Am I Maxed Out?

[stroker1]

Just wondering what you guys think. I was hoping I could make it to the 6.50s but not having any luck so far. And other than going to a T-brake I'm beginning to wonder what will speed it up.

Combo is: S-10 long bed with caltracs, 8 pt. cage, aluminum dash, 1 racing seat, no fenderwells, lexan back glass, fuel cell, 9" rear end w/4.56 gears, PG with 1.82 first gear, 383 sbc Performer RPM heads (170 runner), 13.3:1 compression, 6" rods, internally balanced, cam is .640"/.604" 256/268 @.050" 102 ICL and 106 LSA solid roller. 8" converter footbraking to 3000, Hussler Fenderwell headers 2" tubes with turnouts, tall single plane manifold, Holley 750 double pumper w/Proform mainbody and baseplate, electric water pump, 28 x 10.5 slick, front trick springs, SUCKWOOD 90/10 front shocks, Centerline Convo Pro wheels 3.5" front-10" rear, and 1 stage plate shot NOS Cheater kit.

Here's the deal. Locked timing out at 32 deg. I've jetted it 63N/71F and went 1.51 60ft 6.60 ET at 106 mph for best ever. And have gone 6.666, 6.666, 6.696, 6.71, all on the same jetting with 60ft right around 1.55-1.57 usually.

Then went to square jetting 63N/63F and went 1.55-1.57 60ft. and 6.65-6.71 ET at 106 MPH.

Then went to 71N/73F and pulled 1 more degree timing. This Saturday at Fayetteville it went 1.53 60ft. 6.63 ET and 107 MPH.

It don't seem to respond to the change in jetting and the 60ft. does seem to suck! Am I doing all it will do with the little heads and no T-brake?

[ZIPPIE1]

stroker has your heads ben worked on.or are they stock no porting or valve job.what rpm are you turning do you know.i dont know about the nos. because i dont use it. but to me it seems if your not geting enuf air. your 60 should be in the 1.40s to 1.50+ or so. how far will your stal go to? do you just run the 1\8 only you might could put lower gears in it. easer is toput shorter tire to see if it works i might be wrong. just my opinion . god luck





jason

[stroker1]

The heads have some nice porting. Both in the valve bowls and the runners. But they are not really opened up much in the runners. Mostly opened up in the valve bowls and blended around valve guide bosses. I don't turn but about 6200 rpms unless I'm in the water. I only run the 1/8th. 4.56 and 28" tire makes too much rpm for my motor in the 1/4 mile. Stall foot brakes 3000 and flashes about 4200-4400.

Don't get me wrong fellas, I'm pleased with my little motor and I think it's doing good. I just don't want to be beatin myself up if it ain't going to get no faster. But I do like to squeeze everything out of it that can be got. So if the motor ain't going to do no more than it's doing then I'll start looking into maybe a T-brake, and eventually some heads and a cam.

I'm the kind of guy who uses the soap in the shower until it is as thin as paper. I like to get the goody out of something. But I don't like pissin in the wind. Especially up wind.

[grimpuppy]

Do you not want to turn more than 6200 rpm? Your cam and headers are quite a bit bigger than mine. I am just starting to make good power at 6000 rpm. I wouldn't say you have maxed out your combo when you are only turning 6200 rpm. If you want to squeeze all the power out wind up that motor.

[mudy851]

I agree next step is to bring up cam and head size needs to be at 200 plus on runners on your set up.My self i run 320 runner 12 angle swirl port and polish canfield heads with a cryogenic block.

[stroker1]

Oh yeah, I agree I could benefit from a better set of heads. But I'm wondering is there anything left in my current combo without going to a bigger head? Grim says spin in harder. But I don't think it likes more than 6200 because of the small runners. My motor makes good midrange torque and horsepower. But starts to fall off at 6000 and at 6200 it will drop in power rapidly according to my computer dyno. So I tried it a couple of times to 6400 and it ran the same one pass and the other pass it slowed down .015 seconds.

One thing is, do you guys think it will work better to put the 1.6 rocker on the exhaust for spray? It works better for the 1.6 to be on the intake when on motor only. But the n20 might like more lift on the exhaust to help get them big 2" tube headers working. Hows that sound?

