12's to 11's

You can gain alot with somewhat small changes!
I started out going 12.98 with my truck 3 years ago. It's going 11.70's now with 11.60's coming soon.
The 3 major changes were cam,converter, and gear.
I have a tci street fighter (elcheapo) converter. Solid flat tappet cam, dur @ .050 254/261, lift .615/.635 @ 1.73 ratio. I have 1.8 ratio rockers on the exhaust so lift is a little more. 9" rear with 4.10 gears on 29.5x10.50 hoosier slicks.

I started out with 9 1/2" converter that never locked up the entire 1/4 mile. Hydraulic cam with .544/.544 lift and 3.50 gears.
The truck has a 472ci engine
850 dbl pumper
stealth 8012
dove's with 2.19/1.76 valves, home ported
2" home built headers

Keep at it and take note of the comments here. The wealth of knowledge on this forum is priceless!

mike

Cheers Mike, your results have pretty much proven what Dfree suggested in the earlier posts.Is you cam custom ground or an off the shelf item? If off the shelf what brand is it? Also what are your jet sizes in your double pumper?
What future plans do you have for the truck? Going from high 12s to high 11s is good progress, you must be pretty happy with that, keep up the good work and thanks for your post.

f250mike wrote:You can gain alot with somewhat small changes!
I started out going 12.98 with my truck 3 years ago. It's going 11.70's now with 11.60's coming soon.
The 3 major changes were cam,converter, and gear.
I have a tci street fighter (elcheapo) converter. Solid flat tappet cam, dur @ .050 254/261, lift .615/.635 @ 1.73 ratio. I have 1.8 ratio rockers on the exhaust so lift is a little more. 9" rear with 4.10 gears on 29.5x10.50 hoosier slicks.

I started out with 9 1/2" converter that never locked up the entire 1/4 mile. Hydraulic cam with .544/.544 lift and 3.50 gears.
The truck has a 472ci engine
850 dbl pumper
stealth 8012
dove's with 2.19/1.76 valves, home ported
2" home built headers

Keep at it and take note of the comments here. The wealth of knowledge on this forum is priceless!

mike

i did about the same thing changing cam, intake, cnverter & gear made up 2 second 13.20 to 11.50's my best change was to go overdrive trans 70mph with a 3.89 gear is 2300 rpm's

51Custom wrote:Cheers Mike, your results have pretty much proven what Dfree suggested in the earlier posts.Is you cam custom ground or an off the shelf item? If off the shelf what brand is it? Also what are your jet sizes in your double pumper?
What future plans do you have for the truck? Going from high 12s to high 11s is good progress, you must be pretty happy with that, keep up the good work and thanks for your post.

The cam is a custom Grind from Delta Cams.
Jet sizes are 86 front, 94 rear with no power valve.
I'm not sure of future plans for the truck. We might build a 96 ext cab ranger to run the 11.00 index.
If the ranger build doesn't happen then I want a new race converter and a single plane intake with 1050 carb.

Dfree if your still reading this topic, I posted my advertised duration figures , and I've realised everyone is using the duration at 50" figures. Mine are 252 and 256 at 50", does that change anything as far as what you recommend? Also everyone has over 600 lift on their cams, quite a bit more than mine. Whatta ya reckon?

51Custom wrote:Dfree if your still reading this topic, I posted my advertised duration figures , and I've realised everyone is using the duration at 50" figures. Mine are 252 and 256 at 50", does that change anything as far as what you recommend? Also everyone has over 600 lift on their cams, quite a bit more than mine. Whatta ya reckon?

The cams to big for the convertor, gearing your running and weight. You need to get something custom ground.

also a problem your going to have is to much compression for a typical shelf small cam (it will detonate on pump gas)

If you want to keep that cam your going to need alot looser convertor and more gear to go faster. or give it a small hit of NO2, something in the 100-125hp range, with some race gas for the enrichment.

ok got it,thanks. talked to the convertor guy, will change the stall, diff ratio and try a bigger carb. nitrous isnt economical, $200 per bottle. will kep you posted.

51Custom wrote:ok got it,thanks. talked to the convertor guy, will change the stall, diff ratio and try a bigger carb. nitrous isnt economical, $200 per bottle. will kep you posted.

The NO2 is a lot cheaper here.......

f250mike wrote:You can gain alot with somewhat small changes!
I started out going 12.98 with my truck 3 years ago. It's going 11.70's now with 11.60's coming soon.
The 3 major changes were cam,converter, and gear.
I have a tci street fighter (elcheapo) converter. Solid flat tappet cam, dur @ .050 254/261, lift .615/.635 @ 1.73 ratio. I have 1.8 ratio rockers on the exhaust so lift is a little more. 9" rear with 4.10 gears on 29.5x10.50 hoosier slicks.

I started out with 9 1/2" converter that never locked up the entire 1/4 mile. Hydraulic cam with .544/.544 lift and 3.50 gears.
The truck has a 472ci engine
850 dbl pumper
stealth 8012
dove's with 2.19/1.76 valves, home ported
2" home built headers

Keep at it and take note of the comments here. The wealth of knowledge on this forum is priceless!

mike

Can you give me more information on using a different ratio rocker on the exhaust? i guess it would have changed your pushrod length, any idea how much more lift you ended up with? And how did it affect your valvetrain geometry?

