Solid Vs. Hydraulic Cam for 383 I want more!!!

[deputycrawford]

My 383 specs are:

  Block:     Steel crank, stock rods, Flat top pistons,1/2 inch oil pick up, 7 Qt pan, internal balance, Total Seal zero gap rings, windage tray, full groove bearings, Comp high lift cam, 545 lift 241/247 dur at .050, ARP bolts ETC.

  Heads:   906, 75 CC chambers, port matched and smoothed, three angle valve job on stock size valves and un-shrouded, Comp Chromemoly adjustable 1.5 to 1 roller rocker system. 9.5 to 1 comp

  Extras:   Eddy RPM intake, smoothed and port matched, MSD pro billet dist and 6AL box, Mighty Demon 750, 1/2 in fuel line with 1/4 return, 120GPH mech fuel pump 6PSI.

  Driveline:   Rick Allison Trans (A&A) W/ 9 1/2 inch Converter (3500) stall, 4IN drive shaft, 1350 yolks, 8 3/4 W/ 4.10 gear and sure grip.


Here's my question: I have run a best of 13.19 at 102 with a 60 ft of 1.84 at Milan dragway in Michigan. This is a 4000 lb car with me in it. Thats not bad but I want much more. I would like to go to a solid lift Hughes cam with around .580 lift before lash and 250 to 260 dur at .050. I don't mind losing a little street manners but is it too much? I'm looking for mid 12's. Should I also put the bigger valves in the 906's? Money is a bit of an issue. Oh, I have XHD R/T springs on the rear from Mancini's and 960 Torsions on the front. I put cheap "c" body shock on the back and will put 90/10s on the front in the spring. Is the cam gonna give me much more?

[firefighter3931]

Nice setup. As you probably know the power is in the heads and cam. Comp has a nice grind that would work well with that combo. Have a look at the XS282S solid flat tappet profile. A few members here have had good luck with it so far. Some bowl blending would really help pick it up. If you haven't used the MP porting templates, get them and grind away. 

Ron

[deputycrawford]

Thanks firefighter. I believe that the heads have been blended.I say that because everything has been touched with a grinder. The bowls and ports looked very smooth. The only thing they didn't do is open the ports and flow test them. They have all the equipment to do that, as well as two dynos in the place. I'm speaking of Autocraft Engines. Many people have heard them. I was wondering how much would I pick up with the bigger valves? Also, the motor seems to be out of RPM by 6000 RPMs at the most. I am starting to believe it is the lifters that can't take the aggressive ramp angles of the new grind. What do you or Chryco think. I will take all input into thought. I usually run with Chryco's and your input. You two seem to be in the same ball park all the time. I am willing to put the power band into the 3000-6500 RPM range. I don't care if the cam comes on as high as 2800- 3000 RPMs. My converter and gear will get me down the road OK. Yes, my screen name is correct and I drive it to work. My Sergeant yells at me that it is too loud and I just laugh at him and tell him I'll give him a ride. He won't even get near that thing. Need more power!!!

[deputycrawford]

Oh yeah, Should I use a tight lash cam or will a larger lash cam do ok on the street? Remember I am willing to check lash a couple of times a year and will put up with the noise as long as the car is in the mid to bottom 12's. I only put around 2000 miles on the car a year,weather permitting. I tend to like the higher lift to duration cams of Hughes but would custom order from Comp or what ever company I need. What duration should I max out to shift at 6500 RPMs? It is the original block and heads. I have lots of valve clearence for the big cams. I had it checked when the engine was being built. They even hand sanded my mains until I had exactly .002 clearance on all mains and rods. Even the rings were gound to specs. They took their time with the engine. I just need to step it up a bit.

[Ghoste]

Say Ron, if I can indulge in a little threadjacking here, what solid cam would you pick for my 383?  Just being curious.

[Runner]

dont take this the wrong way, but i think it should be faster the way it is.     id be looking at the tune up.   whats your total timing at?.   383s love lots of timing.     my thought is,   getting a 383 to et in a heavy car is done with gear and converter.   i dont think there is 7 tenthes in a cam change though... but thats just me.     i might also take a hard look at the valve springs.



     my roadrunner's 383 (wich is 250 pounds lighter) ran a best of 12.49@109 mph. even with the added weight it would have ran 12.70s-12.80s.     the parts in that are,   a nicly rebiult set of 906 heads but no grinder work, tm6 intake cheap badger pistons at 8.9-1 cr( measured) mopar 484 cam, stock valvetrain with good springs. holley 750 dp and a tm6 intake. t/a 10 inch converter and 4.57 gears.     

     my 68 satellite   (about 350 pounds lighter than your car) ran a best of 13.80@ 102 mph on street tires spinning, with 3.23 gears and a absolute cheap budget rering engine.     it has 9.4-1 cr, stock 516 heads, a torker intake(i had it on the shelf, definatly not the right intake for this engine.   it now has a rpm intake on it) a crane 272 cam. a 3310 holley carb.   this is my daily driver and it idles with just a hint of lope and gets almost 15 mpg.     
 
i now run a 452ci engine in my roadrunner with the comp xe282s that ron metioned, with the same stock heads it went 11.80 with e-heads i dot know what it will et in the 1/4 but it ran 7.33@93.95 at our local 1/8 mile and its acually a lamb compared to the 484 camed 383 that it replaced .
 

