Reduction Of Friction
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Joined: Oct 2002
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From: Upstate NY
Re: COST
Originally posted by TIMEBANDIT
The engineer stated that the total cost difference bewteen the 2 types of developmental engines is about 200 dollars. This was the difference in the cost of the bearings since both engine types required all the bearings and their dimensions be special order. And by the way the cost of one of these R&D engines is around 40 grand so 200 bucks isn't a big deal.
Special order
4 main bearings
6 rod to main bearings
8 cam bearings 4 for each head
6 rod to wrist pin bearings were standard production type used in their 2 stroke motors already.
He felt like the difference in cost between the 2 types of engines at a mass producion facility would be about a 70 to 80 dollars. And most of that would be the cost difference in the bearings and cages compared to the regular automotive bearings.
And its funny how things are done in R&D
They were told build an engine to the following specs
300 hp at 6000 rpms
Vertical engine
4 stroke
Direct fuel injected
2 or 4 valves per cylinder they ended up with 4
max displacement 3.0 liters
Max weight finished 275lbs (which means aluminum block and heads)
Max assembly line cost 10,000 including the lower unit which costs about 4,000 leaving 6,000 for the engine.
He said that they have managed everything but the weight and cost issues they are coming in consistantly at around 295lbs with a predicted cost of about 6200 dollars.
The engineer stated that the total cost difference bewteen the 2 types of developmental engines is about 200 dollars. This was the difference in the cost of the bearings since both engine types required all the bearings and their dimensions be special order. And by the way the cost of one of these R&D engines is around 40 grand so 200 bucks isn't a big deal.
Special order
4 main bearings
6 rod to main bearings
8 cam bearings 4 for each head
6 rod to wrist pin bearings were standard production type used in their 2 stroke motors already.
He felt like the difference in cost between the 2 types of engines at a mass producion facility would be about a 70 to 80 dollars. And most of that would be the cost difference in the bearings and cages compared to the regular automotive bearings.
And its funny how things are done in R&D
They were told build an engine to the following specs
300 hp at 6000 rpms
Vertical engine
4 stroke
Direct fuel injected
2 or 4 valves per cylinder they ended up with 4
max displacement 3.0 liters
Max weight finished 275lbs (which means aluminum block and heads)
Max assembly line cost 10,000 including the lower unit which costs about 4,000 leaving 6,000 for the engine.
He said that they have managed everything but the weight and cost issues they are coming in consistantly at around 295lbs with a predicted cost of about 6200 dollars.
Great info!
Now 100 hp/L @ 6k is a challenge, and it's about 45% more /L than the Northstar @ the same rpm. The big problem is that 300 hp @6000 is about 263 ft-lbs @ 6000. That's 87.5 ft-lb/L which is like 500 lb-ft on a 350 SBC @ 6000. That, IMO is even more difficult than the 100 hp/L for a long-durability OEM engine.
I've been doing some simulations on a 3L V6 tonite, and have achieved about what they did, but it's an edgy engine. The only way I got close was to tune for torque peak @6000, which involved VE over 107%. The head flow needed would easily allow 8000 rpm and lots more hp. Interestingly I ended up with good flowing heads, a fairly high DCR and a very mild cam with lots of lift to utillize the flow numbers. I couldn't do it without rocker arms so I could use an inverted flank cam. How did they do it?
I was surprised at the high cost of the engine. I assume the 6000 is selling price, not factory cost. You wouldn't want to know how that compares to the cost of a 300+ hp Northstar. GM won't say, of course, but from what I know, it ain't anywhere near 6 large.
IMO, the reduction in friction with rollers, if it really added the last 20 hp or so, was necessary to reach their target. My simulation had total friction hp about 28 @ 6200 and 35 @ 7000.
I'll bet they limit the production engine to less than 6500 for durability. Folks that want to get more shouldn't have too much trouble.
My $.02
Thread Starter
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Joined: Jun 2003
Posts: 50
From: Louisiana
Scary
Stroker its almost scary how close you came to their numbers.
They used an over head cam in each head with 4 lobes per cylinder the 2 outside lobes actuate the 2 intake valves via rocker arms and the 2 center lobes actuates the exhausts valves via opposite offset rockers. He said idle quality is good at about 750 rpm which is where their 2 stroke version idles at.
