I think JDM builds great motors from everything I have read over the years - it has been proven by a lot of satisfied customers. After reading about Rob's new motor and other threads, I got a kick out reading reading about the power some tuners/builders are making with lower amounts of boost, very conservative timing - higher compression correct?

{ I truly can't believe how awesome the #'s are, a frigging 10 degree 17 lb Winter Program
with more HP than I had hitting it with a hundred shot. }

Here is a quote from a previous thread:

We offer our engines in 9:1 comp, 9:5 comp, 10:1 comp, and 12:1 comp. We have had all these combos out there running for years. Example Paul Gaminos F150 is a 5.4 4v NA motor running 12:1 that we built. We have done testing with 9:1 and 9.5:1 in the Lightning truck. We test these things for months before we even make a decision on if we are going to offer it.

Our Aluminum 4V versions are 10:1, I will answer any and all questions you need to know about our shortblocks.

Jim@JDM

Higher boost + Lower Compression or Lower boost + Higher compression. Curious what the compression ratios are in other builders motors? With running higher compression, will this ultimately decrease the amount of boost you can run compared to others that are running on stock 8:4:1 compression motors?

By the way this is not meant as a bash to JDM or Rob.

 

Low boost supercharged engines are becoming a thing of the past. The reason why is today's technology on cam grinds, the way air flows in and out of the new designed cylinder heads, combustion chamber design, and last but not least the design of the tops of the piston. Also todays tuning capabilities play a roll.

One of the reasons why our motors make good power, have great idel quality, and kick A$$ throttle response, is our port design for the heads and our camshafts. This is something we have just put into all our motors in the last 3 months. I cant give you all the specs on our cams but I can tell you they only have a .520 lift both intake and exhaust. We have been running spring pressures closed at 105lbs. Thats still not good enough so we just payed for tooling to have the springs able to be setup for 125lbs. Now this is the most we can go with our spring pocket design. With all the R&D work we have done within the past two months, i feel any more than that will actually hurt you. Plus our new design of pistons raised the compression to a 9:1 ratio.

Ask Rob, Brian K,or Gator about how their trucks pull 14-15 inches of vaccumm at idle. Its because of the cams, back to back test on the dyno going from a standard off the shelf stage 3 cams to our new cams which is alot less aggressive we picked up 34 HP and 47 ftlbs of torque and the customers fuel economy picked up 3 MPG! With better throttle response. See in high boost applications you dont need a radical cam. Comp and Crower stage 3 cams are radical! The stage 2's are border line. Patriot heads when they come from the factory only have closed seat pressure at 75lbs. The minute you start the truck they are down to 70lbs. 70lbs is no good for anything over 14 psi of boost.

John from Accufab, his pro car runs 6.60's at 215 mph. His cams are only a .440 lift and runs a spring pressure of 120lbs. He runs 38lbs of twin turbo boost! These cams he runs are by no means an aggressive. This is why he can drive his 6 sec ride up to the staging lanes, while everyone else in his class needs a tow. His cam design is not dumping excessive amounts of backwash into the intake system. He can let his car sit and idle all day long at 800 RPMs and then pull the plugs and they are perfect. Again too big of a cam is extremley bad for the performance of our engines. Especially with high boost. You could blow your boost right out the exhaust before the engine gets a chance to use it. By the way John's car is 11:1 compression!

Jim@JDM

 

I just re read my post....

To let everyone know we do not use patriot heads, we tested them about a year ago and decided to use a local extremley reputable CNC machine shop who does our CNC work and the heads are assembled in house.

Jim@JDM

 

Very informative post Jim Keep up the great work.

 

45 years ago, most "conventional wisdom" at that time dictated low compression ratios with higher boost for maximum power withotu exploding - especailly on "fuelers." However, in the past few years, with increased knowledge of how combustion chamber's work, piston dome design, and camshaft design's coordinated with air flow through the valve system over an increased band rpm bandwidth - have led to engine designs utilizing compression ratios and boost levels higher than previously thought could be used without detonation - with resulting higher horsepower. So it's nice to see JDM offering supercharged higher compression ratio engines than often offered in the past - and offering some good info on here. And as he has a business - nothing wrong with promoting his success. I'm not sure I see the point in debating "who" has the most 10 sec machines out there. And of course there are many other top engine builders out there who "don't" post on these boards, but are known locally in their respective areas - but that doesn't take away from the success that JDM, JLP, and PSP all have had in building top running Lightnings.

PS: Although camshaft design is much much more sophisticated and advanced than 45 years ago, we knew to use a different camshaft for a supercharged engine than we would for a normally aspirated engine. Probably not many on here are familar with the Clay Smith or Chet Herbert camshaft designs.

 

I would like to thank Fast Specialties of Vancouver Washington for running all the dyno tests required back in September to help me prove the intake valve springs were floating when operating under high boost and high rpm. At the time NONE of the valve spring manufactures believed me, and the ONLY Lightning engine provider that had an ear for what I was saying was Jim of JDM as he has great insight into how these engines work. Jim with his engine program has taken the valve spring issue and turned it around and will have springs manufactured that will take the Lightning to new levels. The Lightning community should be greatful we have a vendor like JDM that has the insight and initiative and can make things happen.

This valve float issue is really quite interesting when you get into the physics of what is happening inside the engine that creates that issue. First off Ford used the same valve springs in the Lightning that they use in the NA engines so they are just barely strong enough to support proper valve operation to red line or about 5200 rpm in a NA engine.

