Here are my motor specs,I will post my times after i see what everyone thinks about the cam with my setup.

385stroker flatop piston 5 cc valve relief
victor jr heads
super victor intake
950 prosystem carb
hooker super comp shorty headers into 3 inch exhuast
titanium retainers and keepers
My cam info is
Solid roller
Dur Int-Exh: 305/310
Dur @ .050 Int-Exh: 260/270
Lift 1.5 - 1.5 Int/Exh: 630/630
Lobe Center: 106
Valve Lash: .025-.025
RPM Range: 3500-7500

Car is 3450 with me in it
Turbo 350 with 4500 hughes conv
ford 9inch 4.30 gears pro spool 35 spline
weld in subframe bars,tubular k-member,control arms front and rear
90/10front struts 50/50 rears
weld prostar 275/60/15 skinneys up front

I footbrake this car and leave at 3k

I have a member helping me with this he suggested i post this and see what everyone else thinks.

 

That's a pretty big cam even for a 385 but should work fine. Those shorty headers will be choking the engine. The 4.30 gears will probably work fine but some 4.56 gears for those 28" tall tires will let the engine reach maximum rpm in the shifts.

Has it been down the track yet? What were the performance results with the old cam?

 

I would think that cam would want more compression and stall to be happy. Those headers are for a daily driver, not what that motor was built for. Hooker super comps in 1 3/4" at a minimum with dual exhaust or a single 3.5" or 4" muffler. Personally I would have chose a cam 5-10 degrees smaller at least at 0.050 with that present combo.

 

Well the car has gone
1.59 60
4.79 330
7.503 1/8 @90.67mph
11.8519 1/4@109.04
with this cam

old cam
1.645 60ft
4.961 330
7.708 1/8 @89.59
12.085@ 111.95

I was hoping to get into the 11.50's. I still dont know the max hp and torque so i have been playing with where to shift, carb tuning. Does it seem possible to get into the mid 11's with where im at now or will i need to switch more things? I just pulled the front sway bar off this week and plan on trying it friday night if its not raining. The car seems to like a 6500 shift. Also what are your thoughts on carb spacer plates? I ran a 1 inch on my current setup and never tried it without it. Any ideas before i go friday would be nice

 

I agree with what the other posters said...but, almost 91MPH in the 1/8th is what my car runs and I have gone 11.60@117. Your 109MPH at the big end is an indication of a problem. Maybe it is lean, maybe you are running out of RPM, maybe the valves are floating. As it sits, 11.50 should be possible.

 

I was also wondering why the mph is off. I know the valves are not floating. I have been trying to get the carb tuned, My first few times out it had a stumble so i switched squirters which fixed the off line stumble. My current jetting is 73/84. I plan to work on jetting this friday i guess i start going up on jets till the mph falls off? Do you go up front and rear or just rears?

 

You're down 2 mph on the top end but have a better 1/8 mile time. You definitely have a top end problem causing you to lose power so a mid 11 second pass is probably there somewhere.

It's hard to say where the problem may be. Perhaps the bigger cam is causing valve train issues. Piston to valve clearance especially with flat top pistons and such a big cam. I don't think I'd want to go more than .550 lift with flat tops. If the valves made contact, they could be bent causing a loss of power. Maybe the bottom of the valve retainer is hitting the top of the valve guide at max lift. Are the valve springs the recommended springs for that bigger cam and are they set up to the recommended install height? Maybe with the bigger cam, the shorty exhaust is just choking it at high rpm.

Do a compression and leakdown test.

 

When we put this motor toghther we mocked the motor up at zero lash plus 3/4 turn. Which means we put clay ontop of the piston,Adjuted the valve lash to 0 and went 3/4 more tight with the adjusting nut. We pulled the head and still had no hitting of valve to pistons. The cam calls for .25 valve adjustment intake and exhuast. So i their is no way i am having valve train issues. The heads where set up at a machine shop with the correct install height and closed and open pressure springs are good for up to 720 lift and have no coil bind or have no retainers hitting. I am thinking it more of a carb/airflow problem. Im not much of a carb guy so im struggling with getting it correct.
I have a freind that is a crew cheif for a guy that hold 11 world championships and also has a third gen and first gen. He thinks it mostly carb problems. The first time we went to the track the car would only run 11.98 and the 60 was real bad, He moved the 50cc pump to the back and the 30 cc upfront and went up on the squirters. He also went to a 73/84 instead of the 76/86. This took me down in the 60ft but also down in the mph. The car has gone as high as 112 with this setup,But i also understand it may have been spinning causing the higher mph. They have beenout of town the last few weeks so i have been on my own. He said to go up in jets and try to pick up the mph. Also they dont even run power valves front back they just square up.