[Runner]

Say Ron, if I can indulge in a little threadjacking here, what solid cam would you pick for my 383?   Just being curious.

  im not ron, but hey ill throw this out there anyway.  if you are starting from scratch with nothing extra for parts, giong solid is giong to cost some cash.   200+ for a new cam and lifters. a minum of 220 for adjustable rockers (new)  90 bucks for push tubes, about a hundred dollars for new springs. so by the time its all said and done it wil cost 550-650 dollars. then there are other things to consider, stock heads can only take around 500 lift before the retainer hits the giude. and do you have valve notches in your pistons (im betting not as MOST 383 pistons dont )   and remember, valve lift doesnt determine weather youll have piston to valve interferance, duration does does.  i also seem to remember that you have a 2000 stall converter?    what you have in parts, its giong to need a pretty small solid lifter cam.

   if i was giong to do a cam swap in that engine id be sticking a comp xe262h or a comp xe 268h hydrolic cam in it.   if i wanted solid lifter cam i would stick a comp xs268s in it. id be running this past porter racing heads and id be ordering it from him.


    however if it was my car id be calling paul forte at turbo action and getting myself a 10 inch converter shipped and then you will be able to enjoy that 484 to its potintial, plus if you decide it isnt enough, youve just opened yourself up to alot more selections in cams.


 
   

[Ghoste]

Not starting from scratch.   That's why its threadjacking.   I've been picking Ron and Neils brains partly here and partly in pm's deciding what to do with this car over the winter.   Part of me wants to do a cam swap, part of me wants to make the combo work as it is (which likely means gear and/or converter) and part of me just wants to cut my losses and run.

[deputycrawford]

I'll take constructive criticism any day. I thought it should be faster too. I have spring pressures of 130lbs on the seat and 340lbs at .545 lift. The guides were cut down far enough I could run .800 lift. my total timing is 35 degrees by 2500RPMs. I found it alittle faster when I backed the timing down to 32 total. Poor quench maybe? I do have a 4.10 gear, a Dynamic 9 1/2 in converter at 3500 stall, and drag radials I run around 12 lbs in. I put a dot on the tire at the valve stems and they are not there any more. The tires are creeping around on the rims. Remember, I'm between the Irish Hills and Detroit. I'm a bit above sea level but I should have more in that combo. The motor just falls off before 6000 Rpms. I have plenty of valve spring pressure too. I have the 750 Mighty Demon. Could I use more carb too? 850 Mighty Demon? I would like to try cam and carb. I definitely don't see 7 tenths with a cam but I hope to gain it with both, and better 60fts. I'm still working that out. LOL

[Runner]

deputy, your 60's are in line with what i was running. mine was a best of around 1.79 but usually in the 1.81-1.83 range but your mph is lower so it does look like a power issue.  im really surprised the car is faster with 32 degrees of timing. are you sure the balancer is marked correctly?. a 9.5-1 383 running its best et at 32 degrees just seems odd to me. i would of been trying at least 38 and possibly even 39 or 40. the short stroke of the 383 doesnt give the piston near as much dwell time as a 3.75 stoke engine gets.   my car picked up bunches of et the more timing i through at it. i would think that the carb is plenty big for a 383, infact a bigger carb and the 60 very well could suffer.

          looking at the comp catilog sight it looks like you have a comp xe285h cam?.    is the motor a measured 9.5-1 cr?.    you might find some dyno time well worth the money.   god knows you probably have piles of them n your area.

[firefighter3931]

The motor just falls off before 6000 Rpms. I have plenty of valve spring pressure too. I have the 750 Mighty Demon. Could I use more carb too? 850 Mighty Demon? I would like to try cam and carb. I definitely don't see 7 tenths with a cam but I hope to gain it with both, and better 60fts. I'm still working that out. LOL

Hydraulic lifters are pretty much at their limit by 6k. The lifters are more than likely pumping up and floating the valves. This is why i prefer solid flat tappet grinds for high reving motors. It's also possible the heads aren't moving enough air but i'm more inclined to believe the lifters coupled with the htl grind are the problem. I'm surprised to hear it made it's best power at 35* total....usually iron headed combo's like 38* or sometimes 40-42* if the static compression is low enough.

I think the tuneup needs to be looked at as Runner (Mike) suggested. An appointment with the chassis dyno would go a long way to optimizing the ignition and fuel curves. If i had to make one change on this combo it would be the cam. I would also want the heads flowed to see how much air they move and where it stalls. Sometimes folks will attempt to port their heads and actually hurt the flow numbers.

