Shaftless Throttle bodies
Hi everyone. Just thought I would register since Jason has been telling me all about this site. And since he’s a great guy I figured you all must be too.
As for the failure on my engine there were many leading up to the rod knock. I had 3 timing belt failures - the last of which resulted in $5k in head work because the shop who rebuilt the engine refused to fix it. The final timing belt failure was when I finished work and parked in my underground parking garage. Can ran fine when I parked it. But when I went down to start it the starter just freewheeled making a zing type noise - no compression. I knew something was wrong right away. So I had it towed to the local Porsche dealer to take a look. The engine was under warranty and I could have taken it back to the builder. But since this was the umpteenth time I had brought it back to them I decided I wanted a fresh set of eyes to look at it. So I called the builder and asked if he would want to come up and watch as we took a look. He said I would have to pay for his time. I was not happy about it but agreed and told him we were starting at 8 am. He never showed. I even paid for the Porsche mechanics to wait 2 hrs because he kept saying he was coming before finally saying he wasn’t. So we started without him. When they took the plastic timing belt cover off there was a timing belt pulley just laying there. The bolt had sheared off. Because the block was from an 86 951 and my oil pump was from an 1989 951 it was required to space the pulley out with a spacer. The dealership printed off the technical services bulletin showing the procedure. What the engine builder did was try and use a stack of washers to space it out. Which might have worked if they placed them in the correct place on the block side of the nut instead of the pulley side. What they did was bottom out the threads on the stud and then put the washers on to space out the pulley. The nut on the stud was not snug to the block - there was a small gap as there are not enough threads on the stud or the hole isn’t deep enough. This meant the stud could vibrate and experience metal fatigue. Would also explain why my timing belts kept walking off, shredding one side, before breaking - 3 times. I had bent valves and the repair cost me $5k at the dealership. It ran fine for another few months before I started hearing rod knock. After that I hauled the car home and has sat on my lift since then as the whole event soured me on the 951.
As for the failure on my engine there were many leading up to the rod knock. I had 3 timing belt failures - the last of which resulted in $5k in head work because the shop who rebuilt the engine refused to fix it. The final timing belt failure was when I finished work and parked in my underground parking garage. Can ran fine when I parked it. But when I went down to start it the starter just freewheeled making a zing type noise - no compression. I knew something was wrong right away. So I had it towed to the local Porsche dealer to take a look. The engine was under warranty and I could have taken it back to the builder. But since this was the umpteenth time I had brought it back to them I decided I wanted a fresh set of eyes to look at it. So I called the builder and asked if he would want to come up and watch as we took a look. He said I would have to pay for his time. I was not happy about it but agreed and told him we were starting at 8 am. He never showed. I even paid for the Porsche mechanics to wait 2 hrs because he kept saying he was coming before finally saying he wasn’t. So we started without him. When they took the plastic timing belt cover off there was a timing belt pulley just laying there. The bolt had sheared off. Because the block was from an 86 951 and my oil pump was from an 1989 951 it was required to space the pulley out with a spacer. The dealership printed off the technical services bulletin showing the procedure. What the engine builder did was try and use a stack of washers to space it out. Which might have worked if they placed them in the correct place on the block side of the nut instead of the pulley side. What they did was bottom out the threads on the stud and then put the washers on to space out the pulley. The nut on the stud was not snug to the block - there was a small gap as there are not enough threads on the stud or the hole isn’t deep enough. This meant the stud could vibrate and experience metal fatigue. Would also explain why my timing belts kept walking off, shredding one side, before breaking - 3 times. I had bent valves and the repair cost me $5k at the dealership. It ran fine for another few months before I started hearing rod knock. After that I hauled the car home and has sat on my lift since then as the whole event soured me on the 951.
Last edited by Soloracer on Sat May 06, 2023 11:51 pm, edited 6 times in total.
Found my receipt for the crank work. It was CMW Motorsports. I am still looking for the TSB to properly install an 89 oil pump in an 86 block. Will post if/when I find it
Here are pics or the timing belt pulley
Here are pics or the timing belt pulley
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Tom
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Hey Soloracer, it's tom m'guinn -- welcome aboard (and thank you Jason!). We're a good group and growing, without all the Viagra ads and bs you might find elsewhere. 
So are you done with 944's completely?
That's quite a story. You had me a 'stack of washers.' I believe I have access to all the factory TSB's, so if you know when that one was published, let me know and I'll look for it....
So are you done with 944's completely?
That's quite a story. You had me a 'stack of washers.' I believe I have access to all the factory TSB's, so if you know when that one was published, let me know and I'll look for it....
Heads off
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Those parts look amazing! Looks like I need to buy another tool for the garage. What media did you use?
Bill
1986 944 Turbo, my hobby
2008 997 Cabriolet, our fun car
2022 Tesla Model 3, daily driver
Las Vegas, NV
1986 944 Turbo, my hobby
2008 997 Cabriolet, our fun car
2022 Tesla Model 3, daily driver
Las Vegas, NV
We have a huge industrial blaster at work which has glass in it right now.Bill wrote: Wed May 10, 2023 8:35 am Those parts look amazing! Looks like I need to buy another tool for the garage. What media did you use?
Just as a heads up for everyone to never use glass on internal parts.
Anything I have blasted has been 100% sealed of from any glass contamination.
I am lucky to a plethora of items and or hardware to block of fittings and various openings. One such example my crazy aluminum block off plates you see on the cylinder head.
Vapor blasters are much cleaner and less abrasive.
Chris White mentioned he uses soda which is ideal for regular blasting and I would also recommend for a home cabinet.
Last edited by gruhsy on Wed May 10, 2023 10:23 am, edited 1 time in total.
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chris white
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never glass bead a cylinder head....I did a 'bench head' that I use for mock ups and 2 years later it still spits up a glass bead every now and then! Soda blasting is best for any parts that are internally exposed to oil/intake air/coolant.