 

I don't understand how you checked piston to valve clearance with the clay.

You say you adjusted to zero lash plus 3/4 turn but it's a solid roller.

Did you rotate the crank 2 revolutions? The valves are never open when the piston is at TDC. Clearance is at minimal as the valves are opening and closing and the piston is below TDC.

 

I also noticed the Hughes converter...I have no personal experience, but I have two friends that had high stall converters from Hughes and they were both junk. Maybe you have a ton of slip at the top end?

What RPM are you shifting at and what RPM are you crossing the line at? With that cam, I assume it will be in the 7000RPM range.

 

Absolutely needs compression with that cam!!! you do not have a chamber CC listed?? gasket thickness?? stock or zero deck?? I would run 11-11.5 compression... your MPH & times are terrible for a stroker engine... even my HSR 357 was pulling 113 MPH launching from 2nd gear @ 2 - 2.5K
that cam might be a lil much... base timing is @ ??
from what you list you should be out of the 11's

 

Pretty much what I told him in the PM. I think 260/270 would be better suited in a 13.1 motor with 2 inch headers, 227 heads and a 5500 stall converter.

the loss of top end MPH is another major problem that needs to be sorted out. An 11.50 is probaby doable but I bet the car could be faster a little more sorted out.

 

you got street car exhaust on a racecar engine

and too much camshaft for the compression. you'd be really happy with something in the bottom 25x* range on the camshaft.

 

The clay was used to check how much space they is with the valve opened at 0 lash. If you can have good clearnce at 0 when you set the lash at .25 you will have plenty of space. It may sound dumb but this is the way we have always done it and it works. The valve will leave a mark in the clay and you can cut that clay with a razor and mic how far down it comes. i always check more than the running lash to be safe.

The piston is a flat top 5cc relief,
70cc head
.041 head gasket

I can shift the car at 6500 and it will cross at 6500
i can shift at 7000 and it will cross just at 7000
seems to fall off at 6500

I know the exhuast is not the best maybe i need to run the big headers and try to fit in duals

The timing is at 39 Have not really messed with it much it is locked out. If i go less it falls into the 12s

 

Those 275 tires are probably around 28" diameter...so you are getting converter slip of around 9% (6500RPM, 4.30 gear and 109MPH). That's a little high.

Your compression (assuming zero deck height) is going to be right around 10.2:1. That's pretty low for that cam.

Again, all of the points above are valid. Still doesn't explain the 91MPH in the 1/8th and only 109MPH in the 1/4.

If it were my car, I would immediately dump those headers and throw on a set of 1 3/4" primary headers. Plenty of cheap sets out there floating around.

 

I think the exhuast does need to be changed and will look into that for my winter project.
It looks like i may luck out and get some help tommrow if we dont get rain.My buddy is going to be in home friday since they have no race this weekend he seems to think car needs to come down on jet. So he is going to tune the car friday night for me at the track. Since this is what he does for a living i trust he can get some more out of it.Keep your fingers crossed. Hopefully i can get down some more and do exhuast in the winter

 

i think you'll be chasing your tail till you get a real exhaust system on the car. there is alot of power to be had in a well thought out system, and alot of power to be lost in a garbage system. i also feel that you'll get it a bit better, but the long and the short of it is, you'll not get it optimized as long as you have that huge cam, and no compression. either up the compression some how, or go to a better matched camshaft.

 

I think the cheap way is the cam shaft change and exhuast, Will long tubes and 3,5 do it or is it going to need true duals? The money tree is gone till winter since i just did the 9inch swap,lol

 

i think you'd be cheaper to do 2.5" or 3" duals than to try to do a big single. those are expensive.

