Engine Masters challenge in Pop Hot Rodding

[1bolt]

Looking over popular hot rodding's Engine Master Challenge issue it struck me how many of the techniques used on these engines could be applied to our 280+ cube I6's... If 300 cube and 400 cube Normally aspirated V8's can pull over 500 hp without any power adders, just from seriously tricked out building tricks and techniques, then I wonder what the potential is for our I6 using some of those same ideas? For anyone not familiar they take max 500ci motors and test them against each other using whatever engines the builders choose, no blowers or juice. Must have flat tappet cam/Lifters and they are graded on a curve based on displacement. They also must develop very good low end torque and have a fat and flat power band to get good scores. So they don't just hog everything out shooting for a peak horse power number. Most of them are putting out 500+ pound feet.

Now granted a stroker is already putting out more HP and Torque than comparable stock V8's so it's ALREADY benefiting somewhat from the most basic hot rodding "tricks" like stroking, high compression ratio etc. Of course It's also got some basic design disadvantages for purposes of maxing out power. Like the lack of cross flow. and the straight up valve angle, there's no "wedge" to help make the intake port a straighter shot.

Some of the ideas are applicable though;

Tuning the intake runners and plenum size (pull the HP peake down into the most useable range)
TB mods that mimic the carb mods
Porting the head and intake.
keeping the intake as cool as possible, with a heat shield
building for perfect quench with high compression to maximum power without detonation.
Windage tray
Flipping the piston from the Factory (quiet and less power) to the higher performance and noisy during warm up.

A couple more radical ideas that spring to mind are:

Offset decking the head to cant the Intake valves toward the ports (obviously can only do this within the limits of the head surface thickness) every degree helps breathing.
Machining the intake and exhaust interface to angle both upwards slightly decreasing the angle (straighter shot).
filling the bottom of the intake port and raising the roof to straighten the port out for the new valve angle and intake runner angle.
Phenolic spacer for the intake, problem here is the best phenolic is G-7 and tolerates only 465* which might be enough... but maybe not, with the exhaust so close.
Aerodynamic crank (knife edging)
Turning the main and rod journals smaller for smaller bearings (lower parasitic friction losses)

[Flash]

Looking over popular hot rodding's Engine Master Challenge issue it struck me how many of the techniques used on these engines could be applied to our 280+ cube I6's... If 300 cube and 400 cube Normally aspirated V8's can pull over 500 hp without any power adders, just from seriously tricked out building tricks and techniques, then I wonder what the potential is for our I6 using some of those same ideas? For anyone not familiar they take max 500ci motors and test them against each other using whatever engines the builders choose, no blowers or juice. Must have flat tappet cam/Lifters and they are graded on a curve based on displacement. They also must develop very good low end torque and have a fat and flat power band to get good scores. So they don't just hog everything out shooting for a peak horse power number. Most of them are putting out 500+ pound feet.

Now granted a stroker is already putting out more HP and Torque than comparable stock V8's so it's ALREADY benefiting somewhat from the most basic hot rodding "tricks" like stroking, high compression ratio etc. Of course It's also got some basic design disadvantages for purposes of maxing out power. Like the lack of cross flow. and the straight up valve angle, there's no "wedge" to help make the intake port a straighter shot.

Some of the ideas are applicable though;

Tuning the intake runners and plenum size (pull the HP peake down into the most useable range)
TB mods that mimic the carb mods
Porting the head and intake.
keeping the intake as cool as possible, with a heat shield
building for perfect quench with high compression to maximum power without detonation.
Windage tray
Flipping the piston from the Factory (quiet and less power) to the higher performance and noisy during warm up.

A couple more radical ideas that spring to mind are:

Offset decking the head to cant the Intake valves toward the ports (obviously can only do this within the limits of the head surface thickness) every degree helps breathing.
Machining the intake and exhaust interface to angle both upwards slightly decreasing the angle (straighter shot).
filling the bottom of the intake port and raising the roof to straighten the port out for the new valve angle and intake runner angle.
Phenolic spacer for the intake, problem here is the best phenolic is G-7 and tolerates only 465* which might be enough... but maybe not, with the exhaust so close.
Aerodynamic crank (knife edging)
Turning the main and rod journals smaller for smaller bearings (lower parasitic friction losses)

You have put a lot of thought in to this........and i like the concept of it all.
really like the idea of shaving the head and filling in the floor.........the only thought that i have is, will gravity keep the oil off of the rocker arm tip? and push rods would need to be clearanced

How about a custom equal length (alu) intake tube that was tuned for a set rpm??????

Flash

[1bolt]

I think the 99+ intake is good enough to keep up with the best of heads. If we could get a "magic" CNC ported head for our I6 like Small blocks all have these days (AFR's for SBF 302's for example which create nearly 100 hp over stock 302 heads) then we would definitely need a more advanced intake... or maybe just an extrude honed 99+ to increase the runner cross section.

