

Originally Posted by lindy 911

Shane,

By the way and FYI, if you plan to renew the bushings in the throttle linkage bell crank located on the transmission, the procedure requires an engine drop or at least a partial. Ask me how I know.

Lindy

This is crazy! Late last night I was out enjoying my engine "breaking it in". About a block from home the left CV joint came undone, I had torqued the hell out of it but somehow the bolts backed out and one lone bolt sheered letting everything go.

So me in my moment of brilliance, decided to tie up the loose end of the CV so it wouldn't hit the ground. When I towed the car the rope caught the throttle rod and twisted it to hell and busted the throttle linkage stud on the bell housing and bent the crap out of the one in the carburetor manifold. All of my carb linkage is bent to ****.

Well, it was fun while it lasted! I really didn't want to hijack your thread but it is scary how you mentioned this.

Shane

[lindy 911]

So I guess I should keep the FYI about the crank and rods to myself?

Lindy

[snbush67]

Originally Posted by lindy 911

It doesn't appear to be coming from the chain box gasket area but higher. When I pulled the top plug and ran it the oil came from above that joint and not the rocker shaft.

When I did mine I used a scotch brite to clean the old sealant off. I used liberal amounts of 574. I brushed on 1/8" of sealant on all the head to cam-tower surfaces, I did have a couple of small scratches in places but nothing that would catch a fingernail.

At least you have been able to run the cams in and you know that the rest of the motor is sealed.

Also, I am not sure if it matters but I torqued the cam towers to the heads and then put the final torque on the heads to the case.

Hope this helps. Shane

[lindy 911]

Shane,

Thanks for the advice. I was talking to Arron at Rennwerks and he mentioned the same process. I re-read Waynes manual and it says the same. Gee, you'd think that I would have caught that. Oh well, good practice I guess.

Sorry to hear about your CV joint, I know I'm going to double check mine! Did you have a chance to see what your new motor is going to run like? I'll bet it rips.

Lindy

[snbush67]

Yes, it is scary I put about 100 miles on it yesterday, It is crazy fast and I havnt spun it over 5K, I am beginning to wonder what the hell I was thinking. It accelerates with some crazy G forces. I truly cant believe the power. Sorry I am rambling, but at first I had my timing way way advanced, the I figured out I had it 30 degrees advanced (I was using the wrong mark on the pulley even though I had marked it), its back down to 12 now and Wow!.

The other mistake I had made was I put my reverse pin back-wards and my lights wouldn't go out. And I had hooked my alternator up wrong, I have it sorted now. But I started rushing the closer I got and started going from memory rather than the book.

I had an experienced mechanic right with me during my build, so every time I got going he was there to check and provide guidance if not I probably wouldn't have got it done right.

Once I got the block back in my garage I started getting squirrly, my mind started swimming the closer I got to starting the motor, I was jumping from one thing to another, tinkering with somthing else, it was hard to focus.

If I did this again I would make a condenced checklist with step by step instructions on a huge poster board so I could put big checkmarks by each item as I completed it, and probably take a valium.

[lindy 911]

Turns out you were right. The gasket at the chain box got pushed out some how. I talked with Arron and Henry Schmidt and they both said this is not uncommon and that joint is under pressure from the cam oiling circuit which is why it was bleeding like a "stuck pig". Anyway, motor out, fix the gasket and install it correctly with a setting sealer like 574, re-time left cam and button it back up.

I'm waiting on my headers to show up before I put it back in the car. It just looks a lot easier to install them with the motor on the stand. I'll try to get some photos posted this afternoon.

Lindy

[juicersr]

Motor in yet?

Any plans on dyno tuning? Really curious to see what your numbers turn out to be.

[lindy 911]

Yes, motor went back in a couple of weeks ago. I discovered a couple of transmission issues that I think are relatively minor but we will have to see. I will have it dynoed for final tuning at Protechnik in Houston. It's fat now but it does run very well. I don't jump on first gear much but second without banging the clutch will light the tires. Granted; I have stock 7" Fuchs and looking for 8's but it spins the tires without trying. It is a little on the peaky side once past 4,000 but I like that. Below 4,000 you can't tell it's not a stocker unless you are in the vicinity of the muffler outlet. You can feel every cylinder fire.

I've only run it up to about 6,000 and shut it down because I ran out of road. It's not licensed yet so I'm somewhat illegal until I get it inspected and screw on the plates. Performance wise it's everything I hoped it would be to this point. I'm looking forward to the dyno numbers; whatever they may be.

Lindy

[lvporschepilot]

What length/mileage of break in process are you allowing for? Everyone seems to have their own voodoo.

[lindy 911]

I'm not a big believer in "break-in". When we were building race motors for motorcycles it was pretty much warm it up and run the hell out of it. Those were the motors that would win races. I'm going that route and if it doesn't work, oh well it's just a toy and I'll tear it apart again. I did do the 20 minute thing and then change the oil. All the moly lube when building it can't be too good for the cylinder / ring seating, so I dumped it and changed the filter. It was pretty ugly oil when it came out.

Lindy

[juicersr]

Originally Posted by lindy 911

I'm not a big believer in "break-in". When we were building race motors for motorcycles it was pretty much warm it up and run the hell out of it. Those were the motors that would win races. I'm going that route and if it doesn't work, oh well it's just a toy and I'll tear it apart again. I did do the 20 minute thing and then change the oil. All the moly lube when building it can't be too good for the cylinder / ring seating, so I dumped it and changed the filter. It was pretty ugly oil when it came out.

Lindy

+1. What i did on my SS build last year.

That engine bay has to put a smile on ur face.

[lvporschepilot]

Those of you who break in this way, about what were the leakdown numbers on your respective engines?

I guess I have been too paranoid with Ferrari engines to really tear into them right after the warm up. I run them for 20 minutes, drain the oil. Restart, go for a short easy drive (20-30 miles)staying below 5k constantly accelerating and decelerating so the vacuum wears in the rings a bit. Shut down and allow the engine to cool and go for another drive the following day, this time a little harder. Generally speaking I take it easy the first 200 miles. Always interesting seeing what others do and what they have success with.

[HondaDustR]

+1 on the running the hell out of it. I just got through refreshing a 944 motor and looked into that dilemma, including the epic Re-ring Alusils thread, and one of the articles was a back to back comparison of sport bikes broken in lightly "as per manufacturer's specification" and another broken in on the track...the track run one had better compression and maintained high compression longer in its life. At least for silicon/aluminum cylinder alloys like Alusil, they said most of the break-in, as much as 80%, will happen in the first 30-40 miles. Freshly lapped Alusil has exposed silicon particles that are "edgy" and give the cylinder surface extra abrasiveness needed for ring break-in. The particles dull, giving way to a smooth, durable surface. The running to hell ensures the rings are uniformly pressed onto the walls as they would be at full load and makes for a better fit so they don't just glaze in spots, and to ensure they break in all the way around within that "roughness" window. Hard on throttle to redline, then shut and let vacuum flush the cyls with oil. All I can say personally is it seemed to work really well for me...not the slightest bit of oil smoke and it runs strong for a mostly stock motor and still true after 6500 miles. Breaking in other types of cylinders/pistons may do better with different techniques.

I don't want to sound like the FOS water cooled guy butting in, but I was browsing the 911 rebuilds for fun and just wanted to share my 2 cents.
This forum is where all the cool projects are!

[lindy 911]

A few pics of new fiberglass stuff being fitted. What do you all think?

Lindy

[lindy 911]

Here are a couple from the rear.

[jmz]

I like the rear. Not so sure about the front.