WOT 428 power improvment sugjestions?

[NIsaacs]

I am looking for any small HP tuning tricks that all you FE engine builder/owners might have. Currently running a 1975 F-250 4x4 puller in the 6500 lb stock gas class. I think It was Barry that said it so well in one of the engine build threads. "It don't matter if it idles like crap and stumbles through the pits, if it makes power where it is working is what matters", true story!

I know you guys like details so here is a small rundown of the truck. I think I have the gear ratio, tire size and chassis dialed in. I am running 4.88 gears, 31" tires and a 2.72 low gear kit in the c-6 w/3k stahl. I really don't want to go any slower since speed/momentum is key. The last pull was 16 mph @ 5800 rpm. I would like to get that up to 17/18 mph and 6000/6200 rpm.

Engine started life in a '67 XL 428. I have built it twice over the years (30) and is currently 60 over (440 I think) about 10.5 compression, sorry I really don't have much tech specs on this part. I have a complete RPM top end kit installed, one piece at a time (more work but I wanted to see how it responded) because even thou I am a good mechanic I am not a good hotrod mechanic. My last addition is a Pertronics distributor set for 21* initial 37* total, I have not pulled it yet with this. The old oem duraspark was erratic as heck and I think a major problem. I used my 3k Huges stahl converter as my dyno  for this setting.

I was wondering if a 1" spacer might be good for 5 hp would a 2" or even 3" help? I have plenty of room in this truck. Also my headers have the one piece collector that necks down to 2.5". I run them open so would it help to cut the 2.5" off at the 3" size? I am also still running the factory PCV system. Is that an issue? I noticed that most of the dyno tests were done for street or some street/strip use, that won't apply here.

Thank you.

Nick 

[Drew Pojedinec]

You say you run the Edelbrock Performer RPM top end kit?
I've never had one, but the talk around here is that it isn't always the best choice.  Have you considered a custom cam from someone that can tailor it to your specific usage?

[NIsaacs]

PS: I really can't afford any more major engine mods due to extensive travel expenses. I pulled 15 times in 6 states this past season so my travel expense is significant. Just looking for small tuning tips that might help when inches count, I missed 2nd place by 18" at the last pull but that's okay because I was beat by 2 Fords, I managed to stay ahead of the Chevys, Lol.

Thank you,

Nick

[NIsaacs]

Thanks for the feed back Drew, I guess I was typing. I hear what you are saying about better choices however I didn't do my homework in time so I kinda have made my bed and need to sleep on it, see my PS above. Anything else you might add, thanks!

Nick

[machoneman]

By all means experiment with carb spacers and don't stop at only 1". Try one spacer and then add another to 'see' the difference. This may kill a tad of low end but, though not really familiar with your form of racing, methinks once you hit the pedal your climbing up the rpm range fast and holding it there. 

Header wise, yes, go to a 3" collector and if you can, you may want to experiment with a 3.5" collector. That and collector extensions about 2' long.  Then use a large yellow/white crayon and mark a thick and parallel line on the side of each extension. After a few runs, you'll see a burn mark as noted in the link's picture. Cut the extension off at the end of the burn make and you've optimized at least the overall collector length.

http://www.headersbyed.com/hc_cheapperfgains.htm

Cam wise, I'll guess the cam was degreed and installed 'straight up". If so and low end to get going isn't a big issue, you may retard the cam a few degrees (top end gain/low end loss) and see what happens. Lotsa work but pretty cheap with a multi-indexed camshaft gear set.

There is hp to be gained (or lost) based upon your fan type:

http://www.network54.com/Forum/215655/message/1066184641/Car+Craft+Cooling+Fan+Dyno+Test

The best would be electric fans followed by an OEM type standard duty (not HD) thermal clutch fan.

