Ok, I got lucky and found a link on the Stang.net forum to a free download of the Desktop Dyno 2000 program. The download even included alot of cam and head parameters which are essential to even play with the program. The programs head files folder didn't have the flow numbers for the Topline heads I've got coming, but no biggie, I just plugged em in.

I was thinking that I might go for the 35-518-8 Comp. cam, but after playing with the Desktop Dyno man I think I might have to resist my normal urges to pick as big of a cam as I think I can get away with for that nice idle. I am continuely reminding myself this 408 is going in my heavy daily driver Bronco, not a street/strip terror. I plugged in the XE 258 HR 35-510-8 cam and wow my 408 should be a serious NA torque monster. I had not read about the XE 258 HR cam at all so I was shocked when I plugged it in and with the head flow numbers from Topline's website (which are apparently very accurate according to independent testing) and 9.75 on the compression. Holly smokes, Desktop Dyno says 482 HP at 5500 rpm and 546 ft lb's of torque at 4000 rpm. The program starts at 2000 rpm (wish it started a bit lower) and its saying my 408 should have even 205 HP and 538 ft lb's of torque starting at 2000 rpm. The program needs very specific info with regards to the head flow numbers and cam specs. However, it gets really generalized with the intake and exhaust selections. On the exhaust selection I just selected the small tube headers with mufflers as so far the headers it looks like I'll be getting will be the BBK 1 5/8". Which I've been told will be small for a 408. I'm hopeing it won't hold her back to bad.

All the engine/parts shops I've talked to are very used to thinking of a 408 buildups as being for a Mustang, so they are in the habit of recomending parts accordingly. Such as 1 3/4" headers and 215cc + heads. I utilized restraint and have the Topline 200cc heads on their way. These heads still outflow AFR 185's that are very popular. The iron Toplines I'm getting saved me over $520 as compared to AFR's ($780. total to my door with SS undercut stem swirl polished 2.055/1.60 valves, springs good for .600" lift).

The D.D. program is also alittle iffy on the intake selection. It just gives like single plane, dual plane, tunedport or sequential injection, and tunnel ram (I think that was all the options). Then you just plug in what cfm for either a carb or throttle body (I plugged in an 800cfm since if she was gonna be carbed I'd probably have a 800cfm Quadrajunk or Thermobog).

I am taking the numbers from this program with more than one grain of salt, actually a salt shaker. I have however come across quite a few posts on the net with people stating that this program with regards to naturally aspirated V8's is very accurate, many of whom have plugged in the specs for engines that they have had on a real engine dyno. I also plugged in numbers for a very nice 340 I had years back and this program pegged it right on the money. It was kind of amazing actually, peak HP right at the rpm range I'd feal the power peak at and pull to.

So anyways I'm gonna keep playing with this program a bit, but I may have found the perfect cam (in reality). I would have never considered a cam with this little of duration and was really leaning towards more lift also. This program may have just made a huge difference in the outcome I will hopefully experience for real in a few weeks. Can't wait, I've never rebuilt a choked V8 before so it should be a huge difference basically doubling the power output by freeing things up and utilizing current technology. The Desktop Dyno program really shows how much its all in the heads and cam.

 

wow, those are some huge #'s for a cam designed for a stock to near stock 5.0...

Did you run the #'s on the 35-518-8 and your combination, I would be very curious as to the results on that cam with your setup. Run the numbers on the 518 and let us know what your HP/TQ figures come up to.

 

Ya, its making me skeptical. The intake choices and the exhaust choices available in the program leave something to be desired. You'd think at least on the exhaust they would have actually given primary header tube diameters to pick. Oh well.

OK, on the 35-518-8 it says 187 HP and 492 TQ at 2000rpm, climbing to a peak of 501 hp at 6000rpm, and on the TQ it peaks 525 at 4000.

I wonder if I should be picking a different intake selection in the program, like instead of the tunedport (wasn't sure), maybe I should pick the sequential-fire injection.