The redline will be 6200 rpms for the Standard production engine and 6600 for their ProMax performance version. And you are dead on with the heads. They took one of the roller motors and ran it all the way to 7,000 then realized it was leaning out and had to add some larger injectors remaped it and started again. It pulled hard all the way to 8,000 and was left their for about 10 min before common sense took over and they backed out of it. But He said the numbers were impressive.
And 6k is the retail cost but he wouldn't give me their mark up percentage.
He also said that the rods were over sized for the roller application for comparison purposes to the standard bearing engine and they will probably be able to use a smaller crank rod journals and lighten up their rods some more prior to production.
All in all its a pretty impressive engine considering what its capable of. The torque and power curve is almost similar to what a dominion head 350 would be if you cut 2 cylinders off of it with 1.3 less liters.
They used an over head cam in each head with 4 lobes per cylinder the 2 outside lobes actuate the 2 intake valves via rocker arms and the 2 center lobes actuates the exhausts valves via opposite offset rockers. He said idle quality is good at about 750 rpm which is where their 2 stroke version idles at.
The redline will be 6200 rpms for the Standard production engine and 6600 for their ProMax performance version. And you are dead on with the heads. They took one of the roller motors and ran it all the way to 7,000 then realized it was leaning out and had to add some larger injectors remaped it and started again. It pulled hard all the way to 8,000 and was left their for about 10 min before common sense took over and they backed out of it. But He said the numbers were impressive.
And 6k is the retail cost but he wouldn't give me their mark up percentage.
He also said that the rods were over sized for the roller application for comparison purposes to the standard bearing engine and they will probably be able to use a smaller crank rod journals and lighten up their rods some more prior to production.
All in all its a pretty impressive engine considering what its capable of. The torque and power curve is almost similar to what a dominion head 350 would be if you cut 2 cylinders off of it with 1.3 less liters.
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Joined: Oct 2002
Posts: 2,931
From: Upstate NY
Re: Scary
Originally posted by TIMEBANDIT
Stroker its almost scary how close you came to their numbers.
He said idle quality is good at about 750 rpm which is where their 2 stroke version idles at.
Stroker its almost scary how close you came to their numbers.
He said idle quality is good at about 750 rpm which is where their 2 stroke version idles at.
Cam was 196/200 @ .050 on a 106LSA with about .535 net lift. Lots of rocker ratio! That gave -14 degrees overlap @ .050. I don't realy like the 106, but I ran out of time/ambition to opitimize it last nite.
What would really be cool would be more engine specs and flow numbers. I'm just doing rectal extractions here. There are a fair number of 500 cc/cylinder engines out there to plagarize. 3.5 bore, 3.2 stroke, 10:1 static CR, 5.7 in rods (1.78 r/s). I really wanted to go a little more overquare to help it breathe, but vertical height is probably critical.
Oil must be dry sump, and my sim shows that some intake and exhaust tuning helps get the torque peak about 6k.
I wonder who designs and builds their development cams. I know where/who I'd pick.
This is a fun exercise.
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Joined: Jul 2003
Posts: 59
From: Houston
OldSStroker,
About ring drag. Next time you are building an engine try this.
Take a piston with 1/16, 1/16, 3/16 rings install the top ring and place in the finished bore and use a fish scale or similar device and measure the force required to pull the piston through the bore. Now install the second ring and remove the top ring and repeat. Finally install only the oil ring package and test. Then use a piston with .043, .043, 3mm low tension rings and repeat the above test and see how much difference it makes. The big gains we find in rings comes from adjusting the tension of the oil expander spring until it is just tight enough to keep the engine from smoking.
Yeah, Deffinitely HP is airflow limited. Torque is directly related to engine displacement and cylinder pressure. If you want to increase torque without increasing cylinder pressure you increase the displacement. More lever arm from increased stroke or more piston surface area from bigger bore. Of course torque is related to airflow also but not to the extent that hp is limited by it. A NA engine is only able to produce so much tq per cube but with better and better cylinder heads along with optimized cam timing you can hold on to your cylinder pressure to higher rpm's creating more hp. It would be pretty easy to build a large cubic inch engine with crappy heads and a small cam and make tons of torque. Look at the big blocks put in trucks back in the sixties and seventies. They had crap for heads and cams but by virtue of displacement they could make gobs of low end power but with the crappy heads and valvetrain they couldnt breathe well to the rpms needed to make good HP numbers.