Because the truck is kinda' stationary when moving (unlike a drag or track car) you could for a few $ weld up a deeper oil pan
from two used factory pieces (and a longer pickup tube) to minimize splash and likely get a few more ponies. Most cars don't have the room but I'll bet you do.  It's possible though this move may not gain any free hp since the oil isn't piling up in the back like it would in a high G drag car.

One other thing to try.....racing gas. A dose of better-than-pump-gas in the 108-112 range that is highly oxygenated should provide a few more hp. Btw, one must play with total timing here a bit to see any gain. The goal here isn't to break your budget but to point to another issue, your compression ratio. Likely, a gain in power with racing fuel would indicate, if you can afford the gas, a need for more c/r. Sounds like we'd all know this already but even small C/R increases (say milled heads) from your current 10.5 to 1 to a higher number would outstrip the smaller gains IMO from spacers, larger collectors and optimized collector lengths.

     

[price5113]

If your running open headers, ditch the PCV and consider a "Crank EVAC" system. Also might consider some "thinner" oil when you need to do your oil change...............

[KMcCullah]

I would definitely play with carb spacers. Get a copy of Jays book if you don't have one already. It has a few carb spacer dyno results. It also has dyno results for different headers. The Dynomax truck headers were affordable and made the most HP as I recall. There now I've got my recommended daily allowance of unpaid endorsements out of the way. 

I don't know much about sled pulling but have tried it with my truck. It was a damn good time but only happens a few times a year around where I live. Not enough for me to justify building a truck for it.
 http://fepower.net/simplemachinesforum/index.php?topic=1884.msg16892#msg16892

Do your class rules mandate an automatic trans? Or do you just prefer the C6? I've read where a lot of drag race guys have ditched their C6 in favor of a Liberty or Jereco manual tranny and picked up a few tenths. I think the C6 has quite a bit of parasitic loss internally that eats HP. Maybe a few of the drag racing guys around here can elaborate some more on this.

The Ed RPM kit you have has a hydraulic flat tappet cam yes? There's a lot of HP, torque and RPM potential being left on the table with a hyd. flat tappet. Upgrading to a solid flat tappet could be done on the cheap and would let you get more aggressive with lobe profiles and would let you rev some more. Of course valve springs would have to be swapped also. A roller cam would be better yet but now were talking a few clams to get there.

[machoneman]

yes, sadly, the C-6 has the highest hp loss of all trannys:

http://www.460ford.com/forum/archive/index.php/t-118570.html

And yes, a direct drive (stick) tranny would transmit far more hp to the driveline than any other tranny.  Btw, this means a 4 or 5 speed tranny. A Lenco actually does suck up a lot of hp (in exchange for never missing a shift!) but I don't know how much compared to a C-4, 'Glide or C-6.

[ScotiaFE]

Interestingly Jay tested the crap out of the Edelbrock Hyd cam. p/n 7106 in his book.
Held it's own in the 428 CJ 425 Hp.
Certainly a bigger cam will make more power, but it's not like he has an RV stick in there if he has the big Ed hyd.
More carb info?
Port matching?
I'm surprised the Duraspark was acting up, normally a very reliable dizzy.

[NIsaacs]

The RPM cam seems to like a lot of initial.

I do use 110 race gas mixed with pump premium at about 100 mixture. Should I go more?

Nick

[Drew Pojedinec]

I'd be interested in putting my full roller c6 on a wheel dyno compared to a standard build c6.
Just spinning the rotating mass via the output shaft vs a normal build it is a HUGE difference.

I always felt that 50-60hp loss for a c6 is bs....  Every time I've ever seen any data about it, it references the exact same Carcraft article, that alone makes me suspect.  Yeah there is a heavier rotating mass to get moving, but once moving I don't see how it would hurt hp THAT much.  but I might be wrong.

