HIGHWAYMAN: Bringing the Devore 928 back from the dead
03-17-2017, 04:17 PM
#616
The Parts Whisperer
Rennlist
Site Sponsor
Rennlist
Site Sponsor
Not sure if this is of any help to anyone but:
Here is the info on the heads that Kelly Moss did
lift intake port velocity exhaust port velocity
100 102.8 76.4 94.8 131
200 204.3 151.8 173.9 207
300 288.2 214.1 236.2 281
400 330.5 245.6 247 294
500 350.4 260.3 250 298
600 354.2 263.2 252.4 301
stock head was 274 cfm at .500
all measurements done at 28"
Here is the info on the heads that Kelly Moss did
lift intake port velocity exhaust port velocity
100 102.8 76.4 94.8 131
200 204.3 151.8 173.9 207
300 288.2 214.1 236.2 281
400 330.5 245.6 247 294
500 350.4 260.3 250 298
600 354.2 263.2 252.4 301
stock head was 274 cfm at .500
all measurements done at 28"
03-17-2017, 04:28 PM
#617
Banned
Thread Starter
Porsche had the main heavy duty cable from the +ve battery terminal to feed the high current to starter and alternator. The two separate (smaller) cables to feed the engine electronics.
This helps to not have starter motor impulses interfere with the engine electronics...
This helps to not have starter motor impulses interfere with the engine electronics...
Not really a factor with a standalone ECU. Much better shielding that crappy Kjet / CIS / DME, but point taken.
03-17-2017, 05:14 PM
#618
Developer
Adam,
Your heads went on and got torqued today. Now your engine is in our engine oven for its first of 3 heat cycles because of the MLS head gaskets. That will be completed by Monday, and then we will do the final re-torque of the heads. Cams and cam drive will come come next.
Your heads went on and got torqued today. Now your engine is in our engine oven for its first of 3 heat cycles because of the MLS head gaskets. That will be completed by Monday, and then we will do the final re-torque of the heads. Cams and cam drive will come come next.
03-18-2017, 02:32 PM
#621
Developer
If it first it seems a little questionable to heat-cycle your engine in an oven, let me tell you we did too when we first thought about it.
But the science seemed good (the aluminum block will expand in size with heat and crush the **** out of the head gaskets - much more than head stud or bolt torque alone - and then when the block cools and shrinks, the heads stud nuts will no longer be at torque spec).
So we built our first oven in 2006 and waited to see the results before we said a word to anyone. Yep! After heat-cycling the head studs nuts were all soft on torque more than just waiting and re-torquing them after an hour or whatever. It was real. The science was good.
It is not necessary to re torque your heads with stock head gaskets or our Graphite Composite Steel (GCS) head gaskets.
This is only needed when using Multi-Layer Steel (MLS) head gaskets, the manufacturer (Cometic) requires the heads be re-torqued after the first heat cycle. And if you remember, Porsche also requires the re-torquing of the heads after 30 minutes for the 16v 928 engine. Probably not a bad idea for the 32v motor either.
Problem is the huge PITA of removing your cams and losing your timing setup just so that you can re-torque your heads. 32V motors especially, but its a bit of a PITA with 16v too, especially with the motors in the car.
The engine oven allows us to heat-cycle the motor, re-torque the heads, and then install the cams and time the motor. The assembled engine is too large to be put in to our powder-coating paint oven so we instead build an oven around the engine. We use two quartz lamps that emit 18,846 BTU's.
I liked infra-red for application because our goal is to heat the metal, not the air around the metal. In turn, the metal does heat the air in the oven very well also, so we are sure to get a uniform heat throughout the motor. We bring the motor to 240 deg F and hold it there for several hours to confirm that even the innermost parts of the block have gotten to temp. When not in use, the engine oven breaks down flat and we can store it easily until we need it next.
This process, and the engine dyno that will follow, is in keeping with our goal to provide Adam a ready-to-race motor right out of our shipping crate. When he receives it it will already have been run-in, piston rings bedded, and tuned. We are sending the CPU with the motor so he has only to wire it in.
But the science seemed good (the aluminum block will expand in size with heat and crush the **** out of the head gaskets - much more than head stud or bolt torque alone - and then when the block cools and shrinks, the heads stud nuts will no longer be at torque spec).
So we built our first oven in 2006 and waited to see the results before we said a word to anyone. Yep! After heat-cycling the head studs nuts were all soft on torque more than just waiting and re-torquing them after an hour or whatever. It was real. The science was good.
It is not necessary to re torque your heads with stock head gaskets or our Graphite Composite Steel (GCS) head gaskets.