[mudy851]

The old saying is the more you feed the more it has to breath,but i think you have alot left in the motor now its just finding the little things to let it out,rockers are a good way to start i run combo 1.5 and 1.6 harlands on my drag truck and it helps to let it do its thing.but the key factor is budget.my drag truck i've got 21.000 tied up, but result is 872hp. almost to the point of out of control, hence the reason i'm building a tube chassie truck for the new motor.have you tried using desktop dyno 2000 to work on some combos i find it helps fine fact. it might be right but will be close.

[rayL]

872 hp....i wanna hear more about this.

stroker..........640"/.604" 256/268 @.050" "102 ICL and 106 LSA "

what kinda intake do you have?

[stroker1]

872 hp....i wanna hear more about this.

stroker..........640"/.604" 256/268 @.050" "102 ICL and 106 LSA "

what kinda intake do you have?It's a Profesional Products elcheapo china made tall single plane with about 6 hrs worth of porting and smoothing to get the rat terds out of the runners and port matching. Also allot of smoothing in the plenum, it had allot of casting flash in it. It's opened up pretty good. But I'm sure it's no Super Victor or Dart, or Brodix HVH. But I can tell ya there ain't no difference in it and a Victor, Jr. They both ran the same, and the Vic, jr was borrowed so I gave it back.

[grimpuppy]

It doesn't make sense that the heads won't support more than 6200 rpm. Even with a 170 runner it should be better than that. When I had my bowties on they would turn more than 6200 without nosing over and they were small runners. They aint near the head the performer rpm's are either. If them heads will only let you turn 6200, then you are pretty much maxed out because your cam and headers want to turn more. I don't see how more lift is going to help by changing the rockers. If the runners are that bad, how are they even supporting a cam with .640 lift? Most small runner heads start to lose flow after a certain point. If the heads can't support more rpm that, there is a possibility that the cam has to much lift for the heads and it is hurting your flow. That would be the only reason I can see why them heads wouldn't make power over 6200.

[stroker1]

It doesn't make sense that the heads won't support more than 6200 rpm. Even with a 170 runner it should be better than that. When I had my bowties on they would turn more than 6200 without nosing over and they were small runners. They aint near the head the performer rpm's are either. If them heads will only let you turn 6200, then you are pretty much maxed out because your cam and headers want to turn more. I don't see how more lift is going to help by changing the rockers. If the runners are that bad, how are they even supporting a cam with .640 lift? Most small runner heads start to lose flow after a certain point. If the heads can't support more rpm that, there is a possibility that the cam has to much lift for the heads and it is hurting your flow. That would be the only reason I can see why them heads wouldn't make power over 6200.
Beats me! But I can assure you it has got a ton of cylinder pressure. So it's got to be moving a fair amount of air. And the dynamic compression is high, but right off hand I don't remember what it is. BTW, according to my Performance Trends dyno it's suppose to fall off on power around 6200 and that's what I'm seeing. Grim I don't know how you figure the cam and heads wants more RPMs. My cam is a stump puller almost. The HP and TQ lines are very peaky, which is typical of a close LSA cam. It jumps up fast but falls off fast. It's a GET'R done in a hurry cam and works pretty well I thought with the small heads. But I don't really understand why she will not pick up more than 2 tenths or so with a 150-180 shot. That's just puzzling me. That's why I wonder if my cam and head combination has reached it's flow max.???? Sure if I changed cams it would probably turn a few more revs, but would lose a little midrange. Oh, and concerning .640" lift and being too much lift, I don't know but the cam guy told me it would give the valve more time at optimum lift. So lifting it more is not really what they where looking to do. For my application, it's the ratio of the 1.6 rocker that holds the valve at the sweet spot longer, so they told me. And that makes sense to me because the valve only stays at max lift for a slim fraction of a second.

Anywhoo.....does anybody know of something running faster than mine with the same heads and cubic inches? And I mean first hand, not no hear say stuff. If so I sure would be interested in knowing what the combination is. I'm pretty happy with mine, but would always be interested in squeezing a little more out of it.