 

I ran my times through 2 open cutouts. I also ran pretty much within a tenth or so through my dual exhaust. It was 2 straight (2.5 inch) pipes into 2 old flowmasters and out to the rear bumper.

The biggest thing is getting some hooker long tubes on there and run a set of pipes that will breathe. If the car is running right it will run good through any exhaust combo.

 

Im going to start looking for some long tubes. It sucks becouse i just put about 600.00 into this setup with the supercomp 1 5/8 and then had them coated. Hopefully i can find a set for a good deal and have them coated here.

 

Money goes nowhere!

 

Yep. Exhaust, take 10 deg out of that cam, maybe widen the lsa out to 108-110, and retune. Should wake up. With better exhaust might beable to go with tighter duration split, maybe 4-6 deg instead of 10

 

i have almost the same setup and run an 850 carb and 1 3/4 long tubes. i also have around 12 to 1 compression and the car goes 10.90s, unless you are turning over 7k which i heard 383's dont like. i think a 950 carb is too big. quick fuel told me to use an 850 and it's worked great.

 

Why would a 383 not like going over 7k? The rpm limits of any engine depends on the quality of the parts used and the weight of the rotating assembly, not the displacement or bore/stroke combination.

I was spinning my 540 BBC to 7600 rpm but could have taken it higher. The cam grind set the limits however I did produce more power than what the components could handle and eventually snapped a rod bolt.

 

Well Just a quick update,First removing the sway bar did help in weight transfer the car picked the left front tire up about 6 inches off the ground. We started jetting down since some plugs looked wet with gas. That made the times worse the car liked more jet even though the plugs said otherwise. Before the end of the night we had the car running 112mph et dropeed to 11.71 had one pass at 116 but the et was bad 12.0 guessing the car was spinning.
Well the next morning when i went to unload the car i seen oil on the trailer. Turns out i had a seal leaking behind the balancer. So i pulled the balancer while reinstalling the belts i hit the timing pointer and seen it move. The pointer has been lose since its adjustable,I went back and rechecked the timing marks. I set the motor at tdc and the mark was on 5degrees. So the whole time i have been running the car at 37 its really been at 32.
I have not been back to the track trying for this friday. I currently am installing the battery in the back,installing a 2 step and line lock. Hopefully a little more timing will bring me down some on my et.

Thanks to everyone for the help so far.

 

similar thing happened to me. I was driving the car on the steet a lot and always felt like the car was slowing down. I took a friend for a ride and we both agreed it felt like a turd. I reached under and the bolt on the distributor was loose and the distributor was totally out. I replaced it with a stud.

I also was running 11.0's like a bracket car. My balancer was black with a blue timing mark where I set the timing to. I never really new where that mark actually was because my engine guy put it there. I ran some MSD timing tape across it and realized it was at 34' timing the whole time. I moved it up to 38' and the car picked up .3 and 2mph.

 

I hope i can get the car back in the track friday. It would be great to see 11.50 this year. I would think it should pick up if i bump the timing up to at least 38degrees . All i can is try!

 

I have ordered the hooker super comp full tube headers. I am looking at the comp cams
288ar-6 anyone else you this cam or have a comment on it before i buy it?

 

i'm liking the looks of that cam. should have a fat mid-range and will likely pull well beyond the advertized 6200 rpm.

 

I'm hope it will show a drop in et, Its cheaper and alot less work then swapping pistons!

 

Hey guys I'm looking at one more cam from lunati I don't habe the exact grind number with me as I'm out of town. Maybe fast 383 can post the grind number if he see's this post.
I think the numbers where 288/296 advertised and 255/263 @50.
I'm going to be back home later tonight and want to get a cam ordered. I only plan on changing the cam and putting the long tube headers on with some dual dumped on the axle. Please chime in and say what you think on this and the comp cam. Also If you Think its not going to make a diffrence say so. My feelings will not be hurt.

 

Just a quick observation. While I agree with the previous postings of matching cam to compression and improving the exhaust (And don't just try open collectors with NO extensions) I noticed the very small air filter you're running.
If you go through the K & N catalog they have a table listing the square inch of filter media needed per rpm/cubic inch. You will find that you're very much on the small side. This will mess up you AFRs especially at the top end when the engine is working the hardest.
Don't laugh. It's true. (And don't race without a filter)

 

I plan on running 2.5 or 3 duals into race bullets seen some good pics from a few members. Also that was a old pick filter I have a big filter on it now .I have also done the no filter at the track,lol thanks for the tips I can use any advise.