Ok, if I change to the sequential-fire inj. the numbers are:

For the 35-510-8 at 2000rpm its 189HP/496TQ, climbing to a peak of 521HP at 6000, and the TQ climbs to 556 from 3500 to 4000rpm.

Still with the sequential-fire inj. but back to the 35-518-8 it claims 174HP/457TQ at 2000rpm, climbing to a peak of 545HP at 6500rpm and the torque peaks at 541 spanning from 4000 to 4500.

Even though I had read quite a few discussions of people claiming this program could be very accurate and It seemed right on the money when I plugged in the specs for the 340 Duster I once owned, well I'm definetly questioning how high the numbers get. I don't know if I should be, but I am.
The one thing I feal I can more than likely rely on the program for is with regards to where the cams seem to like to peak at. Which still has me leaning towards the 510 cam at least as of current. I'll play with the different intakes some more just to see how the cams act. Interestingly the little bit I've plugged in the single plane carb type intake the numbers really jump up. I hope my engine likes my Topline heads as well as this dyno program seems to.

Hey, if you spot my car/Lightning intake questions in my other post, feal free to sound in with any input, thanks.

 

Thats interesting how different the #'s are on those two. I would have thought the 518 would have came in higher than that. Is that with the compensation for the stroker engine size? I would have also thought the rpms would have been much lower on those cams with the stroker. You might want to try to get ahold of ratsmoker and have hom run your combo up and see what he comes up with, his version might have more parameters that he can plug in there. Let us know what you come up with!

 

Thats a good idea to do some cross checking.

Basically, the only parameter I don't know for sure to pick is the intake. Kind of funny that the program does not get alot more specific there. I also sure does affect the results, because as I mentioned man if I plug in the single plane intake, wow it acts like its not far off from being a 7000rpm buildup with 600 hp with the 518 cam. The program is very lacking in several areas. Doesn't even let me pick deck height and rod length. I imagine its doing stock deck height but, rod length?

If I had to pick right now man I think it might be that 510, but I'll play some more cause we don't want to give up anything, ya know!

 

When we ran the #'s for the 518 cam in my 408 the peak HP came in at 5500 RPM and peak TQ was at 4000 rpm,and both HP and TQ were estimated to be much lower than that, so it makes me question the validity of the program you have. It just seems as though the 518 should be making considerably more HP/TQ than the 510, given it is a larger cam and you do have more displacement, so I would be interested in what someone else comes up with on comparing the two. You might want to run up the XE 266 HR too, its the cam in between the two.

If you do make that much HP/TQ, your going to be looking at a large fuel system to feed that motor. So be sure to adjust the sizes of your injectors, fuel pump(s), fuel rails and regulator accordingly.

 

I agree to some extent. I mean I do question how high the numbers are.

With regards to the 518 not being much better than the 510 on the numbers. Well the only way I can rationalize it would be if I think about an article I read about the relationship between the cam lift and head flow. In this article it pointed out that it has little to no effect to run a cam with .700" lift if the heads stop flowing at .500". Now my heads are supposed to peak at .700" according to Toplines numbers, but the difference from .500" to .700" is only another 10 cfm gained (approx) on the intake and exhaust. I'm kind of just speculating ofcourse, but that may explain it. I don't know how much more power another 10 cfm equates to, but it has me thinking that may verywell be the reason the 518 does not have much on the 510 as the difference in another .020" lift just might not be much more. Although you'd think the duration increase would do more than just shift the power range.

Just out of curiousity, did you get a chance to run your engine without the supercharger???? I couldn't remember what you'd said in other posts. And when you guys ran your engine specs in the Desktop Dyno were the numbers for it being naturally aspirated???? Because I know SC's add alot of TQ, not sure if it could lower the power range though, maybe.

If you did, well what did it run like power range wise???? Did it seem to peak at the same rpms as the Desktop Dyno had said it would????

I've personally got the fealing my desktop dyno is somehow/for some reason, giving me an extra 50-75HP and Ft lbs of TQ.

The 510 cam is considered to be the torque king of cams according to what I've been reading. I may have only one way to find out and thats to try it.