Truth is there's probably not enough meat in the head surface to get more than a couple degrees of wedge. And then you'd have to sleeve and re drill the head bolt holes the same amount, and hope that didn't create a significant weakness.

If it were possible and that's a big if. You then plane some off the intake mani interface surface so that you've reduced the 90* bend that happens from the port face to the valve seat.

I don't know how much you could straighten it out or how much a few degrees would benefit. But my guess is that it would be significant, the difference between the Renix and HO head is not that great I've never measured it though. It can't be more than a few degrees straighter even if the port was moved upwards an inch.

This stuff really fascinates me but it's probably ridiculously impractical Then again if Barney Navarro thought the AMC 199 was worthy of 30 PSI and 600 horses what do I know... I think his approach is certainly something we can learn from though... Instead of trying to finess it in, cram it in with brute force, and charge cooling.

I wonder what his compression ratio, cam, and quench spec was...

[Flash]

I have always know that when match porting, the top and side of the port are the most important and NEVER PORT THE FLOOR................This discussion just paint a much clearer picture of why it's important!

Flash

[1bolt]

I'm no expert on this stuff either, just sharing what I thought was very interesting stuff. As far as I know the ideal intake port would be a straight line going down the valve. But of course there are small things like Hoods and Valve springs etc. in the way. However with that limitation in mind anything that reduces the curve of the port is going to increase velocity and reduce pumping losses. Which is what those Engine builders are all trying to do. Hell thats the only thing they CAN do really, without turbos or Juice.

I think there's a lot to be learned if engine builders can make normally aspirated small blocks put out 500 to 600 horse power JUST by building with experience and know how and every trick in the book.

They are getting those impressive numbers by using every single possible edge, and trick, to get power that is more than the sum of the parts.

If you look at their numbers they are roughly double to 2.25 times the output of the same engines stock. In some cases even two and a half times more power. That's insane if you ask me...

To put that in perspective that would be like taking a 4.0 at 190 factory rated hp and rebuilding it to make 400 to 450 hp without stroking it! Crazy eh?

I may be a dreamer but if you can double up a small block V8 I bet the same tricks can do at least 1.5 times the power of a normal 4.0 which would be 285hp! Imagine that build with stroking in the equation

[gradon]

I enjoy all this discussion as it makes you think out the reason/physics behind how the setup is/was made originally and what variables you can influence to make more efficient/optimal(to your liking). Sometimes things align by fluke, but having the knowledge and applying it is always a plus.

[John]

I think the 99+ intake is good enough to keep up with the best of heads. If we could get a "magic" CNC ported head for our I6 like Small blocks all have these days (AFR's for SBF 302's for example which create nearly 100 hp over stock 302 heads) then we would definitely need a more advanced intake... or maybe just an extrude honed 99+ to increase the runner cross section.

Truth is there's probably not enough meat in the head surface to get more than a couple degrees of wedge. And then you'd have to sleeve and re drill the head bolt holes the same amount, and hope that didn't create a significant weakness.

If it were possible and that's a big if. You then plane some off the intake mani interface surface so that you've reduced the 90* bend that happens from the port face to the valve seat.

I don't know how much you could straighten it out or how much a few degrees would benefit. But my guess is that it would be significant, the difference between the Renix and HO head is not that great I've never measured it though. It can't be more than a few degrees straighter even if the port was moved upwards an inch.

This stuff really fascinates me but it's probably ridiculously impractical Then again if Barney Navarro thought the AMC 199 was worthy of 30 PSI and 600 horses what do I know... I think his approach is certainly something we can learn from though... Instead of trying to finess it in, cram it in with brute force, and charge cooling.

I wonder what his compression ratio, cam, and quench spec was...

Barney's motor has fascinated me for years, here is a wealth of info from a owner of one of the gems, including cam specs, I have the cam specs worked out into desktop dyno and it makes a educational variation. http://wps.com/AMC/Navarro-turbo-motor/
Enjoy
John
J

[Flash]

I think the 99+ intake is good enough to keep up with the best of heads. If we could get a "magic" CNC ported head for our I6 like Small blocks all have these days (AFR's for SBF 302's for example which create nearly 100 hp over stock 302 heads) then we would definitely need a more advanced intake... or maybe just an extrude honed 99+ to increase the runner cross section.

Truth is there's probably not enough meat in the head surface to get more than a couple degrees of wedge. And then you'd have to sleeve and re drill the head bolt holes the same amount, and hope that didn't create a significant weakness.

If it were possible and that's a big if. You then plane some off the intake mani interface surface so that you've reduced the 90* bend that happens from the port face to the valve seat.

I don't know how much you could straighten it out or how much a few degrees would benefit. But my guess is that it would be significant, the difference between the Renix and HO head is not that great I've never measured it though. It can't be more than a few degrees straighter even if the port was moved upwards an inch.

