OK guys..
heres what I want to do..(one day ;) )
My best run with my car has been a 12.99
my best MPH was 103.4
best 60 ft. 1.83 (drag radials)
It normally runs 13.20's up to 13.30's with 2.05 or so 60 fts.
I recently swapped to an RPM intake-no other changes..previously ran a Performer.
Now,I haven't been back to the track yet,and I usually make it a point to go back when something in the combo changes..chances are though,I will be going back in late summer or early fall and have not only the RPM,but 3.31's installed as well.
In reality,I'm expecting maybe 1.5-2 MPH increase from the gear and intake swap (thoughts?)
That will put me in the 105 or so MPH (thoughts?)
..and,I hoping I won't need a 1.83 60 ft. to run a 12.99 again with 3.31's
Maybe it'll only take a 1.90-1.95 60 ft. to a run a 12.99 with the gears.
With a 60 ft. in the low 1.8X/or a 1.79,I'd like to guess that maybe a 12.75 is there.
Tires are Hoosier QT DOT Pros 15x9.5x26
Stock F41 suspension.
Again,I previously cut a best of a 1.83 before the gear/intake swap..with 2.73's
Convertor is a B&M 2400 Holeshot..
So,
say I stepped up to tight 10" convertor that flashes to 3500,how much would my 60 ft. be reduced,and what would it possibly run?
With that in mind,is a 12.60 maybe possible?
Again,that would be a best (weather/traction)
And at last,without changing anything else,except a cam,what cam would be needed to put out an occasional 11.9X ET,but more likely a 12 second car most of the time (12.20-12.30's or so,depending on weather/traction)
I'm guessing a high 1.6X or very low 1.7X to get in to the 11.9X's..thoughts?
I'm sure there is a solid roller or flat tappet solid that could do it,and have reasonable idle quality,etc.
I'm assuming a hydraulic flat tappet is out of the question,due to the fact using 3.31's/small valves.
This is a 10.5 to 1 (.100 domes and decked block) 454,#215 heads,stock 2.06/1.72 valves,RPM intake,3.31's,TH400 exc..exhaust is small tube headers/2.5" pipes
Current cam is the UD 280/288
Don't want to change the valve size or the gear.
I realize that with the appropriate cam, 3.73's and bigger valves,it would probably run mid/ high 11's all the time,but thats not what I want.IMHO,everything is an equalizer,so if you reverse engineer it,what would it take for my car to run mid 11's and then detune it run run high 11's/low 12's with 3.31's and the small valves ;)
I like to be able to drive my car,so the 3.31's are essential,no overdrives either.TH400's are cheap and strong graemlins/thumbsup.gif
..and I'm guessing a 3" exhaust would help.

Chris,
For as much street driving as you do, i would not suggest a solid roller.

My suggestion is a hydraulic or solid flat tappet cam.
I'll take a look through a few manufacturers lobe catalogs and get back with a suggestion.

Imho, would think you will really like the 3.31 gears, I know I do..

And futher, I would think that just some bowl and port clean up work on your heads even with the small valves would really wake your motor up if it hasn't been done to it already??

One last point is, are you driving your own car at the track like you stole it???

pdq67

Chris ,I went from 13.69 @ 98.7mph using a 11" 2800rpm about 2000 stall converter to 13.2 @ 103.8mph using a 10" 3500rpm converter with about 2900 stall and went from 2.0 -60ft to 1.86 60ft ,i
My car got a 3000rpm - 6500rpm cam and I needed the motor to go from the stage line at more rpms so the first converter was not the right one ,it was staring to go of the line hard at 3000rpm so there was the 60.ft improvement went the little bigger converter was in .
I know you will go 12.3, 12.0 e/t just with lower ring pinion and converter .
That car is amazing with that 2.73 graemlins/hurray.gif

Chris,

I had a buddy that ran a home grown BStock/A way back when, pretty sure that was the class for a 454/360 car . Reminds me of your car now. Difference was 4.10's and a cheater cam, that we now know was around 310 - 320 duration, but low lift. If I remember right, he ran 12.10's to 11.90's? [Been a long time, but I do remember the car was white]. The one thing that I do know, contrary to what most want to believe, the closed chamber BBC heads favor duration over lift, especially if you have compression. I would wager that an increase in intake duration in the 290 - 300 range ( talking hydraulic flat tappet ) would increase your MPH substantially. Lift over .550 is overkill for the heads - really, anything over .510-.520, the excess lift only serves a purpose of getting more duration at .400 - .500 where these heads work best.