This is only needed when using Multi-Layer Steel (MLS) head gaskets, the manufacturer (Cometic) requires the heads be re-torqued after the first heat cycle. And if you remember, Porsche also requires the re-torquing of the heads after 30 minutes for the 16v 928 engine. Probably not a bad idea for the 32v motor either.
Problem is the huge PITA of removing your cams and losing your timing setup just so that you can re-torque your heads. 32V motors especially, but its a bit of a PITA with 16v too, especially with the motors in the car.
The engine oven allows us to heat-cycle the motor, re-torque the heads, and then install the cams and time the motor. The assembled engine is too large to be put in to our powder-coating paint oven so we instead build an oven around the engine. We use two quartz lamps that emit 18,846 BTU's.
I liked infra-red for application because our goal is to heat the metal, not the air around the metal. In turn, the metal does heat the air in the oven very well also, so we are sure to get a uniform heat throughout the motor. We bring the motor to 240 deg F and hold it there for several hours to confirm that even the innermost parts of the block have gotten to temp. When not in use, the engine oven breaks down flat and we can store it easily until we need it next.
This process, and the engine dyno that will follow, is in keeping with our goal to provide Adam a ready-to-race motor right out of our shipping crate. When he receives it it will already have been run-in, piston rings bedded, and tuned. We are sending the CPU with the motor so he has only to wire it in.
Last edited by Carl Fausett; 03-18-2017 at 06:02 PM.
03-18-2017, 03:47 PM
#622
Electron Wrangler
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Agreed the Blue Sea Systems gear is very nice stuff indeed. Generally you are right all marine products are very well constructed and better than generic automotive stuff. Going bigger gauge does help - Porsche did under-specify some of the stock primary wiring. The stock battery cable to the starter is 35mm^2 while your 2/0 cable is almost twice that cross section area.
On the stock car it was the supplemental feeders for cooling fans, alternator and CE panel feed that were more undersized than the main battery - starter feeder. But if you will run everything through the main supply feed - lower voltage drops & noise is still important. Just keep the other feeders similarly upsized like you have done so far.
I wouldn't have painted over that ground connection - better to use a purpose designed protective spray (keeps out air & moisture - but you can still see the connection quality and wipe it off easily if the connections later need to come apart.
I'm also not a very big fan of the split loom. It is easy for sure and certainly is better than nothing - but I think full sleeving (or heat rated as needed) is better for general protection. I like fiberglass expandable sleeving for general wear and abrasion protection as needed, also easy to use and looks very good when finished. Short sections of heavy duty heat shrink are good for finishing & air sealing the ends @ terminals and also for extra abrasion protection at grommets or known flex/rub points etc.
WaytekWire.com has all these (and more) including Blue seas systems products.
Alan
On the stock car it was the supplemental feeders for cooling fans, alternator and CE panel feed that were more undersized than the main battery - starter feeder. But if you will run everything through the main supply feed - lower voltage drops & noise is still important. Just keep the other feeders similarly upsized like you have done so far.
I wouldn't have painted over that ground connection - better to use a purpose designed protective spray (keeps out air & moisture - but you can still see the connection quality and wipe it off easily if the connections later need to come apart.
I'm also not a very big fan of the split loom. It is easy for sure and certainly is better than nothing - but I think full sleeving (or heat rated as needed) is better for general protection. I like fiberglass expandable sleeving for general wear and abrasion protection as needed, also easy to use and looks very good when finished. Short sections of heavy duty heat shrink are good for finishing & air sealing the ends @ terminals and also for extra abrasion protection at grommets or known flex/rub points etc.
WaytekWire.com has all these (and more) including Blue seas systems products.
Alan
One of the few things automotive related that I have formal training in is with 12 volt systems. As a wayward kid, Dad sent me off to the local technical school where I was more or less forced to obtain a 2 year certificate in electronics engineering. It sounds fancy, but it is not a degree nor am I an engineer. It was basically a two year course on the design of 12 volt systems, batteries, soldering, wiring, and a bunch of other crap. I hated it at the time, but 25 years later I can't believe how lost I would be without a solid foundation in DC systems design.
So I normally don't sweat electrical issues in cars, and I have built more than one wiring harness from scratch. The Devore car has ZERO existing wiring, which is great because lots of race cars still have the heavy stock harness in place. In this case, Devore = blank slate, which I like the best.
Some months ago I put in an optima gel battery and box in the right rear passenger seat, left unwired for the time being.
Today was the day to begin the foundation of any DC system - the battery connections. I always do the battery first, and then branch from there.
In another career after school, I spent 10 years in the marine industry and thus the way I do things in the cars is very marine-like. For example, I am a fan of Blue Sea systems products and Ancor wiring connectors. Both are exclusively boat products, but they are WAY tougher than equivalent automotive stuff.