Your exactly right in that when displacement is limited the best combinations for outright power are the big bore short stroke combos. They can make more power per cubic inch than small bore combos due to their increased breathing potential and since cost is usually not prohibitive for these types of teams they can afford the parts and research required to keep the valvetrain together.
I have heard that one or two Cup teams have made the smaller bore combo's work but it seems that by far the big bore is dominant in that class. And I agree with running the engine at the highest rpm that your heads will breathe efficiently to. If your not you are just leaving some power on the table.
I agree with what you said about the cup and f1 engines. That is the way to produce power. If I can make a little more torque at the same rpm I have increased power output. That just goes to show that higher rpm's are not always the answer. Improving the breathing efficiency and cylinder pressure will increase power without the need for more rpm. Of course making the same torque just at higher rpm's will make more power also but durability becomes more of an issue then. By the way I have heard that lately the biggest advances for one Pro Stock team have come strictly from advances in their valvetrain technology.
About ring drag. Next time you are building an engine try this.
Take a piston with 1/16, 1/16, 3/16 rings install the top ring and place in the finished bore and use a fish scale or similar device and measure the force required to pull the piston through the bore. Now install the second ring and remove the top ring and repeat. Finally install only the oil ring package and test. Then use a piston with .043, .043, 3mm low tension rings and repeat the above test and see how much difference it makes. The big gains we find in rings comes from adjusting the tension of the oil expander spring until it is just tight enough to keep the engine from smoking.
Yeah, Deffinitely HP is airflow limited. Torque is directly related to engine displacement and cylinder pressure. If you want to increase torque without increasing cylinder pressure you increase the displacement. More lever arm from increased stroke or more piston surface area from bigger bore. Of course torque is related to airflow also but not to the extent that hp is limited by it. A NA engine is only able to produce so much tq per cube but with better and better cylinder heads along with optimized cam timing you can hold on to your cylinder pressure to higher rpm's creating more hp. It would be pretty easy to build a large cubic inch engine with crappy heads and a small cam and make tons of torque. Look at the big blocks put in trucks back in the sixties and seventies. They had crap for heads and cams but by virtue of displacement they could make gobs of low end power but with the crappy heads and valvetrain they couldnt breathe well to the rpms needed to make good HP numbers.
I too like big displacement street engines to achieve torque/power/cost goals. But, when winning a race is critical, and rules limit displacement, but not cost, I don't see the lower rpm/longer stroke engines winning. I believe I understand your point, but I don't see the state-of-the-art racing classes doing this. Just the opposite. Why is that, do you think?
What I do see is rpm at the highest point that the limiting port velocity will support (with durabilty factored in, of course), with big bore/short stroke configurations. Even in restricted Cup engines, I don't believe the bore/stroke change much (from unrestricted), but the rpm drops maybe 1500+ due to airflow limits. I notice, via TV telemetry, that Cup "plate" engine speeds seem to rise a tad each season.
I agree with what you said about the cup and f1 engines. That is the way to produce power. If I can make a little more torque at the same rpm I have increased power output. That just goes to show that higher rpm's are not always the answer. Improving the breathing efficiency and cylinder pressure will increase power without the need for more rpm. Of course making the same torque just at higher rpm's will make more power also but durability becomes more of an issue then. By the way I have heard that lately the biggest advances for one Pro Stock team have come strictly from advances in their valvetrain technology.
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Joined: Jul 2003
Posts: 59
From: Houston
Bret.
I guess I kind of stray from the point in some of my posts.
Yeah if I want to make the same power at the same rpm with a cubic inch limit then either combination will come out pretty close to the same. As a matter of fact in that situation the advantage would probably go to the big bore short stroke engine as it would have less friction at the same rpm and less inertial loads at the same rpm. Since pretty much all I am concerned about is racing engines I tend to always think of things from the point of maximizing power output and with the larger bore airflow increases and power potential goes up. So usually with the big bore combo I will be turning it higher to take advantage of the extra airflow I can get from the heads.
I always try to look at cylinder head airflow in relation to bore size and piston speed. If I increase the airflow ability of my heads on my current bore size the piston speed that head will support on that bore will go up. If I want to increase piston speed with the same stroke rpm will have to go up. And I never said you want to run your engine at the limiting piston speed of the heads you have I was just trying to say that you certainly wouldnt make any more power beyond that point. Whether my limiting port velocity is due to separation over the short turn or wet flow problems I will still try to run the heads as close to that limit as possible to maximize power output.
