Aurel`s engine rebuild thread

[Aurel]

I retightened all the heat exchanger bolts, and I still have that exhaust leak. It seems to come from drivers side, and I could feel hot air blowing from the heat exchanger. I am wondering if one of the heat exchanger headers broke from the motor resting on it at some point?? This is a long week-end, so I am thinking about removing that passenger side heat exchanger to take a closer look at it.

Aurel

[Aurel]

You guys were spot on: you can see on the picture below where my clapping sound was coming from. Now, I need to figure out why that happened, and how to fix the issue...the bolts were tight, but maybe surfaces were not flat enough.



Aurel

[efhughes3]

Hmm, you had your heads done, correct? I'd of thought they'd check the surfaces, but maybe not. The only thing I can think of, if there is an issue with mating surfaces, and the nuts were tight, is maybe double up on the gaskets? I'm sure someone with better ideas will pipe in on this.

[Aurel]

Problem solved. It was the heat exchanger flanges that were not flat. A flat file took care of it, no more exhaust leak.

Before:

The fix:



Aurel

[otto in norway]

Nice job...!
But why have they become warped?? Any idea?
-wierd...

[Aurel]

30 years of heat cycling and corrosion, I suppose...

Aurel

[sabeo.m]

Aurel, glad to hear it worked out! I'm sure once I start putting stuff back together I'm going to be running into little mishaps. Nice video BTW!

[Aurel]

How does it sound now? For some unknown reason, the warm start problem has gone away, but I am still going to replace the fuel accumulator and the fuel filter that I already ordered.

Aurel

[efhughes3]

Much better!

[Aurel]

Originally Posted by efhughes3

Much better!

Thanks Ed,

What did you end up doing about your cam tower leak?

Regards,

Aurel

[sabeo.m]

Sound's nice and smooth, congrats!!

[efhughes3]

Originally Posted by Aurel

Thanks Ed,

What did you end up doing about your cam tower leak?

Regards,

Aurel

I've not touched it yet...it really is minimal, but it is there none-the-less. I'll probably pull her later this year, maybe around Christmas time. I'm too busy learning the twisties here in California.

[otto in norway]

Sounds excactly like I remember mine did before..!
Enjoy!

[OldTee]

Aurel
What little tips can you pass along for the benefit of the non professional engine builder? Sounded good.

[Aurel]

Originally Posted by OldTee

Aurel
What little tips can you pass along for the benefit of the non professional engine builder? Sounded good.

Well, I hope it will keep sounding good for a long time, and also push strong .

Some advice that comes to mind:

-Take your time, enjoy the process and the learning experience.

-Use this board, and the search feature. 95% of the time, someone has run into the exact same problem you have.

-Take plenty of pictures, especially all angles of your motor before you start unbolting things (CIS in particular).

-I should have used heat to remove my piston wrist pins, they are a little tight sometimes.

-Get the right tools, they make your life so much easier. Two that I found very useful were the carfstman bolt extractor kit that I used on my headstuds, and the 13 mm articulated socket for the heat exchanger bolts.

-Use powder coating instead of HT paint on your sheet metal. I just discovered my HT paint gets dissolved by fuel .

Aurel

[Aurel]

I took her for a 20 miles drive this morning, half highway, half small roads. The outside temps were very hot, ~ 95F. The motor temperature went barely over the mid-mark, oil pressure was fine, engine sound good, idles well, restarts well when hot now. No smoke too, which is a big relief as I rerung alusil cylinders, and it looks like the rings are sitting properly.

The low rpm torque is good. My only concern is that the engine is less happy revving than before. It does not feel like it wants to jump to 6k rpm as it it used to. I did set my cams (DC15) at 2.0 mm, that is the most advanced of the range (1.8-2.0 mm). It almost feels like I would never hit the rev limiter with that setup. That is a bit more boring that I wanted...I wonder if playing with ignition advance and waiting for the motor to totally break-in will make a difference. Otherwise, I may have to retime my cams at some point...

I just have one question for the experts: Is there an easy way to predict how many rpms the max power band is shifted if I retarded my cams to 1.8 mm instead of my current 2.0 mm setting ? Would the difference be noticeable?

Aurel

[Aurel]

I experimented a little more with ignition timing tonight. At 0 deg, the car is a dog, wrong direction. So I went a little past 5 deg, maybe 7-8 deg, and it seems to really pick up more rpms. The cam timing is probably OK, but the ignition needs to be a little more advanced than factory. How far can I go is the question. I`ll leave it as i for now. I haven`t measured the timing at 6000 rpms, I think 35 degs is the max allowable.

Aurel

[Mr.Puff]

Nice thread bud.

[Aurel]

Originally Posted by Mr.Puff

Nice thread bud.

Thanks !

I`ll try to update every once in a while on how the motor breaks in, then how long the alusils last...
I get a little puff of smoke at startup, but it clears out immediately. Its a Porsche! I am still using 10W30 for the break in (flows so much better!) but I will switch to 20W50 for my fourth oil change.

I took her to work yesterday, 60 miles round trip with some idling in traffic. No problems!
She stays much cooler than she used to. I still need to check my total advance at 6000 rpms. John says 32-34 deg BTDC should be good. Right now, I can tell the motor is not giving all it could.

The rebuilt gearbox is also a joy to use, no more noises, 1st and 2nd engage without giving a fight. Third is a little hard to engage, but it`ll break in. In the interim, a little throttle blip in neutral works great.

Aurel

[Aurel]

Car is still running good!
I`ve uploaded all the pictures taken during my rebuild in google Picasa:

http://picasaweb.google.com/ad8588975/30LRebuild

Aurel