blown engine
02-02-2017, 05:29 PM
#871
One clarification on the video is the engine could have started in 3s if I had let it. I followed Jake's procedure of cycling the ignition key. Basically crank the engine but turn it off just when it fires up. Do that a few times to build up oil pressure before letting it idle normally. You can see the oil pressure needle jumps higher and higher after every key on/off cycle.
02-02-2017, 07:02 PM
#874
02-03-2017, 12:39 PM
#878
Racer
Thread Starter
.
congrats on a great build - we're lucky to have this process so well documented!
02-03-2017, 03:23 PM
#880
Indeed you were very easy on the clutch. The flywheel, pressure plate, throw out bearings are all in great condition. I didn't know a new LUK FW costs ~$400 shipped to my door and foolishly spent $150 on resurfacing and rebalancing the stock flywheel.
Actually the blown engine was in very good shape (other than the IMS/IMSB and the natural cylinder ovaling). Both tailpipes were so clean with no dark soot. Fuel trim numbers were great.
Thanks!
02-03-2017, 04:52 PM
#881
Drifting
1. Ahsai is a Raby-school graduate so he is doing everything correctly- unlike other builders like me !.
2. He documented all the major stages and posted lots of photos
3. He confessed his mistakes
4. Named and shared the costs,equipment/tools/parts/sources used
And he took all the time to explain all this to us. That is a great gift to the M96 community/asylum
That said , any one who has done an M96 rebuild knows there is a lot that could not be included . There is way more to it than only what is described.
For example ,he was able to skip the whole bore/piston evaluation stage - worthy of many pages on it's own !
I hope this becomes not just a Sticky but a Section on M96 rebuilding - like Pelican has for the 993/964 & others for example. It would draw a lot of traffic and Sponsors to this Forum .
As these engines age & wear out, there will be increasing need for this work to be done diy so I hope Ahsai's work is augmented by others in future.
Thank you Duncan.
02-03-2017, 07:47 PM
#882
Racer
Thread Starter
You bet! Would like you to be the 1st person to test drive it after me.
Indeed you were very easy on the clutch. The flywheel, pressure plate, throw out bearings are all in great condition. I didn't know a new LUK FW costs ~$400 shipped to my door and foolishly spent $150 on resurfacing and rebalancing the stock flywheel.
Actually the blown engine was in very good shape (other than the IMS/IMSB and the natural cylinder ovaling). Both tailpipes were so clean with no dark soot. Fuel trim numbers were great.
Thanks!
Indeed you were very easy on the clutch. The flywheel, pressure plate, throw out bearings are all in great condition. I didn't know a new LUK FW costs ~$400 shipped to my door and foolishly spent $150 on resurfacing and rebalancing the stock flywheel.
Actually the blown engine was in very good shape (other than the IMS/IMSB and the natural cylinder ovaling). Both tailpipes were so clean with no dark soot. Fuel trim numbers were great.
Thanks!
What makes me internally proud is that I sold my 996.2 to someone who gave it (and is giving) it pure love and attention.
02-06-2017, 04:00 PM
#883
There are others who posted parts of their partial builds. But there are several distinctions to Ahsai's work:
1. Ahsai is a Raby-school graduate so he is doing everything correctly- unlike other builders like me !.
2. He documented all the major stages and posted lots of photos
3. He confessed his mistakes
4. Named and shared the costs,equipment/tools/parts/sources used
And he took all the time to explain all this to us. That is a great gift to the M96 community/asylum
That said , any one who has done an M96 rebuild knows there is a lot that could not be included . There is way more to it than only what is described.
For example ,he was able to skip the whole bore/piston evaluation stage - worthy of many pages on it's own !
I hope this becomes not just a Sticky but a Section on M96 rebuilding - like Pelican has for the 993/964 & others for example. It would draw a lot of traffic and Sponsors to this Forum .
As these engines age & wear out, there will be increasing need for this work to be done diy so I hope Ahsai's work is augmented by others in future.
Thank you Duncan.
1. Ahsai is a Raby-school graduate so he is doing everything correctly- unlike other builders like me !.
2. He documented all the major stages and posted lots of photos
3. He confessed his mistakes
4. Named and shared the costs,equipment/tools/parts/sources used
And he took all the time to explain all this to us. That is a great gift to the M96 community/asylum
That said , any one who has done an M96 rebuild knows there is a lot that could not be included . There is way more to it than only what is described.
For example ,he was able to skip the whole bore/piston evaluation stage - worthy of many pages on it's own !
I hope this becomes not just a Sticky but a Section on M96 rebuilding - like Pelican has for the 993/964 & others for example. It would draw a lot of traffic and Sponsors to this Forum .
As these engines age & wear out, there will be increasing need for this work to be done diy so I hope Ahsai's work is augmented by others in future.
Thank you Duncan.
I'll definitely take you up on the test drive offer. I am totally blown away to your attention to detail and documentation. I suspect that this thread will be looked at by anyone who wants to rebuild the M96 engine.
What makes me internally proud is that I sold my 996.2 to someone who gave it (and is giving) it pure love and attention.
