new to forum - doing top end rebuild on a 3.2

[hcoles]

Hello People - I have an 1989 Carrera with 76k miles.

Current status - engine out and down to the p's and c's still attached.

There are some reasons I'm doing a top end rebuild:

- pulled the exhaust manifolds off and there was a lot of carbon build up on about 4 of 6 cylinders

- the idle is not real smooth, sort of bumpy most of the time.

- since I got the car 4 years ago there has been a ticking noise when the engine gets warmed up, I was hoping to find an exhaust path leak of some type that might provide an easy fix. no such luck....I sure hope it is something with the valves.

- I really like working on mechanical things and have done most of my auto repairs over the years.

The people in PCA in my area haved helped me decide to dive in and do it myself. Of course I have Wayne's book and have been reading and rereading it.

The cylinders are Nikasil (sp?), my inclination is to take the pistons out of the cylinders and look for any issues. A number of people are saying to leave things alone....the p's and c's are fine.
I didn't do a compression test before, and there hasn't been a lot of oil useage. From what I can see of the cylinders they have most if not all of the original "honing" marks. So the questions to the group...take things apart with the associated risks (scoring a rod bearing, breaking a ring during reinstall) or leave alone. I can't tell if the cylinders are glazed or not....I've cleaned the top of the cylinders a bit with a Scotch bright pad to try and get most of the carbon off.

I'm planning to replace all the head studs with steel. The bottoms are Dilvar and some of the tops are a bit rusty looking. A person is going to help with the studs and can do it with the pistons still attached to the rods/etc. and cylinders on the pistons.

Another question - replace cam chains or leave as is? I'll put in new ramps.

Two of the cylinders look like they were running lean...I'm considering sending the injectors out for checking and cleaning. Any comments on this or places to recommend? I know EBS does this.

Another....I'm considering going to a "964" type cam via regrinding...any comments on this...the rockers are being squared along with the head work. I'm not planning to change the "chip" or other engine mods and I usually run with a test pipe. I use the car for daily driving and AX maybe 15-25 times a year (my son and I both drive it)

Wayne recommends updating to the more restricted oil fittings for the cams....I'm sort of getting mixed comments from others on this.

I guess this is about it for now....I'll see what sort of comments I get back.

I think it is a wonderful thing that Wayne has put so much effort into the Porsche books. I also want to thank all that have been loaning me tools, providing moral support and technical input.

Thanks,
-Henry

[hcoles]

Noah,
Thanks for the reply.

The chip is stock. I usually run the 91 oct fuel available in CA.

Would you still suggest a Steve Wong chip?

The plugs on the lean cylinders, if I remember correctly, look a bit whiteish compared to the others but I need to double check that. I'm just worried that the injectors are not all matched after running for 17+ years and probably not being checked out.

I might just track the car for one or two DE events per year. When I do I usually short shift the car most of the time. The mechanics around here (San Jose CA) do acknoledge the small rod bolts but don't remember any engines breaking any.

I will probably go in the direction of leaving well enough alone on the p's and c's and not even pull them off the engine. This assumes I can change the head studs with them in. It sounds like it is ok to clean with alcohol and scrub pad, maybe I can do this and send out a picture or two.

I'm just hoping to get the engine back together not leaking and running smooth as it should be..

Is there a top 10 list of things people make mistakes on when rebuilding a 3.2 somewhere on the site? I plan to follow Wayne's book to the letter but it might be nice to have a key "hit" list. e.g.
- clean parts
- clean parts
- clean parts...esp. from oil pump to oil into bearings
- assembly sequence....heads and cam towers
- torques
- start up and run in processes
- don't leave off starter ring gear
- don't leave off clutch fork
- replace front and rear main seals, be sure to lube these
- use assembly lube...

Thanks for any input.

-Henry
89 Carrera - forest green

[addictionMS]

check out

here

and

here

[Bill Verburg]

Another question - replace cam chains or leave as is? I'll put in new ramps.

If you replace the cahains also replace the gears, they generally wear together.

look at the gear teath carefully, they should be symetric, if they have a curved or hooked appearance then they need to be replaced.

These have just barely started to wear

[hcoles]

Bill,
Thanks, that's a good point.

Also, one thought I heard was that as the chain wears the pitch of the chain increases and the pitch of the sprocket doesn't.

So I'm thinking that running with an old chain and old sprocket could be worse than a new chain and old sprocket.

Of course new and new would be the best.

Another tip I got yesterday from Don Wise. Look at the wear pattern on the sprocket and see if the chain is running in the middle. This is why there are cam end play shims.

Along the same lines...it is interesting that the cam chain tension side is on the same side as the tensioning system. One might expect it to be on the other side as most cam chain and belts on other cars. What is the story behind that?

I appriciate any and all comments to my post. I'm learing more everyday and doing all sorts of searches on this website to get answers.

-Henry

[hcoles]

Here are pictures of a cylinder, this is typical across all holes.
I'm asking for comments, right now I'm leaning toward going to JWE and getting an evaluation to hone and rering or just clean and reuse. These are from an 89 3.2 with 77k, of course they are Niks. Cleaned with alcohol and Scotchbright. I'm looking for a ticking noise in the engine when it is warmed up. Valve guides looked like they needed rework as well. The heads are over at Teds (German Precision).

Also added an interesting picture of an e-foot.

Thanks for all the comments.

-Henry

[hcoles]

Here is a picture of vert. lines in cylinder #3

[hcoles]

The light vertical marks turned out, I think, to be chunks of carbon rubbing up and down while they were figuring out a way to get out. I don't think there is any cylinder material disturbed.
IMHO
-Henry

[hcoles]

Question: replacing rod bolts without spliting the case??? I assume I should use the "bolt streach" methode to torque the nuts, is there room for this? Suggestions on hardware? Thanks.
-Henry

[addictionMS]

I don't think you will be able to measure stretch, there is not much room in there, I think just getting the bolts back on will be hard enough.