 

I'm surprised at how many guys race with undersized filters or poor exhaust and they all say "Well, I'm making xxx hp and go this fast so I don't think it's a problem".
My only comment is " Consider how much MORE power you can make and how much FASTER you could be with simple applied engine theory".
You sound like you're on the right track with your proposed mods.
Match the cam to the compression ratio and provide a decent exhaust and you should see significant improvement.
Two of the best articles on the above subjects (if you haven't read them already):
http://www.empirenet.com/pkelley2/DynamicCR.html
http://www.superchevy.com/technical/...h/viewall.html

 

Thanks I will read up on the links once I get back home today. I'm getting ready to hit the rode from Pennsylvania back to Virginia. I just need to decide which cam to buy. I'm hoping to have it switched out for this Friday nights testntune.
Thanks

 

LUN-501C1LUN or 288ar-6 comp cam here are both cams im looking at

 

Run the lunati but I still dont think you need to go quite that big to make power. With the stall and gearing, i think it would like no more than 250 deg on intake

 

Well i placed my order with summit i bought the comp cam here are the complete specs

SpecificationsIntakeExhaustRPM Range:Valve Lash:Valve Timinguration:Lobe Separation: Duration @ .050" Lift:Intake Centerline:Valve Lift:Lobe Lift:Valve Timing @ 0.02 Lift:
Drag Race, 288AR-6
Baseline Short Track Cam, Heavy Cars and Small Engines
MECHANICAL ROLLER-Baseline short trackcam. Heavy cars and small engines
Great torque, 10:1 compression, 3500+ stall
RPM Range: 3,500 to 6,900 rpm

Part Number12-900-9 Engine1955-1998 Chevrolet
262ci-400ci
8cyl. Grind Number CS 288A-R6 DescriptionIntakeExhaustValve Adjustment0.02 0.022 Gross Valve Lift0.63 0.63 Duration At 0.02 Tappet Lift288 296 Valve Timing At 0.02 OpenCloseIntake38 70 Exhaust74 42 These Specs Are For The Cam Installed At 106 Intake CLIntakeExhaustDuration At 0.05 252 258 Lobe Lift0.42 0.42 Lobe Separation106

































Im going to start pulling the other cam out monday should have the new cam on wed/thur. hoping to go friday night for test and tune. Wish me luck i will keep you posted on what happens

 

Keep us posted. There's blood on my hands from this one. lol

 

i will let you slide till i change the exhuast i going to run with the current headers this friday till winter. To do the true 2.5 or 3 inch exhuast to the axle with bullets and dump i need to have my turbo 350 cross member modified a bit and i really want to try the new cam this week. When its all done if its still over 11.50 i will say its all your fault,lol

 

well everyting is out waiting for new cam to get here today, Im sure ups will take his time since im in a hurry,lol

 

New cam is in and degreed, Just need to finish the top end intake, Set the valves,Wires and hoses, Should be done tonight, So i can make the Friday test and tune

 

nice progress. very interested in how it does. too bad you got no time for the header install

 

Well its running,Feels weak on the street. I hope its gets better at the track. Feels like its down on tq. But we will see tommrow night

 

Looked up the cam info again, My cam card says intake .20 exhuast .22
Online comp cams says intake .26 exhuast .28 So i guess in the morning i need to see what the valves should be set at. Looks like my cam card may be wrong everywhere is saying 26/28

 

Wern't we were hoping to gain TQ? Lets see how it works out at the track. MAke sure your launching hard.

 

Yes we where looking to gain, It does not pull hard like it did before. Not sure whats going on. I need to call comp cams when they open and check on the valve lash. It does not even seem like its worth going to the track as it is now.

 

Distributor in right? Timing at 38*? Running all 8 cylinders? Plug wires crossed?

 

Yea its all straight, I took it back out a drove it a little harder. the rode was wet last night and it was dark so i never took it over 6200. My old cam liked 6200 shifts this seems to like more around 7k. wont really know till i go to the track. Been having rain showers this morning hopefully it clears in the afternoon.