In reply to yupididit :
Probably Advertized horsepower. In other words based on Group 44's averaged dyno numbers. ( which would be gross).
In reply to yupididit :
Probably Advertized horsepower. In other words based on Group 44's averaged dyno numbers. ( which would be gross).
mke said:In reply to Paul_VR6 (Forum Supporter) :
Mine were crank numbers ....so WELL below your numbers
....a 308 is about 18 drop crank to wheel
Half the stuff we can't dyno due to traction anyway 
frenchyd said:Paul_VR6 (Forum Supporter) said:Seems like you are more efficicent as all my numbers are with IC, but my numbers are also whp so could be close-ish. We are at those power levels at 20psi pump and 30psi e85, but turbo choice, etc can push them a lot higher (have some race cars at 900+ on stock bottoms with just arp bolts and studs, springs and cams
but with turbos that are almost unuseable most of the time)
That's part of the reason I selected the turbo I did. I'm not racing a dyno, I not only need to do well in the drag race but also in the autocross. If it was just 1/4 racing. I'd gone bigger.
Calvin Nelson made 824 wheel horsepower on the chassis Dyno using an engine with 175,000 miles on it without any up grades or even opening up the engine except to put a pair of reground camshafts. So depending on what engine it is a lot of that stuff isn't needed.
Calvin Nelson made 824 wheel hp on an engine designed 30 years after the Jaguar V12. If you get everything perfect then on 12 pounds of boost I think you don't make more than 325 wheel hp. There's going to be naturally aspirated engines there making more.
In reply to Stampie :
Maybe you have dates wrong? The last V12 was made in 1997 and the first Atlas was 2002.
maybe if you're talking about the 1971 introduction of the V12? you're closer?
However You might want to look carefully at the Atlas engine. Then spend some time looking at the Jaguar 4. Valve 6 cylinder. Which was based on the V12.
Considering the V12 starts out with 262 net horsepower. Removal of the things designed to make the car quiet, conform to pollution rules, operate on 91 octane gasoline, that gets us over 350 horsepower 12 pounds of boost and E85 might just get me over 325 wheel horsepower.
In reply to frenchyd :
Reading comperhension. Note I said designed. Please stop spreading your myth that GM copied the Jaguar 4 valve 6 cylinder. It's been facted checked before.
frenchyd saiid:mke. That sure was informative. Especially what you said about intake flow above .375 But the reason you went over was to start opening the intake earlier in order to get the flow going. That was a light bulb on moment.
I don't have to chase a pushrod engines .700+ lift. Just get the air going enough to fill the port.
Hopefully you've read what I wrote about heron heads. The advantage they have over a combustion chamber in head.
Putting 2+ 2 together am I going to be better off with a top 1/2 of a ballon shaped cam lobe over a lobe that has straighter sides?
Oops remembering what you said about opening the valve as quickly as possible. I just answered my own question with your help.
So total flow is the sum of time @ duration@presure. The faster the cam opens the valve to higher lifts, the more the sum or total flow will be.
But there are LOTs of buts. Again, here is my engine at 9k rpm, so near peak hp. On the bottom graph you can see the valve open and close points, that is at 0.006" lift at the seat which is when anyti8ng meaningful starts to happen.
Look closely at the At IVO...that is about 40 degrees BTDC so the piston is going up!, but look at the red line that shows the pressure at the exhaust port....its JUST starting to go negative (below 1) and proceeds to drop all the way to about 0.5 or 7 psi VACUUM to start the intake flow. That is what eaders do when they are working correctly.
At about 40 degrees ATDC when the piston is now flying down the bore the the exhasut valve closes and the piston continues to accelerate the intake charge, like the second stage of a rocket kind of.
Now focus on the BDC line. The piston has hit the bottom and is beginning to go back up but notice the presure going up in the intake port, that is the tuned stack forcing air into the cylinder bringing the pressure ration to about 1.3...about the same as 5lbs boost. This yeilds a VE of about 130%, compared to the about .9 it started life at this is really more like 7psi boost.
When you look at this you can see why the valve timing was to be what it is....putting longer duration cams in this engine would LOWER the hp....you can see its already closing just a touch late.
In reply to mke :
I recently watched the effect of long rods versus short rods and the different effect stoke had on piston speed. Then tried to connect that with cam action based on port volume.
It's very much like learning 3 dimensional chess Except it's not. It's actually linear with the only variable being engine speed.
Once the parameters are fixed. Stroke lift duration etc. if I don't want to reduce it all to a numerical solution I can turn the calculation over to the computer and arrive at a solution to satisfy my needs
as I learned earlier Comp cams has a massive library of lobe profiles. Once I have actual flow numbers to work with on my revised ports I should be able to weed through their library, call Crower and see what they think of my selection. And go from there.