Be sure to have one of those magnet tools to pick up the nut after you drop it in the case, it is bound to happen

Jim

[dickster]

henry,

its hard to tell from the pics (wrong angle of the bores) but it looks as though you may have some wear. while you have access it would make sense to try a dial indicator/gauge (?) in the bores to check that they are round. any wear will show up as an "oval" bore.

[hcoles]

P's and C's are now over at JWE being eval. and re ringed. I assume they will check the bores for roundness and taper.
-h

[hcoles]

3.2 top end update...

Things are going ok. Heads and P's and C's out being done/inspected.

Current plan is to replace all head studs with new stock steels.

Been thinking about the oil line restrictions mentioned in Wayne's book. All (most all) the mechanics I talk to know about it but are not putting them in as a usual practice. I figure Wayne didn't put this out casually. One thought....if putting the restrictors in moves the risk toward top end failures and safer bottom end...then it could definately be the thing to do. Bottom end issues are $$$$, top end issues seem to be $$. I heard from one mechanic that if the engine is going to be a race engine then he wants them to be in.

Wayne - are people putting these in, for street and ax, and you are still not seeing top end problems reported? Just wondered if there was any update on this.

Trying to find a reasonable way/place to calibrate my two torque wrenches in/near San Jose CA. Now thinking of the Snap-on guy or sending to Girots if I don't find a reasonable place. Most of the places that come up on Google are official and certified and provide a paper trail and all of that...I just want to make a conversion chart or wrench clicks at XX.X and actual reading was YY.Y. and then do my own math for engine assembly.

I started making a task list before doing the top end assembly and got depressed because it is so long....started with getting the torque wrenches calibrated.

I have some more pictures of carbon on the side of a piston and will post if people want. The valve guide issue and then generating all this carbon really doesn't seem good. I hope the engine runs much cleaner for a long time after all of this is done.

I guess that's about it for now.

Would it have been better to start a new thread asking just re. the oil restrictors?

Thanks for all the input and comments. Camgrinder, Jamie et.al. have been great.

I still feeling about chest deep.

-Henry

[galwaytt]

Originally posted by hcoles
....
Trying to find a reasonable way/place to calibrate my two torque wrenches in/near San Jose CA. Now thinking of the Snap-on guy or sending to Girots if I don't find a reasonable place. Most of the places that come up on Google are official and certified and provide a paper trail and all of that...I just want to make a conversion chart or wrench clicks at XX.X and actual reading was YY.Y. and then do my own math for engine assembly.

unlikely that any calibration lab will 'just' do that for you, and in truth, there shouldn't be any need to do calcs. Besides, because a torque wrench has a range to cover, you could well find the calculation being different from one end of the torque range to the other...........extreme case, but it happens.

Now - do you know anyone who works in an aerospace or automotive plant? They all have torque testers, and they should be able to 'help' you if you just want readings........

In San Jose, try MOUNTZ

or, you could try these guys, if you're willing to post the tools.... AIMCO


I've dealt with both.

[hcoles]

From Bill Verburg,

If you replace the cahains also replace the gears, they generally wear together.

look at the gear teath carefully, they should be symetric, if they have a curved or hooked appearance then they need to be replaced.

I looked at the sprockets last night and they are worn on one side a bit and not on the other....so I guess the sprockets are not running true with the chain. Assuming that this was last touched at the factory (76k miles) does that mean they didn't do a very good job? Is this common to see. I guess I'm going to be doing the sprocket offset process....I'll see if I can borrow one of those large straight bars....I have a digital caliper so that is about all I need I guess. Is there any ways to push the tolerances when doing the measurements? I think I saw a thread on that.

Thanks,

-Henry

[galwaytt]

Henry - any luck getting your wrenches done?

[hcoles]

No luck yet. There are plenty of places that will do it for $30 or $40 per wrench. I'm thinking of making a setup. I just want to get a chart of what my wrenches read and what the "real" torgue is. I'm not sure this is exactly what you get with the common services.
Thanks for asking. I'll probably publish an update on all the progress I've made in a week or so. I'm figuring I can start bolting things back together in about 1.5 weeks.
-Henry

[galwaytt]

Henry, unless you're wrench's are miles out, any 'rig' you set up isn't much help. The MOST accurate click wrenches on the market are within 3% - the vast majority are way worse than that...say 5%-10%......and that's using lab instruments. Quite how your 'rig' will improve this escapes me........unless you're using a digital instrument, you won't be able to accurately apply any small difference you note, even bearing in mind that the difference you 'measure' on your rig can still be out by 10%.....

Bear in mind they don't use click wrenches to build the engines in the first place................

For those with deep pockets, have a look here http://www.norbar.com/products_category.php?category_multid=8 on the perfect way to measure bolt stretch.

[hcoles]

Cam shimming to align with chains. I don't think the last person in the engine did this correctly....I think the last person in was the factory....

Here is a picture of a cam sprocket, it looks a bit worse that it actually is, in any case I don't think this cam is aligned good.

The second picture shows the back of the same gear, notice the original machining marks as the flat part goes into the tooth profile.

By looking, I don't think the root of the profile has much wear.

Comments?

[hcoles]

People may no longer be reading this thread. See the pictures above...I showed these and talked to two sets of people this morning....

1) even if you shim correctly this will always happen because when you accelerate the lay shaft moves over...this doesn't make sense to me

2) Oh yes those look like they need to be aligned better

I'm looking at getting the good straight edge and holder.

Comments?

Thanks,