Twin Turbo 928 fixed and back out there terrorizing the streets!
#2267
Nordschleife Master
Thread Starter
#2268
Rennlist Member
Join Date: Feb 2011
Location: Mostly in my workshop located in Sweden.
Posts: 2,230
Received 463 Likes
on
248 Posts
The PAC-1223X is a bit stiffer.
Åke
Åke
- Part#PAC-1223
- NamePAC-1223 Ford 4.6L 4V 0.500 Lift Ovate Wire Beehive
- SKUPAC-1223
- Alt Part#PAC-1223-16
- DescriptionFord 4.6L 4V .500 lift Ovate Beehive Valve Spring
- OD Large End1.105
- ID Large End0.742
- ID Small End0.580
- Install Height1.470
- Load at Installed Height90
- Spring Open Height0.970
- Spring Open Load252
- Recommended Valve Lift0.500
- Spring Rate (lbs/in)324.000
- Mass (grams)37.60
- Coil Bind (max)0.900
- Part#PAC-1223X
- NamePAC-1223X RPM Series Ford 4.6L 4V 0.500 Lift Ovate Wire Beehive
- SKUPAC-1223X
- Alt Part#PAC-1223X-16
- DescriptionBeehive RPM Series Valve Spring Ford 4.6L 4 Valve
- OD Large End1.105
- ID Large End0.742
- ID Small End0.943
- Install Height1.470
- Load at Installed Height100
- Spring Open Height0.970
- Spring Open Load262
- Recommended Valve Lift0.500
- Spring Rate (lbs/in)324
- Mass (grams)46
- Coil Bind (max)0.900
#2269
Nordschleife Master
Thread Starter
Millenium
Looks like Millenium Technologies liked John’s crate. I’m not on Facebook (I’m old, but not that old!), but the web page version has photos:
#2270
Nordschleife Master
Thread Starter
Main bearings and modified cams
Main bearing grooving fixtures made. Also, the cams were corrected to run on S4 heads, took a long while of machine time to do it safely as it’s hard material. Those passes were only 0.001" per pass.
#2271
Nordschleife Master
Thread Starter
John’s fixture to turn any block into a squirter block
Our math says that to run a high rpm 928 engine with good cylinder seal and oil control, we need thin piston rings. To run thin piston rings while making adequate torque, our math says the engine needs piston oil squirters to cool the pistons. Instead of hunting for rare squirter blocks, John had fixtures made that allow him to covert any 928 S4/later block to a squirter block:
#2272
Rennlist Member
I'm guessing cams are case hardened, so at some point you run out of hardness. How much was removed w.r.t. depth of hardness? Also, out of curiosity, why machine vs. grind? Thx!
#2273
Nordschleife Master
Thread Starter
It’s chill cast and I don’t think there’s any further case hardening or heat treatment, although I could be wrong. I don’t think this journal needs the same level of hardness as the lobes, anyway.
Here’s the machine that was used, don’t know enough why it was done the way it was:
#2275
Nordschleife Master
Thread Starter
#2276
Nordschleife Master
Thread Starter
This would be the worst time to be bitten by a tick
...because then you’d have Corona with Lyme.
Thank you thank you, I’ll be here all month (other than I’ll have to go buy the stock market at the end of the March when the global infection rates are expected to stabilize)!
In the real world, here are some of John Kuhn’s new tools. A drill bit and a reamer to create piston oil squirter housing bores into the 928 block:
Thank you thank you, I’ll be here all month (other than I’ll have to go buy the stock market at the end of the March when the global infection rates are expected to stabilize)!
In the real world, here are some of John Kuhn’s new tools. A drill bit and a reamer to create piston oil squirter housing bores into the 928 block:
#2278
Rennlist Member
Join Date: Feb 2011
Location: Mostly in my workshop located in Sweden.
