964 Engine rebuild questions

[ALEX P]

Hi Steven, thanks for your post - you have PM.

[Trophy]

PM Replied

[ALEX P]

993 heat exchangers won in the end due to price and availability so I'll base my new exhaust project around those & if they don't work then I'll just have to have another rethink.

New exhaust here for anyone still awake!

My Ti exhaust project

[ALEX P]

This is a bit of a cross post as I know different people read this forum:

I don't know a great deal about exhaust design so I would appreciate a bit of advice from any of the knowledgeable folks on here who do

Because 993 heat exchangers exit facing each other I was planning on adding my 'X' pipe because it is already made and it is easier than manufacturing tubes crossing over each other. These then loop back round into the muffler where the left and right meet again internally.

My question is: Is this a bad design - Is it 'disruptive' to the pulses?

I don't want to go to the trouble and expense of making it if it is fundamentally floored. In an ideal world the 993 heat exchangers would face outwards and I could have a simple 'U' pipe into the muffler - I've even considered fitting the heat exchangers on the wrong way round but don't think they'll fit!

Exhaust design is like this:

[ALEX P]

993 heat exchangers fitted



Silencer & pipework fabbed



Bumper modified & tips made from Corvette exhaust

[brp914]

Can someone tell me how to get the harmonic balancer off? I ordered the extractor bolt from Baum, but it will take weeks to arrive. So I tried a 3-arm puller. I cranked it hard. It didn't work and actually bent the pulley. I assume the 10 bolts hold the balancer together and don't connect the balancer to the crank. So I left them there. Is this right?

It makes me wonder if the extractor bolt will do the job. And I can't get this Exxon Valdez engine apart w/o taking off the balancer because the A/C mount is behind it

Originally Posted by ALEX P

After speaking to a very experienced engine builder, he recommended that because I've got a new harmonic balancer and new (Patric motorsports) flywheel I should probably get the whole lot balanced, whether that was done seperately or as an assembly I don't know but I'm glad I did as they had to take a reasonable amount from both the flywheel and the harmonic balancer as shown below.

[ALEX P]

Originally Posted by brp914

Can someone tell me how to get the harmonic balancer off? I ordered the extractor bolt from Baum, but it will take weeks to arrive. So I tried a 3-arm puller. I cranked it hard. It didn't work and actually bent the pulley. I assume the 10 bolts hold the balancer together and don't connect the balancer to the crank. So I left them there. Is this right?

It makes me wonder if the extractor bolt will do the job. And I can't get this Exxon Valdez engine apart w/o taking off the balancer because the A/C mount is behind it

I didn't use the porsche tool but tried bearing pullers and all sorts with no luck at all.

It is on a taper and mine had a small patch of corrosion on it so was completely seized.

I eventually removed it with a hex head bolt which I think was M14 x 1.5 and a piece of steel bar of smaller diameter behind it cut to the right length. This is pretty much the same as the Porsche tool which is essentially just a bolt with the threads turned off. Using this method you just tighten the bolt in and it pushes the pulley out.

One piece of advice I would say is to make sure you have enough of the M14 x 1.5 threads engaged as you don't want to strip these!

It was a very happy moment when it eventually went with a pop. Small victories and all that!!


If you need more detail, let me know.

Good luck!

[brp914]

Thanks so much. My engine was actually shipped over from England. The tinware is kaput - I'm sure I've corrosion going on here too. But, what are the 10 bolts on the pulley for? Do they need to be removed to get the balancer off?

[safe]

Originally Posted by brp914

Can someone tell me how to get the harmonic balancer off? I ordered the extractor bolt from Baum, but it will take weeks to arrive. So I tried a 3-arm puller. I cranked it hard. It didn't work and actually bent the pulley. I assume the 10 bolts hold the balancer together and don't connect the balancer to the crank. So I left them there. Is this right?

It makes me wonder if the extractor bolt will do the job. And I can't get this Exxon Valdez engine apart w/o taking off the balancer because the A/C mount is behind it

Have you tried a hammer?

[ALEX P]

Originally Posted by brp914

Thanks so much. My engine was actually shipped over from England. The tinware is kaput - I'm sure I've corrosion going on here too. But, what are the 10 bolts on the pulley for? Do they need to be removed to get the balancer off?

The tinware is often kaput, worst areas are usually the LH rear and side tray by the catalytic converter. It is not cheap to replace either unfortunately. I replaced mine with fibreglass so that it would not rot again.

I wouldn't undo or remove the bolts. Even if you take them all out you still won't be able to remove the pulley so your best bet is to persevere. If it is anything like mine then all you will do with a hammer is damage the pulley and they are $$$ to replace unless you find a good used one.