Thanks for the comments, they are all helpful and make good discussion.

[grimpuppy]

I see where you are coming from stroker. Let me try and clarify what I meant by your cam is to big for your heads.

Most small runner heads flow well to a certain lift. Well designed heads will keep flowing that same amount after that point no matter how much farther you open the valve. Not so well heads will actually flow less the farther you open the valve past this point. Vortec heads are an example of this. They fall off very bad after .550 lift. Your RPM heads are well designed. On the flow sheets I have seen on the rpm heads they flow the same cfm at .550 lift as they do at .650 lift. they do not fall off. That is why I didn't think it would do much good to increase your lift. You are actually at max flow right now starting at .550 give or take what your pocket porting has gained. All the cams I have looked at with your specs show a rpm range to about 7000 - 7200. I have looked at several because you have a solid roller version very close to my solid flat tappet. I have looked at several cams in your ball bark because I have looked at getting one with specs similar if I upgrade to a solid roller. I never upgraded because when I flowed my bowties they maxed out at .560 lift. Now that I have the darts, I have started looking again at upgrading, since I can take advantage of the increased lift. I am not a cam expert by any means but that what I was referring to. This is all good information from everybody. I am learning some things here also.

My previous combo was 4 tenths slower than yours is now on motor with out of the box bowtie heads, .530/.550 250/250 solid flat tapet cam and 1 5/8" headers. So I think you are getting quite a bit out of your combo now.

[gottago]

The Edelbrock performer RPM heads are under rated, I was running them on my 358 SB and shifting it at about 7000-7200 rpm's and there was no drop off in pull. I would try buzzing that thing up 500-600 rpm and see what happens. Your cam and everything else can sure handle it. Maybe see if you can borrow a 850 double pumper from someone and see if that helps, I picked almost 2 tenths going from a 750 to a 850 on my 358. I used the 1 5/8 shortie headers with turn outs and the comp 306S 260@50 and 594 lift with 1.6 rockers.

[stroker1]

I'll spin it a little harder and maybe try a little different timing and see what it will do. I've done it before but I'll try it again. I'm really interested in seeing what it will do if I swap the rockers around and put the 1.6 on the exhaust. I mean sense I've got the giggle gas on it that should help fill the chambers so maybe I will benefit from the extra lift on the exhaust to help evacuate the cylinders faster. With the headers I've got they will handle any kind of exhaust flow a small block head is capable of throwing at them. So I don't worry none about my headers.

[DuskTillDawnLL]

Also, what is your bottle pressure at?

[OH_YO]

Also, what is your bottle pressure at?

True......I never leave the line less than 1050. I dont purge it at times to make it leave softer.

[rayL]

its not gonna pick up much more with that camshaft on the spray. Whats the cranking compression on that motor? Im not familar with those heads at all so i just flat out dont know anything about them. In general, nitrous motors like big stuff. Big heads, big exhaust, big intakes, big ..stuff. Flow isnt really a problem but with small runners and not alot of cross section you start getting into reversion and some other technical mumbo crap that equals about what your talking about. Little or no gains on increased shot. Did you say your total timing was at 32?

[stroker1]

I try to keep it right around 1050 when I launch. And I had been only running a 63N/63F jetting so that shouldn't have dropped pressure really fast. And I'm only running the 1/8th. We had a spill at the track one night and my torch took a crap and had to launch at 900 psi and it ran 6.696 that pass which was my 3rd pass. And that compares to my 1st pass 6.666 and 2nd pass 6.666 when I launched at 1050, so I don't think that is my issue really. But good question.

Please don't say nothin about my torch---I know already. However as dangerous as it is,.....I try to use as much caution as possible. I cap the bottle and open the valve to read the gage while fanning the heat at the bottle. I only do this to boost it a little when it's not heat soaked enuff. And also to boost it a little if it cools in the staging lanes.

My 60ft. sucks on motor and spray. And it ain't much difference either way. And it might be spinning a pinch but it ain't blowing the tires off usually unless the track prep is poor. I sure will be glad when I can try a brake on this thing.