 

What are your CFM #'s at .500 on the toplines? I would think that given the addtional duration and heads that have good flow #'s that you shuld be getting considerably higher numbers on the HP side with the 518, not nessisarily on the TQ.

No, I never ran my 408 without the SC. The rear wheel estimate on it with 12 lbs of boost was 600-650 HP.

Where are you getting the information regarding the 510 cam, and has any of them ran it in a stroker 408?

It sounds like the one to go with (the 510) if the information you have been given is correct.

You might want to verify it with a different tech at Comp to be sure. I just dont know if its enough cam for a 408 since it is listed as a cam for only a stock 5.0. The operating power range drops considerably with larger displacement engines for these cams, along with the output that it can provide.

 

Very good point.

276/193 cfm at .500"

I actually just stumbled on the 510 using my Desktop Dyno. The download I found happened to include a cam folder and head folder (program would have been almost useless without it). Both of which include almost all of the popular head and cam options/specs. So I was playing with the program and I had plugged in the 518 and was curious what the 408 would do if I picked smaller cams. That was how I came upon the 510. From there I just did a bunch of searching on the net. I don't think I came across anyone specifically using it in the 393 or 408's (that I rememeber). Mainly 351's, 347's and 302's. Just alot of people talking about having tried E'brock Performer cams and other cams in that general area and how they'd been dissapointed with these cams. So based on what they had heard they gave the 510 a try and they all seemed to love it and talk about how much better it was. Also came across alot of people running their engine specs with the 510 cam in the Desktop Dyno and then telling them how much more HP/TQ it said they would make and then they did.

I've been having abit of disscussion with a guy from Ford Fuelinjection, as I'm trying to figure out how to go about the Mass Air conversion. And this guy is telling me how all the kits available (except his ofcourse) are junk. So anyways he's telling me unless I have $2000. and 3mos due to the wiring work, to forget about the Mass Air conversion and get a Lightning SD computer and a Tweecer. And he's telling me to run a 35-255-5 cam as its the biggest that will work with the SD. I looked up the specs on that cam and I can't believe he's telling me to run it in a 408. Its like 198 at .050 on the intake duration and well under .500" lift. Hell I wouldn't want to run that small of a cam in a 302. I was just going to get the FMS Mass Air conversion kit and I was thinking the Tweecer right off the bat and maybe do a custom harness later on to get rid of the overlay harness the kit has. But this dude has shot down the FMS and Pro-M kits to such a degree at this point that I now need alot more input from other people regarding the conversion to know what the hell to do. I want to do the conversion before I even fire this baby up for the first time. Just don't know what to do at this point with the fuel management. Maybe I should look for a Lightning SD computer and keep it simple up front and worry about the conversion later. But man there is no way I'm running the cam this guys telling me to run. I just can't see it at this point. Hell my heads that I am expecting any minute are coming setup with springs for a roller cam up to .600" lift. Not a flat tappet with .450 to .475 lift. This dude sounds like he knows the computer stuff, but he's got me all screwed up on what to do. I need to talk to some other people about this conversion, cuss I know there's usually more than one way to do things. Not according to this dude though. The one good thing is that the way I am when I finally get the Bronco back rolling I'll be pretty educated for that future Mustang buildup.

Sorry to ramble and raint and thanks for your help and input.

Peice!

 

I would do some more searches for some others out there that have did the MAS conversion. I dont know where your located, but you might try calling some shops like Apex Motorsports in Santa Clara, CA or Mustang Ranch, also in Santa Clara, or try Byron at RACE Systems to try and get some info regarding the FMS and Pro M kits, tht just doesent sound right that those two would be junk. I agree that your going to want to have it all set up with those heads and roller cam.

Anyhow, back to your cam issue. The numbers that Ratsmoker came up with for me running the 518 cam in the 408 NA was around 430 HP and 485 TQ, HP peak at 5500 and torque around 4400. That was running my twisted wedge heads and the Edelbrock truck intake, both have stage 3 full port. The full port TW's flowed on the bench at 289/193 @ .500. So, I'm still scratchin my head tryin to figure out how the little510 cam could be higher, we ran a pile of different cams both large and small through the program and dident come up with any HP/TQ numbers that high, or the RPM being that high either.

