Topend Refresh: the Good, the Bad and the Ugly
#1
Burning Brakes
Thread Starter
Topend Refresh: the Good, the Bad and the Ugly
Hi All
After lurking here long enough, I decided it was time to start transferring my years of experience working on my SAABs to my new 928. So, with massive technical assistance from my friend Worf, we have begun the topend refresh on my "low mileage" red GT.
The goal of this topend refresh is really just to make the car "safe." I am focusing on things like updating all the fuel lines with Greg Brown's newest kevlar reinforced design, chainging lots of rubber parts and updating the power steering hoses. This is a 20 year old car. So, let's not kid ourselves and do the basic maintenance...
The good news is that the block and cooling system seem to be in good shape, i.e. it looks to me like the previous owners took care of the car and at least changed the coolant regularly.
The bad new is I did find some pitting on cylinder 6's exhaust cam. See image below. One lob is starting to not look so good, and the other is really minimal. On the whole, it is probably not critical (yet) and the only action I am taking now is to put the Amsoil in and watch it for when I ever go under the cam covers again. The question is, where does this come from in such a low mileage car (under 40.000)? I did find a number of comments on this issue like:
Prevention Using the Right Oil: https://rennlist.com/forums/1700446-post26.html
Improvements by Changing Components: https://rennlist.com/forums/9236450-post26.html
The ugly news is that the intake manifold and the cam covers were in such bad shape that I shall certainly have to powder coat them. Somebody must have tried to clean them with some chemical which seems to have caused very rapid deterioration of the coating! I discovered that stripping is a real bitch! How are people out there stripping their parts? The picture below show how much could be removed from the intake manifold by just using "dental tools" with little force and much patience.
More later... But for the time being I have to finish stripping and then take the parts to an appropriate person for powder coating and get the rest of the parts to put everything back together! In the mean time, any comments about pitting on GT cams and stripping would be appreciated!!!
The thing that amazed me the most finally digging into this car, which I have owned for about a year now is the high complexity! Lots of parts and lots of electronics... Lots to learn about... :-) Lots to go wrong, if not followed regularly... :-(
Cheers,
John[ATTACH]Attachment 633585[/ATTACH]
After lurking here long enough, I decided it was time to start transferring my years of experience working on my SAABs to my new 928. So, with massive technical assistance from my friend Worf, we have begun the topend refresh on my "low mileage" red GT.
The goal of this topend refresh is really just to make the car "safe." I am focusing on things like updating all the fuel lines with Greg Brown's newest kevlar reinforced design, chainging lots of rubber parts and updating the power steering hoses. This is a 20 year old car. So, let's not kid ourselves and do the basic maintenance...
The good news is that the block and cooling system seem to be in good shape, i.e. it looks to me like the previous owners took care of the car and at least changed the coolant regularly.
The bad new is I did find some pitting on cylinder 6's exhaust cam. See image below. One lob is starting to not look so good, and the other is really minimal. On the whole, it is probably not critical (yet) and the only action I am taking now is to put the Amsoil in and watch it for when I ever go under the cam covers again. The question is, where does this come from in such a low mileage car (under 40.000)? I did find a number of comments on this issue like:
Prevention Using the Right Oil: https://rennlist.com/forums/1700446-post26.html
Improvements by Changing Components: https://rennlist.com/forums/9236450-post26.html
The ugly news is that the intake manifold and the cam covers were in such bad shape that I shall certainly have to powder coat them. Somebody must have tried to clean them with some chemical which seems to have caused very rapid deterioration of the coating! I discovered that stripping is a real bitch! How are people out there stripping their parts? The picture below show how much could be removed from the intake manifold by just using "dental tools" with little force and much patience.
More later... But for the time being I have to finish stripping and then take the parts to an appropriate person for powder coating and get the rest of the parts to put everything back together! In the mean time, any comments about pitting on GT cams and stripping would be appreciated!!!