[stroker1]

its not gonna pick up much more with that camshaft on the spray. Whats the cranking compression on that motor? Im not familar with those heads at all so i just flat out dont know anything about them. In general, nitrous motors like big stuff. Big heads, big exhaust, big intakes, big ..stuff. Flow isnt really a problem but with small runners and not alot of cross section you start getting into reversion and some other technical mumbo crap that equals about what your talking about. Little or no gains on increased shot. Did you say your total timing was at 32?
Hey Ray, You sneaked in there. OK, hold on and let me work something up here.

Yeah, timing was at 32 with the 63N/71F and then went to 63N/63F. After seeing absolutely no gain with square jetting I went to 71N/73F then pulled 1 more degree timing. That only picked up .02 seconds and 1 mph. went from 6.65 @106 to 6.63 @107.

[stroker1]

Ray, cranking psi on my motor depends on piston speed. But if you spin the motor over 2 or 3 revs with the gage on it will hit around 245 psi.

[rayL]

Ray, cranking psi on my motor depends on piston speed. But if you spin the motor over 2 or 3 revs with the gage on it will hit around 245 psi.

way to much, for spray, its not gonna pick up much more. Id look into getting a more nitrous friendly camshaft. Its gonna slow down on motor but will be much faster on the gas.

[rayL]

How much lift can you clear?

[ZIPPIE1]

rayl let me ask you i changed from a 314-325 duration 850 lift to a 288-292 duration at .@50 600+ lift will it make a big deference it would scream before but now i keep breaking stuff.supposed to have according to the guy i have do my machine work. from his desk top dyno i have 650+horse at 6500-6800

jason

[rayL]

rayl let me ask you i changed from a 314-325 duration 850 lift to a 288-292 duration at .@50 600+ lift will it make a big deference it would scream before but now i keep breaking stuff.supposed to have according to the guy i have do my machine work. from his desk top dyno i have 650+horse at 6500-6800

jason

need more info. 850 lift?? what kinda motor is this?

[rayL]

Hey Ray, You sneaked in there. OK, hold on and let me work something up here.

Yeah, timing was at 32 with the 63N/71F and then went to 63N/63F. After seeing absolutely no gain with square jetting I went to 71N/73F then pulled 1 more degree timing. That only picked up .02 seconds and 1 mph. went from 6.65 @106 to 6.63 @107.

something i totally missed was this. 63n/71f =150( and pig rich@5.5#s) then you went 63n/63f( should be clean @5.5#s)..which is only around 125, then 71n/73f( rich@ 5.5#s)..barely a squeak over 150..maybe 155?

Point is the FUEL jet dictates power not the nitrous jet.
Wish you could try 71/71 and see if it picks up then.

[stroker1]

How much lift can you clear?That's a hard question to answer. All depends on the cam and cam phasing. Right now with the 1.6 on the intake, no head gasket, and zero lash I have a little under .080" piston to valve at the closest point. And that would make theoretically .640" lift. But you know what I mean. Depends on how close the intake valve is chasing the piston down the hole.

[rayL]

i have a camshaft that im willing to bet will pick you up a good bit. Its gonna slow down on the motor but i beleive will pick up a good bit on the gas. Its close to what you have now just different valve events. Its a cam motion 258/268 .660 .645 110 lsa. If you wanna try it, shoot me a shipping address.

[OH_YO]

i have a camshaft that im willing to bet will pick you up a good bit. Its gonna slow down on the motor but i beleive will pick up a good bit on the gas. Its close to what you have now just different valve events. Its a cam motion 258/268 .660 .645 110 lsa. If you wanna try it, shoot me a shipping address.


WOW what a guy!! One of the reasons I love this site is the kindness that is displayed on a daily basis. :)

[gdmclnh]

If you look at nitrous design cams they will all have wide LSAs. For better cylinder filling. Most are over 110 deg LSA and many are 114 LSA.

[stroker1]

i have a camshaft that im willing to bet will pick you up a good bit. Its gonna slow down on the motor but i beleive will pick up a good bit on the gas. Its close to what you have now just different valve events. Its a cam motion 258/268 .660 .645 110 lsa. If you wanna try it, shoot me a shipping address.What a guy! I'll let ya know. We will get together on it. Thanks!