I don't much care how much weight the DC system adds to the car. I always go with a full sized battery and a minimum of 2/0 cables for power. Sure, it adds weight, but who wants to chase ground and power issues because you're trying to save weight.
In this case, I began by routing the old battery cable to the new location by drilling a hole in the bulkhead and putting in a grommet.
I used a Blue Sea battery disconnect for maintenance purposes. It should be noted that this off switch is NOT the emergency disconnect used by first responders. The Devore car already has such a system, with two separate disconnects, one external and one close to the driver. The switch I installed today would be upstream of that, and it's basically a maintenance and storage disconnect.
The Blue Sea stuff is overbuilt and this switch has a 1500 amp cranking rating, which is an order of magnitude more than will be needed.
Next it was time to tackle the ground. People get wrapped around the axle on grounds. In this situation, the ground can be anywhere you want it to be, so long as it's good and solid. I sanded away a convenient location, then welded a bolt directly onto the chassis for a firm, solid ground that I could bolt a battery lug to. It doesn't get much better than this for good grounds.
Finally - and this is super important - once I bolted by negative battery cable down, I immediately painted over the whole assembly with the same undercoater the interior is done in.
Corroded grounds are a MAJOR issue in a multitude of electrical problems that plague many cars. It's important to immediately protect the area from corrosion, so the paint covers everything, while the metal to metal connection is still preserved underneath.
Some of my practices are:
- always use split loom one wiring to prevent chafe
- all heavy gauge wires get hold downs as necessary
- Always use marine grade crimp on lugs with a marine crimper on battery cables.
- Cover the cable almost to the end with electrical tape to prevent corrosion
So now we have the foundation of the battery system. Now onto the accessories!
The undercoater paint in the picture hasn't laid down yet and looks lumpy.
So I normally don't sweat electrical issues in cars, and I have built more than one wiring harness from scratch. The Devore car has ZERO existing wiring, which is great because lots of race cars still have the heavy stock harness in place. In this case, Devore = blank slate, which I like the best.
Some months ago I put in an optima gel battery and box in the right rear passenger seat, left unwired for the time being.
Today was the day to begin the foundation of any DC system - the battery connections. I always do the battery first, and then branch from there.
In another career after school, I spent 10 years in the marine industry and thus the way I do things in the cars is very marine-like. For example, I am a fan of Blue Sea systems products and Ancor wiring connectors. Both are exclusively boat products, but they are WAY tougher than equivalent automotive stuff.
I don't much care how much weight the DC system adds to the car. I always go with a full sized battery and a minimum of 2/0 cables for power. Sure, it adds weight, but who wants to chase ground and power issues because you're trying to save weight.
In this case, I began by routing the old battery cable to the new location by drilling a hole in the bulkhead and putting in a grommet.
I used a Blue Sea battery disconnect for maintenance purposes. It should be noted that this off switch is NOT the emergency disconnect used by first responders. The Devore car already has such a system, with two separate disconnects, one external and one close to the driver. The switch I installed today would be upstream of that, and it's basically a maintenance and storage disconnect.
The Blue Sea stuff is overbuilt and this switch has a 1500 amp cranking rating, which is an order of magnitude more than will be needed.
Next it was time to tackle the ground. People get wrapped around the axle on grounds. In this situation, the ground can be anywhere you want it to be, so long as it's good and solid. I sanded away a convenient location, then welded a bolt directly onto the chassis for a firm, solid ground that I could bolt a battery lug to. It doesn't get much better than this for good grounds.
Finally - and this is super important - once I bolted by negative battery cable down, I immediately painted over the whole assembly with the same undercoater the interior is done in.
Corroded grounds are a MAJOR issue in a multitude of electrical problems that plague many cars. It's important to immediately protect the area from corrosion, so the paint covers everything, while the metal to metal connection is still preserved underneath.
Some of my practices are:
- always use split loom one wiring to prevent chafe
- all heavy gauge wires get hold downs as necessary
- Always use marine grade crimp on lugs with a marine crimper on battery cables.
- Cover the cable almost to the end with electrical tape to prevent corrosion
So now we have the foundation of the battery system. Now onto the accessories!
The undercoater paint in the picture hasn't laid down yet and looks lumpy.
03-18-2017, 11:56 PM
#623
Banned
Thread Starter
Agreed the Blue Sea Systems gear is very nice stuff indeed. Generally you are right all marine products are very well constructed and better than generic automotive stuff. Going bigger gauge does help - Porsche did under-specify some of the stock primary wiring. The stock battery cable to the starter is 35mm^2 while your 2/0 cable is almost twice that cross section area.
On the stock car it was the supplemental feeders for cooling fans, alternator and CE panel feed that were more undersized than the main battery - starter feeder. But if you will run everything through the main supply feed - lower voltage drops & noise is still important. Just keep the other feeders similarly upsized like you have done so far.