Ron

[firefighter3931]

Say Ron, if I can indulge in a little threadjacking here, what solid cam would you pick for my 383?   Just being curious.

 
    if i was giong to do a cam swap in that engine id be sticking a comp xe262h or a comp xe 268h hydrolic cam in it.     if i wanted solid lifter cam i would stick a comp xs268s in it. id be running this past porter racing heads and id be ordering it from him.


     however if it was my car id be calling paul forte at turbo action and getting myself a 10 inch converter shipped and then you will be able to enjoy that 484 to its potintial, plus if you decide it isnt enough, youve just opened yourself up to alot more selections in cams.


 
    

I think the 268s ground on a 112 lsa would work well. You need something with shorter .050 duration numbers with a low stall/heavy car. The 383's shorter stroke isn't exactly helping in the torque department as compared to a 440. I still like that Crower grind we talked about for a hydraulic with your stall and gears.

Ron

[Runner]

the lifters may very well be causing some problems   i zinged the crap out of my 484 hydrolic cam with out issue.    i shifted it at 6300 and went through the lights at about the same, however its a slower cam itried 6500 rpm shifts and ran it past 7k all the time prior to having a limiter.    i think a set of e-heads and the comp xe282s cam would be a nice fit.


     ill give you a 383 combo.    a moparts member and a guy that i race with has a 69 superbee 383. he has a scott brown speced solid lifter cam init.   it is a nice and mellow   232-242@.050.      he went to a 750 hp holley, a set of e-heads and hooker 1 7/8 inch headers. before the swap   it ran a 13.29@ 104mph after the swap it ran a 12.70@108.71

[Ghoste]

Hey Runner, my 383 gets soft after any more than about 35*.  Don't know if it means anything cuz it's a completely different setup than deputy's but I thought I'd mention it.

[Runner]

Hey Runner, my 383 gets soft after any more than about 35*.   Don't know if it means anything cuz it's a completely different setup than deputy's but I thought I'd mention it.

  all i can say is, i ran your basic long block ( basically a stock long block with a 484 cam) from a first outing of 15.80 to a best of 12.49. i tried timing from 33 degress to 40, i tried different gears, and i tried different intakes, underdrive pulleys and 3 different converters.  i know for a fact that my dampner was correct. i tweeked and changed alot of things, but the one thing that remained constant was the long block. it was in the car for 10 years. if your car et'ed better (i dont trust the ass meter.  it will lie to you) with 35 degrees of timing then id say you have other issues,  like your carb is lean and wont tollerate the added advance or your dampner is wrong. its possible the rest of the igntion isnt up to the task.

[Ghoste]

Oh you're so much on the money with that one!  I have many issues and lean carburetion is definitely one of them.  I also think the ignition has yet to be optimized but one thing at a time.
I just mentioned the timing on mine as a sidenote.

[deputycrawford]

Thanks for all the input guys. My plugs always look like they haven't fired yet. They are perfectly clean. even after 1000 miles on them. I will jet up until I get the plugs to look brown. then I will advance the timing some more. Like I said, I'm at 35 total and its fighting up top. The power slows after 5200 or so and I think I hear some spark knock. The carb could just be really lean. I still want to look into solid lifters but will try the fuel and timing first. I must admit, I have been dialing the car in all year. I started with the fresh motor at 13.9. I quickly got it to 13.8, then 13.6 and 13.4. I did this with tire pressure and launch technique. I, of course, got the car to 13.19. That is alot to figure out in one season. The new Demon, I thought would be closer but the weather kept getting colder and I never jetted up. I finally jetted up two sizes but the weather went from 80's to 40's. I guess I need another bunch of jets to figure it out. Thanks again I will post again soon.

[Chryco Psycho]

jetting until the plugs turn brown may not be the best solution , you shoul dbe able to feel the power difference 2 jet sizes apart , so keep up jetting until you fell the power drop off even if the plugs are white , or take it to a good dyno & tune it on there

[Ghoste]

Hey CP, what situations would combine to make you not trust plug readings?

[Chryco Psycho]

after putting a lot of cars on the dynoI have seen some wierd stuff , , it depends on the plug used so I always use champ plugs , & some engines are chalk white at peak power & lose power before even getting any color on the plugs

[Ghoste]

I always use Champions as well.  My plugs are still white but that isn't the norm for my engine so I am guessing I still need to jet up.  It's just speculation for now anyway as it I have to wait for the snow to melt before I can continue with my carb tuning adventures.  I was hoping to get that done before winter hit but I don't have to tell you about Canada do I.

[deputycrawford]

You don't have to tell me about Canada. I live 60 miles from Detroit. I pass the bridge all the time. I will start in the spring with jetting up. I will then put more timing in and run the car. I will then think about a solid cam. One thing at a time I guess.

[Chryco Psycho]

you will feel the difference as you up jet , I would generally rather be on the rich side

[deputycrawford]

Hey Chyrco, I thought something was wrong when 35 degrees total spark knocked and 32 ran better. Demon got me the carb after a million questions. I thought it would be right on. I have jetted up two sizes. I think it is still so lean it might need at least another three. I remember you saying more thatn 5 and something else is wrong. Maybe Demon under estimated my fuel needs?

[Chryco Psycho]

very possible , take it to a good dyno & tune it there , less chance of damage & it will be set right