Yeah boys, I know I've got a bad cam for n20 and I knew it when I built the motor. I had these Performer RPM heads available to me at a deal and didn't have the money to spray it anyway. So I tried to get the biggest bang for my buck with the naturally aspirated motor. And I believe I did. The cam I have is making a bunch of cylinder pressure, but for reasons that I don't absolutely understand.....it will not pick up much more on spray so I guess it's time for a change. First just for the heck of it I'm going to swap the rockers around. Funny how cams work ain't it?

Another thing is, my combo makes killer mph but seems to be off in ET, and also 60ft. I think if I can get my 60ft. down then the ET will improve a good bit too. And I think it should be a 1.44-1.48 instead of around 1.55 with a et of 6.60s.

[muk]

I think you should get bigger runner heads or massage yours 170cc seems too small for a 383 the extra stroke just demands more airflow i'd pull the heads and see how well you can match them to a fel pro 1206 gasket and go as deep as you can the bottom end is basically an air pump and can only pull as much air as the heads will let it i would get a burret and check yourself frequently and try to see how close you can get to 200cc. or sell the ones you have and buy second hand i got my bare brodix heads for 400 from the local performance machine shop they were trade ins.

[ZIPPIE1]

ray L its is a 406ci 11.75 comp. zero deck height 3.75 stroke forged pistons. .40thousandths head gaskets.5.7 rods. 288-296 duration@ 588-600 lift . took out 314-325 duration @50 850 inch lift.gas. and50%nitro methane i keep braking trans. putting roll cage in it now.

[stroker1]

ray L its is a.........288-296 duration@ 588-600 lift . took out 314-325 duration @50 850 inch lift.gas. and50%nitro methane..........

You might want to double check them cam specs your spitting out there!

Sumfing sown wong!!

[ZIPPIE1]

with cam are you refferring to both are custom ground cams.both solid roller that was supposed to be @50 with lift 588-600. small base circle.it was 286-291 .center 106 centerline104 thats on my cam box.zero lash. put wrong numbers there 314/325 goes with this cam. the other was 305 /314 dont remember @50 with 850 lift

[stroker1]

with cam are you refferring to both are custom ground cams.both solid roller that was supposed to be @50 with lift 588-600. small base circle.it was 286-291 .center 106 centerline104 thats on my cam box.zero lash. put wrong numbers there 314/325 goes with this cam. the other was 305 /314 dont remember @50 with 850 liftBTW, Thanks for high jacking my post!! LOL I dont even know what you're asking but maybe Ray understands it??!! Might want to try a private message.

[rayL]

zippie... yep looks like cam numbers.

[stroker1]

Daggum water still getting into my carb somehow. The dang foam in the fuel cell must be retaining moisture from the Dr Pepper pecker heads vandalism. I think I'm goint to remove the foam from the fuel cell. And maybe sit it out in the sunshine. I don't know how else it can still be getting moisture into the gas. I've kept this thing in the garage ever since the vandals struck. I think I'm going to add a bottle of water remover to the next fuel I put in.

Reason I found it, I changed jets again b/c plugs are still sooty. Even the low speed fuel ring. I'm at 72 front/80 rear with rear power valve blocked. Should make a little more power now and should be a pinch lean or just right on motor. Then I'll see what it looks like on the bottle. I'm also going to swap rockers tonight and put the 1.6 on the exhaust side. Maybe I can get a 6.50 out of this thing one day.

Question: Will a bottle of water remover (most likely made up of isoprophyl alcohol) hurt the foam in my fuel cell if I go ahead and mix it with the gas before pouring it in? I know alcohol will destroy fuel cell foam, but how bad would a pint hurt it?

[grimpuppy]

Why not just leave the foam out??

[rayL]

or get new foam?

[stroker1]

Slowed down allot. Well I tried the 1.5/1.6 rocker arm combination. Switched from 1.6/1.5 and also went to leaner jets on the carb (72P/80S rear PV blocked.) Somewhere along the way I slowed down to a 7.00 on motor and 6.76 on a 180 shot with 71N/71F jetting 5.5 psi fuel enrichment which should be more like a 190 shot. 60 ft was a bit slower, 1.54 on spray and 1.57 on motor.