Posts: 2,230
Received 463 Likes
on
248 Posts
What’s the logic? Something to do with “oil timing”? The area alone should be sufficient without the extra holes. As an additional factor, the Simard engine has a striker crank with single straight oil passage without cross drilling, while these engines will have stock crankshaft with cross drilled center mains.
https://www.substech.com/dokuwiki/do...mance_bearings
The picture showing a main bearing shell with additional oil feed holes is from Mike Simard. I suppose that is how he modified the main bearing shells in the 7 liter stroker engine.
I came up with the same idea sometimes in the early or mid seventies when I noticed BMW went from only one hole to two or more slotsin the bearing shells. Here is the theory behind it https://www.substech.com/dokuwiki/do...mance_bearings
In those days I did not have a milling machine to do the slots so the drilling of additional oil holes was the obvious thing to do.
I once had severe problems of failed Glyco rod bearings on highly modified BMW motorcycle engines. The drilling of additional oil holes in the mains and the installation of harder Clevite rod bearings solved the problem.
For the 928 engine block in order to increase the oil flow I will port the oil gallery all the way from the pick up in the sump to engine bearings. I will port the oil gallery going around the main bearings in the block and the girdle. It can be done using a die grinder and a suitable sized rotating file.
Åke
#2279
Nordschleife Master
Thread Starter
First I like your oil groove but it need deburring.
https://www.substech.com/dokuwiki/do...mance_bearings
The picture showing a main bearing shell with additional oil feed holes is from Mike Simard. I suppose that is how he modified the main bearing shells in the 7 liter stroker engine.
I came up with the same idea sometimes in the early or mid seventies when I noticed BMW went from only one hole to two or more slotsin the bearing shells. Here is the theory behind it https://www.substech.com/dokuwiki/do...mance_bearings
In those days I did not have a milling machine to do the slots so the drilling of additional oil holes was the obvious thing to do.
I once had severe problems of failed Glyco rod bearings on highly modified BMW motorcycle engines. The drilling of additional oil holes in the mains and the installation of harder Clevite rod bearings solved the problem.
For the 928 engine block in order to increase the oil flow I will port the oil gallery all the way from the pick up in the sump to engine bearings. I will port the oil gallery going around the main bearings in the block and the girdle. It can be done using a die grinder and a suitable sized rotating file.
Åke
https://www.substech.com/dokuwiki/do...mance_bearings
The picture showing a main bearing shell with additional oil feed holes is from Mike Simard. I suppose that is how he modified the main bearing shells in the 7 liter stroker engine.
I came up with the same idea sometimes in the early or mid seventies when I noticed BMW went from only one hole to two or more slotsin the bearing shells. Here is the theory behind it https://www.substech.com/dokuwiki/do...mance_bearings
In those days I did not have a milling machine to do the slots so the drilling of additional oil holes was the obvious thing to do.
I once had severe problems of failed Glyco rod bearings on highly modified BMW motorcycle engines. The drilling of additional oil holes in the mains and the installation of harder Clevite rod bearings solved the problem.
For the 928 engine block in order to increase the oil flow I will port the oil gallery all the way from the pick up in the sump to engine bearings. I will port the oil gallery going around the main bearings in the block and the girdle. It can be done using a die grinder and a suitable sized rotating file.
Åke
we studied the flow paths and are trying a narrower groove with holes drilled into the groove. There’s a theoretical gain there because the bearing area is larger that way
#2280
Rennlist Member
Join Date: Feb 2011
Location: Mostly in my workshop located in Sweden.
Posts: 2,230
Received 463 Likes
on
248 Posts
Yes, the groove looked a bit wide but on the other hand most of the load will be on the lower bearing shell which is not grooved.
I believe it is important to get as good as possible of oil flow up the the mains. With more power and higher rpm the side leakage will increase.
In order to increase the oil supply to the con rod bearings I usually tear drop the oil drillings in the crankshaft. Not long ago I did this kind of modifications on several BMW six cranks I have in the shop (pictures).
Åke
I believe it is important to get as good as possible of oil flow up the the mains. With more power and higher rpm the side leakage will increase.
In order to increase the oil supply to the con rod bearings I usually tear drop the oil drillings in the crankshaft. Not long ago I did this kind of modifications on several BMW six cranks I have in the shop (pictures).
Åke