From the 460 forum, Frank Merkl states:
"just checked an standard C6 with the forward and low clutches applied with air, took 38 ftlbs to turn -a rollerized C6 11 ftlbs !!! that's a BIG difference"

[My427stang]

1 - Make sure you are getting full throttle and that the secondaries don't bind when moved by hand (engine off)
2 - I'd bump it up to 38 total, maybe even 40 if you have good fuel.
3 - See what you can do for a fuel line, at best its 3/8 out of the tank, you could use more for that RPM/load.  My 71 F100 has a 5/16 feed, not sure what yours has, but it's too little
4 - Your PCV doesn't do anything at WOT, just make sure you have 2 good breathers or as someone said a pan evac

You may not be able to get those revs without adding valve spring pressure.
Any chance you checked open and closed pressure before putting it together?

What are you running for headers?
Any header extensions after the collector? 
Any way you could shut it down right after the pull and tow it to the pits to read the plugs?

[machoneman]

I'd be interested in putting my full roller c6 on a wheel dyno compared to a standard build c6.
Just spinning the rotating mass via the output shaft vs a normal build it is a HUGE difference.

I always felt that 50-60hp loss for a c6 is bs....  Every time I've ever seen any data about it, it references the exact same Carcraft article, that alone makes me suspect.  Yeah there is a heavier rotating mass to get moving, but once moving I don't see how it would hurt hp THAT much.  but I might be wrong.

From the 460 forum, Frank Merkl states:
"just checked an standard C6 with the forward and low clutches applied with air, took 38 ftlbs to turn -a rollerized C6 11 ftlbs !!! that's a BIG difference"

Agree the data is very limited and that rollerized trannys do help, a lot, to minimize hp loss. Yet, that old data is the only source, apparently, available for comparison. The PG racers do claim they have the best low drag tranny and looking at the parts spun up between a PG and almost all other 3-speed auto trannies do show a much lighter rotating mass. The C-4 racers also have a big advantage over the C-6 unit. Do remember a racer (YellowBullet Forum?) who actually did swap a worked C-4 over a worked C-6 and IIRC he did pickup a about 2/10's in his drag car so a lighter mass does reduce hp loss.

More racer results here:

http://www.network54.com/Forum/85220/thread/1099787240/C6+Vs+Powerglide+test+results---

Still, I do wish we had more dyno data to make said comparisons! 

[NIsaacs]

Kevin, thanks for the pulling link, I read the thread and watched the videos, thanks for sharing. That class was too heavy for your trucks 5100 lbs, you would have won if the class max weight was 5200. That dang sled pulls hard, huh!?

I am running my factory water pump, fan and alt, however I run with the belt real loose. It keeps the trucks water temp under control no problem but slips big time when I get off idle. I read the fan article in the link and kinda like the tranny hp loss, I think 45hp is a bit much. I wonder if all the testing was done with an open thermostat? If it was closed on some of the testing you would get goofy results. I always figured a water pump with a closed thermostat and high rpm would take more power than a fan.

"Thinner oil" any recommendations? I use 10/40, maybe 10/30? Will the light weigh oil stand up to the severe use the bearings get? I do warm up my engine before every pull and try to get about 160 water temp. I still have the stock oil pump drive so I don't like revving a cold engine.

When I first installed the carb I checked for binding and had to loosen the nuts and open the throttle wide open and then snug it down. The clearance on the dual plane is barely enough. It is set for WOT, I had a helper hold the throttle pedal down while I adjusted the linkage. I have 3/8 line all the way, is that enough? I am running the red holly pump mounted on the frame under the tank.

I did not check the valve springs at all just bolted them on. With a small sled it will pull 7,000 rpm no problem but I doubt they would work for a different cam. The headers are Hooker with the one piece collector that necks down to 2.5 for the exhaust pipe to attach. I think I will cut them back to the 3" size. I did have to slot the bolt holes for the raised port of the ED's. I don't know if after you idle during the unhook and drive off the track if I could save the spark plug color by towing it from there to the pits, but that's a possibility. You do have to leave the track under your own power, no towing there.

Thanks again,

Nick

[lovehamr]

428, hyd. flat tappet, dual plane and It'll pull 7000rpm?! 

Steve