Let us know what you come up with!

 

Guys, you need to set your lifter type properly. Do NOT use the HR lifter setting unless you are using a very exotic race cam. For a standard street HR cam use the SOLID lifter selection. The book that goes along with DD explains all of this. You need the book to use the DD program properly. All of those "settings" are not as they seem to be.

 

Just got the Toplines via UPS, they look great. Lots of meat for porting aswell, not that I need it for this application.

I just found out about the National Lightning Owners Assoc. website. I think I will be able to get the question of whether to do the Mass Air conversion answered over there. Likewise how to go about it.

Ok, earlier I called the Comp. Cams tech line again and thank god I got somebody different from my call the other day. I told the guy what I and about needing to pass emissions testing and wanting as much power as I could get away with and all the other details we've disscussed. The guy said he'd recomend the 510 grind and should have the best low end and power from approx idle to 5300-5500 rpm, he said if I wanted to shift it up just a touch to use the 514 (still with stock convertor), and if I really wanted to push the emissions issue and didn't mind running a 2500 rpm convertor, to pick the 518. Sounds good to me. Although I am alittle surprised that a 224/232 duration cam in a 408ci even really needs a 2500 convertor. I guess with it being in a heavy truck and all, maybe that would be a good match up.

I did mention to the Comp. Cams tech guy the DT Dyno results I had. His opinion for what its worth was that with the 510 I'd probably be around 430 hp maybe more and that the torque numbers could possibly surpass 500 ft lb's. I mentioned the DT Dyno saying close to 550 ft lb's and he said ya its possible.

So, I don't know really what to think at this point. I'd sure like to know, but I'll probably have to put her on a chassis dyno to get a realistic idea. Don't know that I'd bother unless it was for tuning purposes.

So I'm going to give it some thought I probably in reality have another week or so before I need to order the cam so for now its between the stay conservitive 510, or the 514, or hey ya wanta race little ricer 518. Actually I was taking ricers with the stock engine with maybe 225-250 HP.

If you'd like, let me know and I'll give every detail I plugged into the DT Dyno 2000. Seems like my version might be a liar and tell you what you want to hear.

Now I'm gonna go see what these Lightning guys have to say. I'll let you know.

 

I'll see if it will let me change the lifter type I had just been selecting the cam from a folder and playing with the intakes.

That sounds like it could explain it though.

I'll let you guys know.

 

You the man Torque1st.

I changed the lifter type to solid flat tappet and that definetly knocked some wind out of the 408's sails.

I don't know why I'm happy about that.......um, except that I guess I wish this thing could be more accurate so I could see more realistic results.

Now if I just new for sure what intake to choose.

Ok, if I stick with Sequential Fuel Inj. intake (which is what the ford mass air is) Tuned Port selection lowers power range and peak output, but there again brings it on sooner.

Ok, 510 cam starts at 181hp/476tq at 2000rpm, climbs to 474hp at 5500, 530tq at 3500.

518 starts at 168/440, and climbs to 514hp at 6000, and 518tq at 4000. Lots more peek hp, but.......

Wish I could copy/paste the curves for ya, but it won't let me right click.

Something in this engine according to the dyno, I suspect intake and possibly still the small headers (I'll experiment more and see what it likes), does not like more lift. For example, both of these cam files were saying .530/.540 for the 510 and .550/.560 for the 518. And I noticed from the internet and confirmed with Comp. the real numbers on these cams are .533/.544 and .555/.565. Interestingly, when I correct this small error and put that little bit more lift in, both cams loose power a touch. This thing is finicky. Makes me want to play with it more though.

 

Later I'll try knocking some cfm out of the heads at all the incremental lifts as they probably will be touch less in reality, and will see what that does to it.

I wonder if this thing is taking some kind of port velocity calculation into account?