BUT, the truck did seem to hook initially. I'm not sure it didn't spin a little after the launch. And boy did I have surging problems on the top end. Never had that before tonight. I wonder if it is related to removing the foam from the fuel cell. I had 5 gallons in a 14 gal cell. (the cell was free, but way too big.)

PS: Missed the RNC for this crap. What a disappointment. At least I got to see Palins debut last night. Personally I was very impressed. But don't want to get nothing started here, that should go under a different thread.

[rayL]

are you spraying dead out the gate? i just dont see how you can only pick up 3 numbers. you sure you arent killing the converter?

[stroker1]

are you spraying dead out the gate? i just dont see how you can only pick up 3 numbers. you sure you arent killing the converter?I agree on the lack of results. About .2 to .3 seconds is all I'm seeing. I don't think I'm blowing thru the converter. RPMs are not jumping thru the roof.

Ya think my stock hood with no cowl may be sheilding the carb and it's starving for air?? It has a gap between the carb and hood but it ain't much. I'm certain you can't fit your hand between it. This just kind of struck me as I was wondering how can the n20 not be putting more air into the chambers. It's not picking up for some reason. And last night it was very noticeably surging (maybe air in the fuel enrichment line or pressure moving around) but still I think something else is not right.

[asfasasu3]

I don't know about your most recent problems, but I would tend to agree with the others in that you don't have enough head flow for the motor. I used to bracket race a 78' Malibu (3000 lb street legal) with a 383 and it would run 7 flat, at 96 mph, all night long with alot less cam. (.575 and .550 lift) less compression (flat tops with 64cc heads) and no juice. (but with a decent set of heads) The best bang for the buck that I did, was to switch heads. I went from the ole dumble humps with 2.02 and 1.6 to a set of World products Sportsman 2's and picked up almost a full second in the eighth. Nowadays, theres no reason to not have a set of heads that work with your combo. Theres so many out there now you can pick exactly what you want. Man I wish I had that car back !!

The new problems sound like they could be fuel related. (just like you mentioned.) I'd start back at the fuel cell and work your way back to the jets. It sounds like it didn't like the 1.6 on the ex side. (which also goes back to the heads thing) Its all fun trying, but it can be REALLY TRYING some times. GOOD LUCK!!

[OH_YO]

Get that truck fixed before Super Chevy cause you coming up to run with us.:)

http://www.bristoldragway.com/events/super_chevy_show/

The event we are running.------>Tremec True Street Challenge.

[stroker1]

I don't know if I can make that, probably not. I can't afford it and my car trailer can't stand the trip either. I need some trailer tires pretty bad. So I need to stick around home for awhile and save I guess.

Thanks for the invite!

[oncearacer52]

I fought something like this for weeks. Your 60 ft. is nowhere where it should be with your 6.60s times. I agree the heads may be hurting your performance but I don't think they are hurting your 60 ft. times. I too try very hard to make what I have work. I am wondering what brand of tire and what compound are you using. My problem was the tires were wore out..... I use Hoosier 30X10.5 DO5 (very soft) with a 4.11 gear. You have a 4.56 with 28 inch tires. I have Slide-A-Links you have Cal-tracs. I have a long bed you have a long bed. We are very similar. I was losing traction LONG before the tires showed worn out. With the new Hoosiers I dropped a tenth on the 60 fts. You are geared way lower than me so I wouldn't be surprised if you aren't starting to lose your tires.

[stroker1]

Yeah, you have a good point. I really do need some tires. I need to go ahead and buy them and be done with that possibility. I really hate to buy stuff to fix a problem and the problem remains, but in this case I need them regardless. I can see that they are about gone.

I guess I should stop my whining and save up for some tires. But still I'm disappointed in the way it fell off from the rocker swap and carb jetting. Thats another factor to figure in. Was it in the carb jets or the rocker swap that made it fall off? I'll have to do some detective work to find out I guess.