This stuff really fascinates me but it's probably ridiculously impractical Then again if Barney Navarro thought the AMC 199 was worthy of 30 PSI and 600 horses what do I know... I think his approach is certainly something we can learn from though... Instead of trying to finess it in, cram it in with brute force, and charge cooling.

I wonder what his compression ratio, cam, and quench spec was...

Barney's motor has fascinated me for years, here is a wealth of info from a owner of one of the gems, including cam specs, I have the cam specs worked out into desktop dyno and it makes a educational variation. http://wps.com/AMC/Navarro-turbo-motor/
Enjoy
John
J

Thanks John, grate read..........sure would love to see the roller lifters used in that one............Even if they were mechanical instead of Hyd

Vary interesting cam spec......to bad there at .050 spec instead of seat to seat......

Flash

[1bolt]

awesome link, I just read the retrospective on him in Hot Rod this evening, I've always wondered if more info about that motor was out there.

A couple things that really interest me are his tendency to go small displacement and high durability so he could boost the shit out of the engine.

Basically the exact opposite of conventional wisdom which says you make it bigger until you need stronger parts, and then you force induction if you need more power... at which point you need even stronger bigger parts.

There's plenty of support for the smaller more durable direction. If the motor is physically stronger you can increase boost, but increasing displacement creates weakness (proportionally thinner castings, longer wider dimensions, larger open spaces). The bigger journal overlap on the shorter stroke cranks he used contributed to this durability as well.

I sound like I'm making an argument for "tuners" but this is why there are 8 second 4 cylinders out there.

[Shark]

a "magic" head would be great. especially if it were affordable. are the "degrees of wedge" your talking about allowing the air/fuel mix to enter the cylinder at a better angle by entering from more above than from the side? too bad we'll probably never see a manufacturer get excited enough about the jeep 4.0 aftermarket to actually produce such a head.

what is a phenolic spacer?

[1bolt]

Yep the less the air flow has to curve the less restricted your engine breaths. By making a head wedge shaped you put the valve at an angle that allows the intake port to become closer to a straight shot down the stem.

We will definitely never see anyone more excited than HESCO and their Aluminum head, it is a shame, another couple years, or maybe even a redesign of the I6 and the market in Jeeping may have been big enough to support more than a few specialty shops like HESCO... The truth is though we're trying to hot rod an engine meant to put Jeeps over rocks which the aftermarket has done a great job with.

It's fun but there are definitely practical limits to how far we can get for a reasonable cost.

Still I'd love to tear down my local strip with a 500hp I6 in a Comanche. I think if I ever manage it, it will be with E85 super high compression and a Turbo though. That plan doesn't get serious front burner attention until a couple stations in my area start providing E85.

[John]

With the last link to The Navarro motor you have a rare opportunity to look at one of the more advanced builds on the I6, and through the magic of photo shop (and others) you can look at the components, Look inside at portions of the porting job, examine the camshaft, view the work on the combustion chambers,
View this link and see a completed Navarro I6, and there is still much more to learn from these views.
John

http://wps.com/AMC/Navarro-Indy-motor/index.html

[1bolt]

Yeah I'm kinda floored at how bone stock everything appears. The crank has no visible mods, the block looks like every 232 199 and 258 block I've ever seen... In other words not much webbing, and no special (visible) mods to make it stronger.

How in the hell did Navarro turn that thing at 6,000 and 7,000 RPM's with the long Cam shaft? How did the cam survive the roller lifters? I don't see anything inside that block that would seem to address the Cam shaft harmonic. Maybe the "massive fuel pump" which is mounted on the end of the cam is also acting as a harmonic dampener? Killing two birds with one stone? As far as I know that 199 will have the same Cam harmonic as a 258 and 242 block

You know besides the very ported head and the turbo setup it looks like Navarro just threw massive boost pressures at it with massive amounts of high octane race fuel, and let the boost do all the work. He de-stroked it, and the bore (judging from the displacement) is stock.

I'm also disapointed that the guy didn't get any rods, so we don't know any internal dimensions, and no quench spec.

[John]

But you do see a motor that ran solid lifters, has a thorough blueprinting of the block, a crankshaft that is covered with signs of a extreme balancing, whose block needed cut to a depth of about 1/2 inch for valve clearance of intake and exhaust valves, a nice overlap pattern cam shaft. A head with a shallow, beautiful polished combustion chamber. Intakes, valve shape, port and polishing, contouring and general shape of intake manifold, tuned length of exhaust system bring details of a design for high velocity balanced system working with the cam to point to the efforts of a scavenging system to enhance the efficiency of bringing lots of fuel to the fire within. Attention to detail.
Yeah our blocks are strong as hell. The head is strong enough, the inlet and exhaust ports can be improved on quite a bit, a intake , exhaust that is well thought out can greatly improve its performance. One very well thought out build, concentrating on velocity throughput, good scavenging and lots of air and fuel.
John

[John]

By the way he didn't destroke it as all 199's had a 3 inch stroke, but he did reduce bore diameter.
John