Oh yeah and on the bearing coatings I was talking about closing up the clearance by .0003-.0004 . If we already have 1 bearings in and the clearance is still a little bigger than we would like the coatings can take up a little clearance.
I guess I kind of stray from the point in some of my posts.
Yeah if I want to make the same power at the same rpm with a cubic inch limit then either combination will come out pretty close to the same. As a matter of fact in that situation the advantage would probably go to the big bore short stroke engine as it would have less friction at the same rpm and less inertial loads at the same rpm. Since pretty much all I am concerned about is racing engines I tend to always think of things from the point of maximizing power output and with the larger bore airflow increases and power potential goes up. So usually with the big bore combo I will be turning it higher to take advantage of the extra airflow I can get from the heads.
I always try to look at cylinder head airflow in relation to bore size and piston speed. If I increase the airflow ability of my heads on my current bore size the piston speed that head will support on that bore will go up. If I want to increase piston speed with the same stroke rpm will have to go up. And I never said you want to run your engine at the limiting piston speed of the heads you have I was just trying to say that you certainly wouldnt make any more power beyond that point. Whether my limiting port velocity is due to separation over the short turn or wet flow problems I will still try to run the heads as close to that limit as possible to maximize power output.
Oh yeah and on the bearing coatings I was talking about closing up the clearance by .0003-.0004 . If we already have 1 bearings in and the clearance is still a little bigger than we would like the coatings can take up a little clearance.
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Joined: Jul 2003
Posts: 59
From: Houston
Oh yeah and If I keep the bore and heads the same and increase the stroke my peak power will be higher and the rpm it occurs at will be lower. By lowering the rpm of the engine the peak piston speed can even be slightly higher. In the end its quite possible to end up with less friction and more power by increasing the stroke and therefore the displacement of the engine.
And while it is true that at a set rpm the short stroke crank will have less friction and less inertial loads it is not necessarily that way at the same piston speeds. The short stroke crank will have higher inertial loads at the same piston speed due to the difference in the rate of accel and decel and the frequency of the change in direction of the piston. This is the same reason ring flutter is more related to rpm than piston speed.
And while it is true that at a set rpm the short stroke crank will have less friction and less inertial loads it is not necessarily that way at the same piston speeds. The short stroke crank will have higher inertial loads at the same piston speed due to the difference in the rate of accel and decel and the frequency of the change in direction of the piston. This is the same reason ring flutter is more related to rpm than piston speed.
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Yeah agree with you on that.
"In the end its quite possible to end up with less friction and more power by increasing the stroke and therefore the displacement of the engine."
That might be a stretch, definately more or the same power at a lower RPM, and MAYBE on the friction. You would have to have a much lower peak to have less friction with a shorter stroke.
Bret
"In the end its quite possible to end up with less friction and more power by increasing the stroke and therefore the displacement of the engine."
That might be a stretch, definately more or the same power at a lower RPM, and MAYBE on the friction. You would have to have a much lower peak to have less friction with a shorter stroke.
Bret
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From: Louisiana
Apply to Oem
Hey guys know what we have just done??????
We have just shown the oems how to make a 600hp N/A engine without radical technology, without sacrificeing idle quality, durability, or driveability, with very little increase in cost. And it would be virtually bullet proof.
And we didn't stray to far outside the box.
If you apply the items discussed in this thread to a 400 destroked to a 377 and extrapolate the numbers you end up with a 600 hp N/A engine.
We have just shown the oems how to make a 600hp N/A engine without radical technology, without sacrificeing idle quality, durability, or driveability, with very little increase in cost. And it would be virtually bullet proof.
And we didn't stray to far outside the box.
If you apply the items discussed in this thread to a 400 destroked to a 377 and extrapolate the numbers you end up with a 600 hp N/A engine.
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Joined: Aug 2003
Posts: 520
From: Michigan is a decent state.
Re: Apply to Oem
Originally posted by TIMEBANDIT
Hey guys know what we have just done??????
We have just shown the oems how to make a 600hp N/A engine without radical technology, without sacrificeing idle quality, durability, or driveability, with very little increase in cost. And it would be virtually bullet proof.
And we didn't stray to far outside the box.
If you apply the items discussed in this thread to a 400 destroked to a 377 and extrapolate the numbers you end up with a 600 hp N/A engine.
Hey guys know what we have just done??????