Boost pressure has an effect on valve operation that is not obvious to the casual observer.
The 5.4L engine has a small bore and a very long stroke so the valves must have a small diameter to fit inside the bore. The Valve Area to Cylinder displacement ratio is therefore very low resulting in low volumetric efficiency particularly at high rpm. Because the volumetric efficiency drops off as RPM increases the cylinders do not completely fill with air. Lets say for instance that the engine has 50%(just a guess) volumetric efficiency at 5500 rpm. If this were the case and you were running 20-psi manifold pressure the cylinder pressure when the intake valve closes would be only 10 psi. That leaves 10-psi differential pressure across the intake valve, i.e., there would be 10 psi trying to open the intake valve. The Lightning intake valve has about 2.5 square inch of area so that works out to be about 25 pounds pressure trying to keep the valve from closing. Since we only have about 60 pounds spring pressure to start with subtracting 25 pounds from that low number is very significant to say the least and even if the engine had 75% VE the pressure created on the valve would still be significant. Once the valve begins to close late slack is created in the valve train causing the hydraulic lifters to pump up and power will drop off.

You can identify valve float in the dyno graph by looking for a “kink” in the power curve. For instance if the hp curve is going up and then makes an abrupt change in direction “kink” and starts down or starts going flat across that is the point where the valves begin to float. I send Rob (several months ago) his dyno chart marked up with a line pointing to where the valves were beginning to float. Rob, if you still have it perhaps you could post it here.

Charles

 

What I really find amazing about the spring manufacturers and the Lighthing is that they wouldn't listen ????
If you had a pushrod motor they would be all over it
Dale

 

Sounds like I have bagged a goodun then.

Built motor on frame in shop waiting for paint.
Mag Powers being assembled on bench as I write.

Well done the end result was well worth the wait.


Question to Rob - did you get your braking sorted out mate.

 

No : o (

I'm driving it 24/7 (schitt even in the rain) but there def something going on with the front brakes. The Pedal is back and it stops "ok" (I'm not driving around with no brakes) but it's extremely obvious the front brakes are NOT working right. I honestly couldnt power brake it right now if I wanted to, it'll just roll away on you (seems only the back brakes are working right ????.
But I can spin the tires from parkway speed, hehehehehe.....
I'm going to try and find someone with the stock Calipers and then do new Rotors Calipers Pads and bleed them again, if that doesnt fix it then the Master Cylinder, distribution / metering block (or what ever they call it) etc....

Charles if we ever get to FINALLY meet in person you have permission to smack me upside the head for not listening &(%$(&@$%(@&$%(@&$^%(@$
We could have DEF saved my old motor by switching springs even after the re-build. I have learned sooooooo much about springs the last few months that I've become an expert on them (or something). And if there's one thing I did learn it's that there's HUGE amounts of power to be had by simply having the correct set in your motor, you've been right all along and the time and effort You and Jim put into the springs is surly paying off now

AMOF for those having a hard time swalling the 600 HP Mags get ready cause there's a schitt load of them gonna be on the track in 06. Jim sent one of these "new generation" JDM Motors (like I have) to a customer last week, he installed it this past weekend, put some miles on it, and dyno'd it the other day with my tune (Jim sent him my identical tune since he has the identicle set up, Mag + 8lb lower) WAM 598 RWHP on someone elses Dyno, hehehehe...

And for the record mines going back to JDM in a month or so for another set of springs Jim has invested dam near 10K to R+D and bring to market. We should get it up to 620 (or more) by just changing the springs from 105LB to the new 125's

Charles dont have it handy but you can see what your talking about on some of these old Dyno's of mine
Look what happens to both the Tq and HP @ 4700 RPM


Even here off and on Nitrous (NOTICE THE N20 SPIKE ALL, hehehehe)
you can clearly see max HP was at only 4700 RPM


Same here

 

Now look at the new Motor with the 105lb springs





And again these ARE NOT my best #'s
My Folder and better Dyno Sheets have been mailed to me and I will DEF have it today or tommorrow, on those sheets you'll see max HP at 6000 RPM
with no dip off

 

Rob my graph drops off just like yours did at the same power level. But i was running Upgraded heads. Ive since then had the springs shimmed due to Charles's recomendation ,just dont have the new dyno results. I keep talking about it but i gotta get my lazy azz off to Sals. Im sure we'll then see another 600 hp mag out there.
Jason

 

Good results, you did say that was on Race Fuel Rob?
What rating is your fuel?

We have pump gas here which is 97 oct rating so that will be my road fuel.
You pay a bit extra for it though.

When I drop the fuel tank to install uprated pumps I will fit a drain plug.
To ensure all street fuel is out when I put in High Oct Race Fuel for 1/4s

 

Jason,
A lot of these ported and cam'ed heads have valve springs that are the same or only slightly stronger then the stock ones, at least the earlier heads were that way. To my knowledge JDM stage II heads were 80# and the stageIII were 95#. I understand the Patriot heads are 75#.

If you have stock cams you can shim CompCam's springs .090" and get 99# seat pressure. Other then that Endra-Tech has a spring that will fit the L that is 112# on the seat that can be shimmed for a little more. And then there are Jim's Big Daddy springs at 120#.

The thing I would like to point out is stock block L's can benefit a lot for increasing spring pressure as their VE is lower then the ported and cam'ed heads and therefore the differential pressure across the valve that is trying to keep the valve from closing is even higher. The tools I designed makes replacing the valve springs in the truck a whole lot easier.

Charles

 

For you to post those dyno sheets is totally misleading. You need to clarify your post by posting that list of all the new stuff you bought along with those springs. the springs alone didnt wake your motor up and make all the difference in the world, it was a combination of all your new parts, from the 9:1 motor that isnt innovative in anyway at all to your ported heads and new cams. your making more power because your flowing more air and your on that dyno. oh yeah and because you spent alot of money and run your mouth alot. please make sure that this time around you show Sal the common courtesy and post any and all negative things you find with your new found powerplant, no matter how small or insignifigant they may be.

AD

 

Is it finished yet? I know you were designing it.