51 have went from the 8's to 6.70's in the 1/8 mile with dove-c heads 1st build was a pump gas engine with stock crank,rods,and pistons,cam xe274h .565 lift comp cams hydrolic cam ran mid 8's.Rebuilt the engine put flat top pistons in and had a custom cam .642 .649 lift built for it 7.80s changed carb to a 1050 from a 850 went 7.27 then changed my convertor ran 7.10s went to alky it ran 6.70s in the 1/8.My dove head have the stock size valves 2.08 intake 1.65 exhaust valves intake port matched to a g429 frpp intake it is the same as the eddy victor the exhaust port have been ported and bowl bend.I have now changed to some a429 frpp heads not sure how it will run with them yet haven't had time to go to the track with it.I believe you have enough heads for a bigger carb it want hurt to try it.Here is my build on mine

https://www.429-460.com/t85-jim-s-little-460-and-2000-ranger

The intake and exhaust pushrods are different length.
If my math is correct the lift on the exhaust is .660 with the 1.8 rockers-vs-.635 with the 1.73 ratio.
I can't answer what differences it makes going to the 1.8 ratio from 1.73 with this cam. We already had the 1.8's on the exhaust when this cam was ground for me.
A few years ago I mud raced in a vacuum rules class and I had room for a little more cam. The increased rocker ratio seemed to be the cheapest and easiest way to gain a couple hp with what I had. Not really sure if it made much change.
Maybe one of the engine builders here will let us know what differeces can be expected with the 1.73 to 1.8 rocker swap.

51Custom wrote:ok got it,thanks. talked to the convertor guy, will change the stall, diff ratio and try a bigger carb. nitrous isnt economical, $200 per bottle. will kep you posted.

Thanks for the information F250mike and 69F100, very cool build 69F100 and well documented with lots of pics. Another thing, had a couple of different opinions about how to use your high stall for drag racing. The dude who built my convertor reckons its best to sit at the lights at idle then nail it when you ready to go and the convertor will flash up to its stall speed and your gone. Other guys get some revs on close to their stall speed, rather than letting it idle, then nail it on the green light. whatta you guys do and why?

I don't have a trans brake so foot brake is all I have, I have tried coming up on the stall but I get my best 60' time leaving off idle.I have a 4500 in mine all I can get up to is about 2200 before it pushes me out of the lights leaving that way my 50' time is 1.49 to 1.52.Leaving off Idle 60' time is 1.42 I have a recall tach as soon as I hit the gas it jumps to 4500.My truck idles at 1000 rpms it will idle lower to 800 but sometimes when i nail it will stumble alittle at 800 but at 1000 rpms it don't.Some say they get better 60' times by coming up on the convertor but mine does better from idle.If I was you make a couple pass coming up on it then a couple leaving off idle and see what your 60' times look like to see what yours like best.

Jim

I have a Frank Merkl trans brake.
The old truck needs all the help it can get off the line
We index race, so the first off the line has the advantage at the big end.
The guys in my class foot braking generally have a slower reaction time unless they deep stage.
If I know they foot brake, I try to stage first to keep them from deep staging.

Well i got some good news and some bad news. Took the sled to an annual 1/8th mile drags, its a public street in an industrial area which is closed for the event. I loaned some 4.5:1 diff gears off a mate, put some Hoosier quicktimes on and tramp bars. Only managed one pass, the second burnout the rear driveshaft yoke let go, broke the driveshaft in half and cracked the transmission case! But on the first pass The car did an 8.003 which is considerably better than the previous best of 8.197. But shit drag racing is hard on ya gear

51Custom wrote:Well i got some good news and some bad news. Took the sled to an annual 1/8th mile drags, its a public street in an industrial area which is closed for the event. I loaned some 4.5:1 diff gears off a mate, put some Hoosier quicktimes on and tramp bars. Only managed one pass, the second burnout the rear driveshaft yoke let go, broke the driveshaft in half and cracked the transmission case! But on the first pass The car did an 8.003 which is considerably better than the previous best of 8.197. But shit drag racing is hard on ya gear

There you go. You make some changes that are definately in the right direction and BANG! you find the weak link. And you look like a pushing your broke junk out of the way. Been there, done that. But hey, you learned the thing leaves much harder with that setup. And now your transmission is out (at least partly out) so you can upgrade the converter.

I've grenaded 9"s, bent leaf spring mounts causing universal joints to let go, blown head gaskets, melted spark plugs and aluminum heads, blown up transmissions, converters, had spectacular nitrous pops... It's all part of the fun.

okay, redid the Nostalgia drags last Sunday and managed an 11.9 @ 115 mph, 7000 rpm over the finish line. Over the winter I rebuilt the short block and had a custom made cam ground up which gave me around .30 more lift. They didnt really alter the duration that much though. I used the same 2800 stall and couldn't get my diff sorted in time so used my mates 4.56:1 ratio diff for this event.This is probably why I was doing 7000 over the finish line. My question is this, is this many revs too much for the big block Ford bearing in mind it's not a race motor but a street car? Using a stock 2 bolt block, stock crank, H beam rods, forged Ross pistons, bottom end stud kit and windage tray. Stock oil pump as well