Call me old fashioned, but I like bigger cams in a rat motor. Did you look into something like the Lunati 0026 [293/302, 232/239, .540.550 on 110LSA w/ 104 ICL] as a starting point and then go up. Very similiar to UD288/296 with a little milder ramp.

Glad to see you did the 3.31's, but there's no way that car hooks now! By the way, guess what dummy had 32lbs of air in the street radials!

Joe,I happen to have a Lunati 231/239 @ .050 .549/.558 110 LSA..I forget the advertised.
3.31's are not in yet,but should be over the next few weeks.
Interesting info on the closed chamber heads liking the duration,and not the lift.
Brian,thanks for the reality check,a roller certianly isn't needed..I do drive about 4500+ miles a year.
Heads are untouched.
I'm figuring the cam swap is last on the list.For now,I just want to get the gears done,and go back to the track.And keep driving it graemlins/thumbsup.gif
Javier,thanks for the compliments smile.gif

I have made a lot of changes to my ride. They are:
New rear gears 4.10
New Trans BTE TH400
New Torque Converter 8" BTE Flash Stall appr. 4300
New Shocks/Springs KYB's and stock springs
New Total Front End Rebuild
SSM Lift Bars
New Holley HP 950
In about a week I hope to get it to the track. My goal with this car is 11.5 (I know I wont get there with these changes) I want to tune my suspension and get the car to 60 really well and of course hook. There will be a cam swap in the winter, I just want to see what this thing will do with these changes. I should be going through the traps at about 6000 rpm, which is 300 rpm over peak HP. I will post the results when I get them.

if the car still hooks with the 3.31's, i'll say it will probably run around 4 tenths faster than before. but as long as you're running small headers, small exhaust, and smallish cam, i don't think you'd gain a whole lot from any lower gear swap anyway and probably not much from a convertor since your torque curve is probably on a plateau from 2500 through around 4000. you could stall it to 4000, but what good would it do if you're only making 5-10lbs/ft more torque at 4000rpms as you are at 2500rpms? i might be wrong about the torque, but i'll bet i'm right, that's why the thing runs so well with the 2.73's in the first place. BTW, could you tell a seat of the pants difference with the RPM intake over the previous intake? Good Luck! graemlins/thumbsup.gif

m71,I cannot feel a seat of the pants with the RPM intake.On the torque thing,cmt454 built my motor identically,except he used the 2.19/1.88 valves..his motor made 490 HP at 5500 rpms and 525 ft./lbs. of torque(peak) at 3900
I don't recall the curve from 2500-4000
My current cam specs are:
advertised 280/288
221/231 @ .050
.525/.550
112 LSA

Chris, the numbers were 491HP@5700 and 532Ft.Lb@3900 ;) I did have the larger valves installed as well as some port work done. I suspect your torque curve would mirror mine. Even at 5000rpms I still had a little over 500ft.lbs of torque. I wanted the converter to flash 300 or so higher than peak torque and the gears to have me crossing the line at or about 6000. With the 3.31's I was crossing the line at about 4500 or so. The car definatley accelerates a lot quicker, but the real proof will be the time slips. I think the dyno pulls started at 3000 rpms. I dont recall the numbers under 3900rpm

Chris,thanks for correcting me..I knew I was in the ballpark smile.gif Impressive numbers for sure graemlins/thumbsup.gif

cmt454, what size headers were used on the dyno? i know alot of dynos use larger headers than what most of us actually run in the car which makes peak power numbers high, but doesn't really show an accurate torque curve for what the engine does in the car. from the combos you guys have, i would think the torque curve is very long and smooth, not peaky, which is where the convertor and gear swaps would make more of a difference. my 454 had ported oval ports and a solid roller that was 260/270@ .050 and when i swapped from a generic 3000 stall that flashed to 4200, to a 4500 stall that flashed to about 4700, i gained absolutely nothing. i think i was already past peak torque with the first convertor. i also had a single plane intake and 2" headers with 3 1/2" exhaust...everything i had should've been much higher rpm oriented than your combos are. maybe mine was a fluke. :confused:
i never ran anything but a 4.10 gear in it, so i can only speculate what higher or lower gears would've done for it. let us know when you get back to the track. graemlins/thumbsup.gif

Originally posted by mr 4 speed:
I recently swapped to an RPM intake-no other changes..previously ran a Performer.
Now,I haven't been back to the track yet,and I usually make it a point to go back when something in the combo changes..chances are though,I will be going back in late summer or early fall and have not only the RPM,but 3.31's installed as well.:( I was looking forward to seeing what the intake change alone would do.