Then I need to find a dish head piston with a pin size of .9375 with 1" between the top of the pin and and the top of the piston. A bore size of 3.75
I know JE will make me a set but it's hard to pay those prices when there are so many pistons out there for a tiny fraction of that price. I thought I could use a Buick piston but the cost of opening up the pin size brought the costs too high And I don't have my vertical mill anymore
frenchyd said:In reply to mke :
I recently watched the effect of long rods versus short rods and the different effect stoke had on piston speed.
I learned earlier Comp cams has a massive library of lobe profiles.
I know JE will make me a set
Rods - very little impact...some but not all that important.
I have the CompCams library, its an option with Dynomation. DM also lets you approximate any cam design you like and can be setup iterate making small changes until it finds a optimal design, then you can search the CompCams library for the closest option I didn't find anything I loved but found what I went with at WebCams, I gave them the basics and they send me 5 options for both intake and exhaust and even did a could test grinds, they were very helpful.
JE made my pistons, they do good work
In reply to mke :
Aries made my pistons for the XKE V12 they were a Venolia forging with Aries doing the work. But wow were they heavy 540 grams not counting the pins and rings.
The machine work was brilliant. All 14 pistons I checked were spot on. Not "within tolerance" but exact.
Jaguar has a batch method of manufacturing pistons were divided into Group A & B then lined up in sets with similar tolerance. It's the only way they can be profitable with their low volume.
In reply to frenchyd :
I used Aris, the set they made me were also quite heavy. Wiseco makes nice pistons as well.
That's the thing with low volume or custom engines....they need custom pistons and a lot of other custom stuff. You're talking about a $20+K engine....I've spent about a challenge budget on mine every year for 14 years now to get it mostly running.
In reply to mke :
My Black Jack I built it right and decades later the engine etc is still there in the Packard museum. All it's ever had is normal maintenance.
If you think about it I doubt it has 10,000 competition miles on it. I change the 5 gallons of engine oil every race. Etc.
Hopefully the XJS will get the same treatment.
I have a marketplace notification setup for v12, I kinda want one now
frenchyd said:In reply to mke :
My Black Jack I built it right and decades later the engine etc is still there in the Packard museum. All it's ever had is normal maintenance.
If you think about it I doubt it has 10,000 competition miles on it. I change the 5 gallons of engine oil every race. Etc.
Hopefully the XJS will get the same treatment.
5 gallons of oil?
mke said:
....putting longer duration cams in this engine would LOWER the hp....you can see its already closing just a touch late.
It is pedantry but worth saying, you still show relatively high pressure in the intake port at IVC, assuming that downward knee in the curve is the beginnings of reversion you still have intake charge inertia helping to pack more charge into the cylinder. I don't think it's necessarily past the ideal IVC (for output at that rpm), you're just in the region where you're trading intake charge for compression. No substitue for dyno time on that one.
It's a good looking torque curve, if it does that in real life I wouldn't touch a thing, I would not worry and be happy. Kudos to you for doing real engine development as a private individual, it's a long hard road.
Paul_VR6 (Forum Supporter) said:I have a marketplace notification setup for v12, I kinda want one now
Everybody needs at least 1 V12! ....but choose wisely 
grpb said:It is pedantry but worth saying, you still show relatively high pressure in the intake port at IVC, assuming that downward knee in the curve is the beginnings of reversion you still have intake charge inertia helping to pack more charge into the cylinder. I don't think it's necessarily past the ideal IVC (for output at that rpm), you're just in the region where you're trading intake charge for compression. No substitue for dyno time on that one.
It's a good looking torque curve, if it does that in real life I wouldn't touch a thing, I would not worry and be happy. Kudos to you for doing real engine development as a private individual, it's a long hard road.
Basically...I don't have the software key but I found this in my saved stuff, it looks like I was playing with tuning for max hp so I would have moved the lobe centers (I casn set them where ever I please in the real engine so I spent a lot of time looking at this) along with changing header design and velocity stack length, but this is again at 9k
I'm not sure what I was playing with, but bottom graph, green line is intake velocity at the valve and you can see it go negative just before the valve closes....that is reversion.
Here's another graph that includes a trapped mass line (green line bottom graph). No reversion here but the flow has stopped...so reversion was coming. That pressure comes from velocity of the charge in the port and stack being converted to pressure along with a pressure wave ideally hitting valve as it closes.
I can't find a good graph, but here a table with the info. The columns on the right break down total charge loss and where it went whether reversion or out the exhaust or spoilage (exhaust left in the cylinder)....you can see at idle 20% of the charge it coming back out the intake.
yupididit said:5 gallons of oil?