They are also a balanced unit (hence why they have a varying amount of holes drilled in them) and they vary from car to car.

The Porsche tool or a makeshift version using a bolt with a machined down shoulder or a piece of bar to tighten the bolt onto is the easiest and best way to get the job done.

If you put some steel bar into the bore/hole so that it sits a few threads in from the pulley then get an M14 x 1.5 bolt and tighten it down onto the bar then it should break the seal and the pulley should pop off. If it squeezes the bar and compresses it then you can always add a spacer or slightly longer length in there making sure you still have good thread engagement like I said before.

Does any of that make sense?

[ALEX P]

Originally Posted by brp914

Thanks so much. My engine was actually shipped over from England. The tinware is kaput - I'm sure I've corrosion going on here too. But, what are the 10 bolts on the pulley for? Do they need to be removed to get the balancer off?

Just saw this over on the other channel:

Custom Crank Pulley Tool - Rennlist Discussion Forums

Nice and simple but as I said you can just use a bolt & small length of spacer bar.

[brp914]

Thanks. I wish I could machine a tool like that. My first thought was to fashion a bolt and an extension like you suggest but 14mm bolts are not easy to find. I had to modify a 3 arm puller to try to remove the balancer and that didn't work and bent the pulley, so I'm in no mood to fashion any tools.

How important is this balancer anyway? Clewett sells a serpentine system to replace the balancer. I assume it's only a pulley and not a balancer. Our host wants $1500 for the balancer. Which way to go?

[ALEX P]

Originally Posted by brp914

Thanks. I wish I could machine a tool like that. My first thought was to fashion a bolt and an extension like you suggest but 14mm bolts are not easy to find. I had to modify a 3 arm puller to try to remove the balancer and that didn't work and bent the pulley, so I'm in no mood to fashion any tools.

How important is this balancer anyway? Clewett sells a serpentine system to replace the balancer. I assume it's only a pulley and not a balancer. Our host wants $1500 for the balancer. Which way to go?

Just order the bolt from the internet or ebay if there's nowhere close to you that sells them. Maybe metric bolts are harder to source in the US.

A lot has been written about the 964 harmonic balancer and crankshafts potentially snapping without them. A lot of pepole don't run them but personally I re-added it as I figured it wasn't worth the risk - Porsche didn't put it there just to look pretty!

$1500 is nuts, just put a wanted ad on Pelican. I just did a quick search and found two for around $100 each. That's how I found & bought mine.

964 Harmonic Balancer

FS: Leftover 3.6 engine conversion parts (exhaust, pulleys, heat crossovers)

[earossi]

Originally Posted by Spenny_b

Hi Alex, sorry can't be of any help with your questions, but like you, I'm working my way through Waynes excellent book in anticipation of getting a particular 964T that I have my eye on, that's probably in need of a rebuild...up to Chapter 5 so far ;o)

Did you establish whether or not your crank journal measurements are in accordance with earlier <89 specs?

Does anyone know if Wayne is planning on updating the book for 964/993 owners?

Anyway good to know that somebody pretty local to me is also taking the brave pills and having a go themselves (...ie, I may well be in touch at some point in the future!!)

Cheers
Spencer

Hi Spencer,

I recently completed a total rebuild of my 3.6 motor out of my 1998 993. I used Wayne's book pretty much as my bible. For dimentional information not contained in Wayne's book, I relied on the Porsche Reference Guide data book for the 993. These little books are expensive (about $40), but essential for dimentional information.

In answer to your question about doing an update of Wayne's book to include the 3.6 motors, I sent Wayne an email with exactly that question. His answer was that he was not planning on editing the book for the 3.6 since these motors and the cars they came in were relatively low in number as compared to other 911's.

[earossi]

Originally Posted by Spenny_b

Hi Alex, sorry can't be of any help with your questions, but like you, I'm working my way through Waynes excellent book in anticipation of getting a particular 964T that I have my eye on, that's probably in need of a rebuild...up to Chapter 5 so far ;o)

Did you establish whether or not your crank journal measurements are in accordance with earlier <89 specs?

Does anyone know if Wayne is planning on updating the book for 964/993 owners?

Anyway good to know that somebody pretty local to me is also taking the brave pills and having a go themselves (...ie, I may well be in touch at some point in the future!!)

Cheers
Spencer

Originally Posted by ALEX P

Hi Spencer, I'll find out the differences between the earlier specs in the book and the 964 at the weekend and let you know.

I am tempted with the titanium jobbies just not the extra $300 or so! Then it's a case of which ones to go for as there seems to be quite a few to choose from.

I think I'm going to tackle the rebuild in two parts and concentrate on the bottom end first then when it's all together start looking at the top end as that's where all the real tuning options seem to be depending on the size of your cheque book!