The thing that amazed me the most finally digging into this car, which I have owned for about a year now is the high complexity! Lots of parts and lots of electronics... Lots to learn about... :-) Lots to go wrong, if not followed regularly... :-(
Cheers,
John[ATTACH]Attachment 633585[/ATTACH]
#2
Addict
Rennlist Member
Rennlist Member
They'll blast it; I think my PCers used aluminum oxide as the blast media. All I did to my parts before handing them off was a little crude power washing to get the worst of the grime and flaking paint off.
See Powder coating intake/cam covers/etc. best practices.
#3
Chronic Tool Dropper
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Your intake color is very typical of one that has had a cleaning with common cleaners/detergents. The first casual engine cleaning I did with a petro/detergent (Foamy Engine Bright by Gunk) gave me streaks of that color, even though I hosed it off mere seconds after I appled when I saw what was happening. After that, nothing stronger than a very dilute detergent avoided further damage. But the streaks were there. Ended up with PC in the original silver that seems to hold up better to more normal engine bay chems. I'm working to keep the look as close to original as possible.
#4
Rennlist Member
Hey, I recognize that bench your intake is sitting on! You are in great hands. Our cars are roommates at the moment. I was scared to death when we started taking mine apart; now not so much! Good luck with the refresh.
#5
I just stripped and painted my intake, used a product called D-Zolve 15-33LO-R Aircraft Approved Stripper, I called these guys http://solventkleene.com/strip.htm and they sent me a free sample.
Used a power washer to clean off the stripper and stubborn spots.
Used a power washer to clean off the stripper and stubborn spots.
#6
Burning Brakes
Thread Starter
Paul!
I'm glad you posted. I remember seeing your intake manifold and valve covers some place... Those are pretty much the colors I want to make mine!!!
What paints did you use for the black and red?! I think it would go well with my guards red on black (boring color scheme) 928.
BTW, I think that stripper was much more effective that what I applied on my manifold...
John
I'm glad you posted. I remember seeing your intake manifold and valve covers some place... Those are pretty much the colors I want to make mine!!!
What paints did you use for the black and red?! I think it would go well with my guards red on black (boring color scheme) 928.
BTW, I think that stripper was much more effective that what I applied on my manifold...
John
#7
Burning Brakes
Thread Starter
Ed, thanks also for that link on best practices. It looks like, I could have started off a little quicker... Why didn't I search for a thread like that earlier... !!!
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#9
I used testors black and red enamel paint markers.
#10
I just stripped and painted my intake, used a product called D-Zolve 15-33LO-R Aircraft Approved Stripper, I called these guys http://solventkleene.com/strip.htm and they sent me a free sample.
Used a power washer to clean off the stripper and stubborn spots.
Used a power washer to clean off the stripper and stubborn spots.
#12
Rennlist Member
Rennlist Site Sponsor
On my '90 GT, hand stripping the intake with plastic and wooden scrapers removed the top coat in about an hour and a half, with no glass beads or aluminum oxide left inside and in fastener holes to cause later engine damage. I then solvent cleaned and painted with molten silver wheel paint from a rattle can - looked pretty good then, still does a couple of years later.
#13
I used Duplicolor self-etching primer, Rust-oleum 500 degree engine enamel ( color aluminum ), and duplicolor clear coat. its only been a few months so no data on durability.
#15
Burning Brakes
Thread Starter
The reality of 20 year old cars...
So, progress is being made on my topend refresh.
In retrospect, I am a little bit surprised how involved the process has been. i started ordering parts in February, started taking apart in May, and hell, Summer is almost over!! This is the reality of owning a 20 year old car. Many surprises, even if the car was a good shape from the beginning.
But, I am happy with the results so far. I decided not to do the red/black lettering and just keep "stock-looking":
In retrospect, I am a little bit surprised how involved the process has been. i started ordering parts in February, started taking apart in May, and hell, Summer is almost over!! This is the reality of owning a 20 year old car. Many surprises, even if the car was a good shape from the beginning.
But, I am happy with the results so far. I decided not to do the red/black lettering and just keep "stock-looking":