What makes me internally proud is that I sold my 996.2 to someone who gave it (and is giving) it pure love and attention.
02-06-2017, 04:20 PM
#884
Instructor
Join Date: Jul 2016
Location: Florida
Posts: 239
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Random comment but I'm at work and have been staring at JIRA all day- had an odd realization that forums are the equivalent to a Confluence project space... Great work Ahsai, you're a legend!
02-06-2017, 04:32 PM
#885
First driving impression
Ok, here's the update some of you have been waiting for!
Car passed smog and the 3.8 indeed pulls strong! Very similar to my '03 3.6 below 3k but above 3k, it's pulling very strongly all the way to 6k (I have not touched the redline yet). Put 90 miles on it so far and it's fantastic. The idle is silky smooth. Smoother than my '03 for sure. I guess my meticulous part swapping piston/rod/pin/rings balancing paid off!
The engine cranks with very even compression and it fires right up with gusto cold or warm. I can barely feel it idling. All the fuel trims are practically 0.
FRA is 1.02 on bank 1 (i.e., 2% of fuel is added under heavy load)
FRA is 0.99 on bank 2 (i.e., 1% of fuel is pulled under heavy load)
RKAT is 0.66% on bank 1 (i.e., 0.66% of fuel is added at idle)
RKAT is 1.41% on bank 2 (i.e., 1.41% of fuel is added at idle)
Cam deviations are 3.48 on bank 1 and 2.58 on bank 2. I'm not worrying as I can always adjust them later if needed. Rough cylinder measurements at idle hovers around 0.0 most of the time and it goes to at most 0.7 for all cylinders! Again, very very smooth.
MAF is ~5.2g/s at idle as compared to ~5g/s for my 3.6. It make sense because 3.8 is about 5.5% increase in displacement so it sucks in about that much more of air (I know it's not linear but it's darn close). The fuel trims above also have answered a question I have had for a long time. Are they w.r.t the measured air mass or an absolute air mass expected at a specific rpm? The answer is the former. It makes a lot of sense because each engine has some variations so some breath better than the others and the DME will have to be able to compensate and handle them. With only 5.5% increase, the DME has no problems handling the extra 200cc. It just adds more fuel (compared to 3.6) to reach the stoichiometric ratio. The fact that the fuel trims are close to 0 means everything is good.
Coolant temp and oil pressure are also great and normal. Alternator voltage output looks great too (I installed a brand new y-cable).
Now the chassis itself needs some attention. The tires are all-season. The front tires are 8yrs old! Gonna put a set of Continental DW on. The left radiator shroud so that will be replaced soon. The transmission is great. The suspension feels tired but coming out from my x74, everything else will feel very sloppy.
Overall, the car is in excellent shape.
Next stop is 300 miles. Oil change and the oil pan will be dropped for inspection, along with other inspections.
Car passed smog and the 3.8 indeed pulls strong! Very similar to my '03 3.6 below 3k but above 3k, it's pulling very strongly all the way to 6k (I have not touched the redline yet). Put 90 miles on it so far and it's fantastic. The idle is silky smooth. Smoother than my '03 for sure. I guess my meticulous part swapping piston/rod/pin/rings balancing paid off!
The engine cranks with very even compression and it fires right up with gusto cold or warm. I can barely feel it idling. All the fuel trims are practically 0.
FRA is 1.02 on bank 1 (i.e., 2% of fuel is added under heavy load)
FRA is 0.99 on bank 2 (i.e., 1% of fuel is pulled under heavy load)
RKAT is 0.66% on bank 1 (i.e., 0.66% of fuel is added at idle)
RKAT is 1.41% on bank 2 (i.e., 1.41% of fuel is added at idle)
Cam deviations are 3.48 on bank 1 and 2.58 on bank 2. I'm not worrying as I can always adjust them later if needed. Rough cylinder measurements at idle hovers around 0.0 most of the time and it goes to at most 0.7 for all cylinders! Again, very very smooth.
MAF is ~5.2g/s at idle as compared to ~5g/s for my 3.6. It make sense because 3.8 is about 5.5% increase in displacement so it sucks in about that much more of air (I know it's not linear but it's darn close). The fuel trims above also have answered a question I have had for a long time. Are they w.r.t the measured air mass or an absolute air mass expected at a specific rpm? The answer is the former. It makes a lot of sense because each engine has some variations so some breath better than the others and the DME will have to be able to compensate and handle them. With only 5.5% increase, the DME has no problems handling the extra 200cc. It just adds more fuel (compared to 3.6) to reach the stoichiometric ratio. The fact that the fuel trims are close to 0 means everything is good.
Coolant temp and oil pressure are also great and normal. Alternator voltage output looks great too (I installed a brand new y-cable).
Now the chassis itself needs some attention. The tires are all-season. The front tires are 8yrs old! Gonna put a set of Continental DW on. The left radiator shroud so that will be replaced soon. The transmission is great. The suspension feels tired but coming out from my x74, everything else will feel very sloppy.
Overall, the car is in excellent shape.
Next stop is 300 miles. Oil change and the oil pan will be dropped for inspection, along with other inspections.