I wouldn't have painted over that ground connection - better to use a purpose designed protective spray (keeps out air & moisture - but you can still see the connection quality and wipe it off easily if the connections later need to come apart.
I'm also not a very big fan of the split loom. It is easy for sure and certainly is better than nothing - but I think full sleeving (or heat rated as needed) is better for general protection. I like fiberglass expandable sleeving for general wear and abrasion protection as needed, also easy to use and looks very good when finished. Short sections of heavy duty heat shrink are good for finishing & air sealing the ends @ terminals and also for extra abrasion protection at grommets or known flex/rub points etc.
WaytekWire.com has all these (and more) including Blue seas systems products.
Alan
On the stock car it was the supplemental feeders for cooling fans, alternator and CE panel feed that were more undersized than the main battery - starter feeder. But if you will run everything through the main supply feed - lower voltage drops & noise is still important. Just keep the other feeders similarly upsized like you have done so far.
I wouldn't have painted over that ground connection - better to use a purpose designed protective spray (keeps out air & moisture - but you can still see the connection quality and wipe it off easily if the connections later need to come apart.
I'm also not a very big fan of the split loom. It is easy for sure and certainly is better than nothing - but I think full sleeving (or heat rated as needed) is better for general protection. I like fiberglass expandable sleeving for general wear and abrasion protection as needed, also easy to use and looks very good when finished. Short sections of heavy duty heat shrink are good for finishing & air sealing the ends @ terminals and also for extra abrasion protection at grommets or known flex/rub points etc.
WaytekWire.com has all these (and more) including Blue seas systems products.
Alan
I can tell I am speaking to a similar electronics geek! Nice to meet you!
What spray would you recommend?
Agreed on everything else including split loom with one proviso - If I was 100% certain of the configuration of the system I would use the heat resistant sleeving, which I typically use for engine bay wiring. However, I thought since I might have to change something or modify it to suit future wiring, I would stick with split loom for easy access. Once I am certain the the configuration won't change, I will probably go back and make a more permanent solution.
Thanks for your input!
03-19-2017, 04:15 PM
#624
Electron Wrangler
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Something like this - there are many versions - go with a good brand for quality.
Alan
Alan
03-24-2017, 05:50 PM
#625
Developer
Some have asked about what to do with the cast-in throttle supports when you build up a 85/86 block. Depending on what intake you use, they can get in the way.
These two pics show how we remove them, and a view underneath Adam's custom intake shoe to show how much room there is.
These two pics show how we remove them, and a view underneath Adam's custom intake shoe to show how much room there is.
03-24-2017, 05:54 PM
#626
Developer
Ready to go to the Engine Dyno
The engine is sitting pretty and ready to go to the engine dyno. The first intake manifold we will be testing is on it, and the second one sits nearby. The dyno headers sit on the floor.
I have sceduled the dyno for Monday and Tuesday.
I have sceduled the dyno for Monday and Tuesday.
03-24-2017, 06:57 PM
#627
Banned
Thread Starter
Can't wait, Carl. That color combo looks damn good to my eye, even if it is different. And being different is what I do best. Finally, the Devore car gets a heart after sitting dead for decades!
03-25-2017, 11:46 AM
#629
Developer
Yes. At times, I will be a couple yards away and on the other side of the glass when dynoing the motor. I like a nice big analog oil pressure gauge for this - I can see it from a distance, plus most dyno's aren't wired to expect a Porsche coolant temp sensor, so I don't have to mess around re calibrating their gauge to my sender or installing their sender into the Porsche (which invariably will be the wrong thread).
03-29-2017, 05:01 PM
#630
Developer
First days at the dyno
We had a good first couple days at the dyno, and here are a few pics taken as we set up the engine and hooked it all up.
The engine ran-in well, but we found that the big intake shoe that we had welded up had warped, and it caused a vacuum leak at idle. We have machined that mounting flange flat again and are going back at it.
We will be back at the dyno with this motor next week to finish up the tune.
I will have two intake manifolds with me; an all-stock 1988-style intake manifold, shoe, and 75mm throttle body, and our extrude-honed intake with large shoe and 90mm throttle body. The design and build of this intake system is discussed in this thread back a few pages, starting about at post 352.
The engine ran-in well, but we found that the big intake shoe that we had welded up had warped, and it caused a vacuum leak at idle. We have machined that mounting flange flat again and are going back at it.
We will be back at the dyno with this motor next week to finish up the tune.
I will have two intake manifolds with me; an all-stock 1988-style intake manifold, shoe, and 75mm throttle body, and our extrude-honed intake with large shoe and 90mm throttle body. The design and build of this intake system is discussed in this thread back a few pages, starting about at post 352.