Rod

If you were thinking a roller, and I too would certainly skip an SR in your situation, despite the dislike of hydraulic rollers on this site, they will easily, easily crank 4500 miles a year, year after year. It won't rev like your 280/288, but the right hyd roller has its place.
I haven't been to the track to test my new converter yet to see if it was a culprit in my combo for a number of years (planning on sat july 31st-NED, no time for weekday drags right now), but if it wasn't, I am switching back to a hydraulic roller, but a "meatier" one like I was looking at before I was persuaded to go solid. Before i do that I would give a few more shots at the track and also put my lash at .020/.022 or .020/.020 vs .016/.018 (or does the exhaust need a different lash because the valve gets so hot?)
I had a line on some nice cammotion grinds (this was at the time time harold was in transition).
Hyd rollers have their place, and do work well, esp in a high performance street/strip car that sees alot of street. They don't install them in new vettes because they don't work.

matt (I was going to email this to you, but i couldn't find your email address or the little "send email to user" w/o knowing their email function..?)

Rod,the 3.31's aren't in yet..so a run with just the RPM swap might be possible..wish the damn track wasn't a 2.5 hr. ride :(
Again,I want to stress other than the 3.31's going in sometine in the next 2 months,I don't plan on any changes yet.I'd actually like to get a few runs with just the RPM as I mentioned,than run again after the gear swap.Who knows,nothing might not get swapped out for next year,other than a possible convertor (and the gears)The motor runs great,and I don't really want to touch the valvetrain..it is nice to know what choices there are if I decide to do something.

Sorry-- I reread the post and answered my own question. (was about your converter)
I can't wait to test my new converter though, I honestly can't tell one way or the other if its faster. Converter slip is down a good percent at 40mph, but I have no idea if or how that would equate when the converter hydraulically locks and what it would do performance wise..

Matt

I love 70 Chevelles....wish I still had mine! It started life as an SS396....pale green with the green vinyl top. And honest to god, it was owned by a little old lady.
Enough of that.
I built a mild 454 for the car, and tweaked it over a year or so and it ran a best of 11.9 @ 112.
The combo was simple.
Casting #215 heads, pocket ported by myself with the stock 2.06/1.72 valves. I back cut the intakes on a lathe.
Pistons were flat top TRW cast replacements.
Cam was a Comp 280H set up a few degrees retarded.
I had a Performer then switched to a Performer RPM. 750 Vac Sec Holley. HEI ign, curved of course. Also had a B&M 11' 2400 hole shot till it broke after only 500 or so passes, then switched to a 10" Holeshot.
I really can't remember if I had 1.75" headers or 2"? I think they were 2" Hooker comps.
Also had a 3" exh (mandatory I think on a 454) with Dynomax monster turbo muffs.
Gears BTW were 3.55's, but I doubt 3.31's would have made much of a diff. (Currently have a friend who has run 10.95 NA with 3.31 gears and a 454)
FWIW about gears.....
Big blocks don't care all that much. They torque so well, too low of gears probably hurt if the engine is all done by 6000. Add taller gears, and the converter just flashes higher...as long as it hooks up.
I used slicks......Chevelles have plenty of room in the trunk!!!! Steel wheels, a battery powered drill that will turn the lug nuts quick and a floor jack, you can change both sides in 15 minutes or less.
The secrets are in the intake and exhaust. Get both to flow, and the CID will take care of the rest. This includes the heads BTW....but yours are fine. Somewhere between closed and open chambers. Make the car hook and go fast! My old green heap surprised more than a few folks, but there was no magic. I can't tell you how many 454 Chevelles I've seen that ought to run low 12's but actually run 13's.
Keep up the good work! Yuo WILL get there.
BTW....I also drove my car every day......and even on more than a few long 500 mile road trips. Passing Semi's on the 2 lane highways was an absolute blast!
Ron