Nobody got any advice on my case studs??

When I did my 993 at 110,000 miles, the studs looked pristine. Yours look to be far less than pristine. I would replace them. The cost to do it at this stage of disassembly is very low and so much easier to do then when one or more break with the motor in the car. Any stressed stud that has corrosion on it should be replaced since there is no way to determine the extent of intergranular corrosion and its impact on integrity. Just my humble opinion.

[porschetub]

Originally Posted by ALEX P

Thanks a lot for the advice Mike, I'll have a think and see if I want to play the risky CR gamble or take the safe but expensive JE route.


Scott Winders - Dude, there are some things you should write and there are some things you should just keep to yourself.

Well said,theres always one out there,if we didn't ask questions and make comments would forums work....not likely,some appear to not see it that way,as a wise man said,"there is no such thing as a dumb question only dumb people that don't ask them'',good luck with your project and well done I can tell you are on the right track.

[ALEX P]

Since my exhaust project has been completed the car now runs a bit rich - No real surprises as switching from 1.75" dia headers to stock 993 heat exchangers and completely different mufflers there was always going to be a knock on affect and the car was always going to require a remap.

So, I've got my car booked in to be have the map re-tweaked for the new exhaust and (in my mind) I've always planned on swapping out the injectors at the same time. My rationale for doing this is that last time the car was on his dyno in Dec 2011 it was making 308.2bhp and the stock 964 injectors max out at around 310bhp so they are operating at pretty much at their limit.

I've read countless threads about injector swaps and some people swap them for the 'big green' Bosch 0 280 155 968 injectors so armed with limited knowledge I was simply going to do this however the guy mapping my car said don't do that - they are way too big, almost twice as big as I need. Go for some stock 993 injectors or go for some BMW M3 injectors as the stock ECU only has 8-bit resolution on the injector outputs so you only want injectors in it that are big enough, not too big.

I know that 993 injectors was probably the sensible route to go but I've since bought some BMW M3 injectors and am about to get them cleaned and refurbed but was just wondering if anyone else here has run them?

[preston_brown]

I have a bigger motor than you Alex, but if you are re-mapping things you should be pretty safe unless you go crazy. Agree that the big greens are probably just too big. They are 440 cc/min @3 bar. I used Bosch 0 280 155 831 which are 300 cc/min @3 bar. Stock 993 injectors are 233 cc/min @3 bar.

The 300cc injectors are originally for Volvo apps, are a modern EV6 body with 4 hole cap. They should drop right in... but definitely will need to re-map.

[ALEX P]

Originally Posted by preston_brown

I have a bigger motor than you Alex, but if you are re-mapping things you should be pretty safe unless you go crazy. Agree that the big greens are probably just too big. They are 440 cc/min @3 bar. I used Bosch 0 280 155 831 which are 300 cc/min @3 bar. Stock 993 injectors are 233 cc/min @3 bar.

The 300cc injectors are originally for Volvo apps, are a modern EV6 body with 4 hole cap. They should drop right in... but definitely will need to re-map.

Hey preston_brown, thanks for the reply. I've read a couple of your posts when sifting through injector info about yours (3.9 race motor right?).

The injectors recommended were E36 M3 / E34 M5 injectors # 0 280 150 701
I've actually got # 0 280 150 792 also from E36 M3 Evo but should be about the same (245cc/min).

The advice I was given was that stock 964 injectors are around 200cc/min, so jumping up to 440cc/min (big green) is way too much because you're getting less than half of the accuracy. The E36 M3/E34 M5 injectors are around 250cc/min, so with 25% more flow available they won't top out until well beyond 350bhp, and very few 964s make that without considerable modification and expense. They also have the right conical spray pattern for my ports, unlike the 'twin-bent-spray' injectors designed for two intake ports of a four-valve head design.

I just find it interesting that there is not more people doing this or more info out there. I still can't find a comparison to compare all the injectors I considered.

0 280 150 731 (964)
0 280 150 786 (993)
0 280 150 701 (E36 M3)
0 280 150 792 (E36 M3 again)
0 280 155 968 (Big Green)
0 280 156 280 (Alternative to big greens)
and now
0 280 155 831 (Volvo)

Frustratingly the one I'm struggling to find all of the info about is the one that I've got which is the 0 280 150 792. I need to be 100% that it's ok before getting them refurbed. There's a lot of conflicting info out there! This one is quite good though:

Stan Weiss' - Electronic Fuel Injector (EFI) Flow Data Table

[safe]

I have 440 cc injectors in my 260 hp 3.2. Way to big, but it works.
For my 3.6 964 engine I just bought 6 of the Volvo injectors, I think they will be nice.