Dry sump no doubt, my car is 15 quarts.
yupididit said:frenchyd said:In reply to mke :
My Black Jack I built it right and decades later the engine etc is still there in the Packard museum. All it's ever had is normal maintenance.
If you think about it I doubt it has 10,000 competition miles on it. I change the 5 gallons of engine oil every race. Etc.
Hopefully the XJS will get the same treatment.
5 gallons of oil?
Yes. It's more than the factory carried starting back in 1954. I think they were at 3&1/2 gallons. But they would rebuild the engine after only 2 events. Or one 24 hr LeMans.
I wish I could remember how many gallons the engine in the S2 E carried, 54? But those engines were designed to run for 8 hours at a time hundreds of miles from the carrier, then last for several deployments before they were rebuilt.
I'm convinced clean fresh oil goes a long way to keeping an engine alive.
mke said:yupididit said:5 gallons of oil?
Dry sump no doubt, my car is 15 quarts.
That's just a qt short of 4 gallons.
Paul_VR6 (Forum Supporter) said:I have a marketplace notification setup for v12, I kinda want one now
Too bad, I coulda brought you one during the Christmas break. I went through PA to pick up my fender flairs.
Should I be looking around for you? Any preference, Pre HE, HE? Running, turns over? Parts? Budget? Looking for a car with it?
frenchyd said:Paul_VR6 (Forum Supporter) said:I have a marketplace notification setup for v12, I kinda want one now
Too bad, I coulda brought you one during the Christmas break. I went through PA to pick up my fender flairs.
Should I be looking around for you? Any preference, Pre HE, HE? Running, turns over? Parts? Budget? Looking for a car with it?
I wasn't paying any attention to locations and had it in my head Paul was in England until I saw just PA .....30 miles away. I may have just found my new dyno shop
Edit: wait....is there a dyno at the shop or do you have a place you go to?
mke said:grpb said:It is pedantry but worth saying, you still show relatively high pressure in the intake port at IVC, assuming that downward knee in the curve is the beginnings of reversion you still have intake charge inertia helping to pack more charge into the cylinder. I don't think it's necessarily past the ideal IVC (for output at that rpm), you're just in the region where you're trading intake charge for compression. No substitue for dyno time on that one.
It's a good looking torque curve, if it does that in real life I wouldn't touch a thing, I would not worry and be happy. Kudos to you for doing real engine development as a private individual, it's a long hard road.
Basically...I don't have the software key but I found this in my saved stuff, it looks like I was playing with tuning for max hp so I would have moved the lobe centers (I casn set them where ever I please in the real engine so I spent a lot of time looking at this) along with changing header design and velocity stack length, but this is again at 9k
I'm not sure what I was playing with, but bottom graph, green line is intake velocity at the valve and you can see it go negative just before the valve closes....that is reversion.
Here's another graph that includes a trapped mass line (green line bottom graph). No reversion here but the flow has stopped...so reversion was coming. That pressure comes from velocity of the charge in the port and stack being converted to pressure along with a pressure wave ideally hitting valve as it closes.
I can't find a good graph, but here a table with the info. The columns on the right break down total charge loss and where it went whether reversion or out the exhaust or spoilage (exhaust left in the cylinder)....you can see at idle 20% of the charge it coming back out the intake.
To see that in detail shows me what you were saying and that was a light bulb moment for me.
I've met a few cam grinders in my life and some just seem to want to sell you a cam without really understanding what I was trying to achieve.
You've been able to clarify the how and why. Thank you so much.
mke said:yupididit said:5 gallons of oil?
Dry sump no doubt, my car is 15 quarts.
I must've missed that part. Impressive.
mke said:Paul_VR6 (Forum Supporter) said:I have a marketplace notification setup for v12, I kinda want one now
Everybody needs at least 1 V12! ....but choose wisely
I had a v12 Mercedes that I got for free and had it running for $46 worth of fuel pumps. The biodegradable wiring harness was giving me hell so I sold it. Looking for another w140 v12 though 96+only. Then last year, I picked up a running v12 XJS for a couple hundred, sold it to a GRM folk cause I got an assignment to DC. I'm going to try and wait 5 years so I have to worry about moving. My alerts are active though lol
frenchyd said:To see that in detail shows me what you were saying and that was a light bulb moment for me.
I've met a few cam grinders in my life and some just seem to want to sell you a cam without really understanding what I was trying to achieve.
You've been able to clarify the how and why. Thank you so much.
Yes, good software helps take the mystery out....still no substitute for actual testing but its a huge help in pointing the way.
I should have my DM6 key back in a few days, then I will plug a jag V12 in using the HE head flow numbers as that is all I have and we can stop guessing about what the changes you're talking about will do.
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