We have just shown the oems how to make a 600hp N/A engine without radical technology, without sacrificeing idle quality, durability, or driveability, with very little increase in cost. And it would be virtually bullet proof.
And we didn't stray to far outside the box.
If you apply the items discussed in this thread to a 400 destroked to a 377 and extrapolate the numbers you end up with a 600 hp N/A engine.
but I still dont buy into this destroking bit, not to make more power. I guess I'll find my own path, but this is my humble meaningless opinion right now.
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Posts: 6,518
Trey,
A 6.18L motor with a 100hp/L is what he is talking about. Basically he's taking the easy route with a destroked 400, since that get's him a big bore and around the cubes he is looking for.
A 600HP N/A motor that will hold up to a 100,000 mile durability test is not going to be easy, but I would like to see it.
Bret
A 6.18L motor with a 100hp/L is what he is talking about. Basically he's taking the easy route with a destroked 400, since that get's him a big bore and around the cubes he is looking for.
A 600HP N/A motor that will hold up to a 100,000 mile durability test is not going to be easy, but I would like to see it.
Bret
On permanent vacation
Joined: Aug 2003
Posts: 520
From: Michigan is a decent state.
Originally posted by SStrokerAce
Trey,
A 6.18L motor with a 100hp/L is what he is talking about. Basically he's taking the easy route with a destroked 400, since that get's him a big bore and around the cubes he is looking for.
A 600HP N/A motor that will hold up to a 100,000 mile durability test is not going to be easy, but I would like to see it.
Bret
Trey,
A 6.18L motor with a 100hp/L is what he is talking about. Basically he's taking the easy route with a destroked 400, since that get's him a big bore and around the cubes he is looking for.
A 600HP N/A motor that will hold up to a 100,000 mile durability test is not going to be easy, but I would like to see it.
Bret
I didn't see the OEM the first time I read it.
I'll agree that short stroke big bore will make more power/displacement, that that it means much
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Joined: Jul 2003
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From: Houston
If you apply the items discussed in this thread to a 400 destroked to a 377 and extrapolate the numbers you end up with a 600 hp N/A engine.
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Joined: Jan 2003
Posts: 24
wow, wow, just doing some reading of some old posts. lots of learning stuff....except a question pops into mind which is by far, out of my hands of being able to figure out. I would say i understand all statements based on bore and stroke hp, tque, friction, etc. But, all of these claims, as far as peak hp production range and peak torque production range based on piston speed and bore are all based on the assumption that your flow into your motor is based on valves. I think i said that to where it is understandible. If not, post and i will try to reword it. MY QUESTION: Is all this still true if you envisioned a motor capable of flowing air into the motor as if it had a giant hole over the center of the cylinder at almost the entire width of the bore, only when intake air is need to enter, and only when exhaust is needed to exit. Would it still be characteristic to produce more power, based on larger flow, based on larger bore sizes....or would a super long stroke ( just for comparison reasons) then be able to suck so much air, simply based on the ability fill the cylinder practically 100% be able to produce massive power because of the extreme volumetric efficiency occuring. The head design i am theorizing about would be...hmmmm.....similar to a valved motors flow, but more equivalent of being able to have an single valve able to share intake and exhaust flow, have that valve centralized over the cylinder, have it be almost as big as the cylinders bore, but have the flow characteristics into the cylinder of a valve not actually being there at all (i. e. the incoming/exiting flow would not have to go around the valve.) I dont know if anyone can bare with me on this theory, and can answer the resulting power outputs based on a short stroke/big bore motor, versus a longstroke/small bore motor. I am also thinking that you would be able to have a lighter piston in a smaller bore?...
Any response would be great, thanx.....haha...respond if u dare....!
Any response would be great, thanx.....haha...respond if u dare....!
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Joined: Jan 2003
Posts: 24
oh yeah, my whole lil theoreticall idea of the extreme flowing head, dont factor in any valvetrain components....uhm this whole thing is based off of a concept valvetrain/head design i am brainstorming, uhm, i havent been able to make some visits to the patent office to see what patents exist similar to my idea, so i am trying not to get into extreme details at all, but if anyone could comment on my previous inquiries, that would be awsome. Basically, the design eliminates the valvetrain, pretty much like the coates engine http://www.coatesengine.com/ , but far superior. yeah, so my previous posts question would be with almost zero friction from any sort of top end valvetrain, but yeild flow characteristics essentially similar to a hole practically the size of the bore...