Seems a little slow...

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73Scamp318

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Location
Waterloo/Cedar Falls - IA
I've been duking it out with this car ever since I built the 318 for it and it just doesn't seem to perform as well as I think it should. I'm ripping my hair out and am about ready to sell it off. Please give me some ideas as far as what to look for or if what I think it should run is way off.

I'm thinking this thing should click off at least mid- to low-13s all day long.

The engine:
318 .030 over, KB399 pistons, Eagle SIR rods, forged crank, windage tray
J heads, 2.02/1.60 valves, well ported by Aerohead, 1 5/8 Hedman headers
Comp 282 solid cam, 236* @ .050", .528" lift with Hughes 1.6 rockers
Weiand Action Plus intake, port matched, 750HP Holley DP, 1" 4-hole spacer
viscous fan, belt driven water pump and power steering
Mallory 110 electric fuel pump, stock tank, 1/2" line in the tank all the way to the carb, non-return

The drivetrain:
stock 727, TCI valve body, with PTC 9.5" converter, brake stalls at 35-3600
3.91 with sure grip, 235/60-14 M&H Muscle Car D.O.T. Drag Tires, about 25-26" tall...all I could find for 14" rims

Chassis:
SS leaf springs, pinion snubber, no frame connectors
weighs 3600 with a full tank and me in the seat

Best run:
60: 2.079
330: 5.794
1/8: 8.819
MPH: 81.78
1000: 11.442
1/4: 13.657
MPH: 102.05

This run was with a Victor 340 with the same 750 Holley and the 60' is typcial. I've never seen a 60' time below 1.95 and the tires don't spin. Fuel pressure is set at 6.5 psi and it holds above 5 psi through the traps.

It may also be worth noting that I've run this car with 4.88 gears before. It ran about the same with no noticable change in any of the times or MPH and didn't touch the rev limiter, which is set at 7200.

I took it to the track last weekend after throwing the dual plane on it and the best I could get out of it was a 13.8 @ 98 mph with open pipes.

I was talking with my dad about it, he thinks it may be a fuel problem or the converter's bad. At this point, I don't want to throw any more money at it without a decent plan. Help!
 
I had a 318 built close to what you have and when I un hooked the exhaust and ran open headers I lost almost a 1/2 a second I went from 8:10 to 8:50 1/8 mile back in the day. Just a thought
 
On my last trip to the track, I dropped the pipes. Pretty sure I picked up .15 and about 1 mph to put me at 13.8. I don't have the time slips in front of me at the moment, but I can take a look later today to see what it was.
 
It all sounds pretty good except one thing caught my eye. 1 5/8" primary tubes. Those are not for racing. Those are street headers. Period. you put a 1 7/8" primary tube on that thing and it'll pick up. BUT......it's really not runnin bad like it is. If it was me, I'd be happy with it. IF I wanted to look to speed it up, the headers would be the first place I would look. Just remember when you get into doing this, do your changes one at a time. Because if throw more than one change at it and it goes the other way, it'll be tougher to figure out. Lastly, to get the most out of big tubes, you'll likely need to do some super tunin on it. Maybe jet the carb up and perhaps play with the timing as all these things are connected. Oh yeah....and go back to the Victor.
 
I'd put some frame connecters on before you start to buckle the body in front of the rear tires. Might even help you pick up some ET. If you'd like some help let me know I'm from waterloo. Good Luck! Tom
 
Maybe the aerohead heads are leaking or poorly ported, i have not heard anything positive about aeroheads work. the car might go much faster with a smaller cam IE.. more cyl psi for better low end = faster 60' I would try a cam swap if the heads are ok to something in the 220 to 226 @.050 with a 475 to 500 lift. your times don't seem to far off, but 60' is bad
 
The 1 5/8 headers are what I have to work with at the moment. I'd love to get a set of TTIs or Super Comps, but I just can't bring myself to spend $500 to $700 on headers at this time.

Frame connectors would be a logical next step, but I'm looking to get out of this chassis at the end of the year.

I've checked the compression with all the plugs out, 155 to 165 in all the holes. I hadn't thought too much about cam swap.
 
I wish i had your car set up.
That's a great combination and i wouldn't change anything.
First things first.
Your short time is way off.
The two things that control that are your timing and carb.
What distributor are you running and what is the total timimg set at.
ALSO>>>does it have the total timing in by 2500 rpm's.
You want to be at full advance before it hit's the converter so it will give you the fastest 60 foot posible.
Your carb needs a bigger shot of fuel,so change your pump shots to a bigger size.
Set your carb up like this.
71 jets \\ front
81 jets \\ rear
35 pump shot front and rear
pink cam set up.use hole #1 hole on carb and use the # 2 hole on the cam and set the arm under the front excelerater pump for the right amount of lash.A little looser then you would think.
I will have to check my holleys but i think it's about 5 thousands space.
The back pumps(secondary's) lass is a little tighter and adjusted to zero.
lash.
Don't change anything other then the intake \\ use the victor intake.
Try to use this set up even before you change the intake back to the victor so you can see the difference.
The only problem i see with your parts selection is the 1.6 rockers.
Your lifting the valve way higher then the heads will flow i would think.
Did you get the heads flowed on a bench?????
If you did post the flow #'s.
Good luck.
I think your car will pick up at least 4 tenths or more.
That set up should go high twelves tuned in.
What sea level is your track at?????????????
 
What rpm is it turning at the stripe now with the 3.91s? And answer T67s question on timing/distributor. I think you're down on horsepower if it's only pulling 102. I'd be expecting high 12s, maybe more with the 4.88s.
 
T67POWER said:
I wish i had your car set up.
That's a great combination and i wouldn't change anything.
Click to expand...

Thanks :) It's good to hear that it's not completely screwed up.

T67POWER said:
First things first.
Your short time is way off.
The two things that control that are your timing and carb.
What distributor are you running and what is the total timimg set at.
ALSO>>>does it have the total timing in by 2500 rpm's.
You want to be at full advance before it hit's the converter so it will give you the fastest 60 foot posible.
Your carb needs more a bigger shot of fuel,so change your pump shots to a bigger size.
Set your carb up like this.
71 jets \\ front
81 jets \\ rear
35 pump shot front and rear
pink cam set up.use hole #1 hole on carb and use the # 2 hole on the cam and set the arm under the front excelerater pump for the right amount of lash.A little looser then you would think.
In will have to check my holleys but i think it's about 5 thousands space.
The back pumps(secondary's) lass is a little tighter and adjusted to zero.
lash.
Click to expand...

The distributor is one of the newer Mopar Performance units with the Mallory guts. This thing likes a lot of base timing. I've had the initial up to 36 degrees without it kicking back or making the starter labor turning it over hot. I backed it off to 22 degrees initial and am running 36 degrees total, all in by 2500.

The jets are at 72 front and 84 rear, which is where the engine seems to like it. Going up or down slowed it down, but I'd be willing to give it a try. I'm running the green cams in the #1 holes, front and rear, with a 25 squirter in the front and a 31 in the rear. I'll try the cam and squirter changes and try adding a little play in the front pump arm.

T67POWER said:
Don't change anything other then the intake \\ use the victor intake.
Try to use this set up even before you change the intake back to the victor so you can see the difference.
Click to expand...

I just got it changed over after porting the manifold, but I can't really argue that the numbers weren't better with the Victor.

T67POWER said:
The only problem i see with your parts selection is the 1.6 rockers.
Your lifting the valve way higher then the heads will flow i would think.
Click to expand...

The lift is figured before the lash...did I mention that this is a solid cam? I thought I did, maybe not... Anyway, after the valve lash, lift should be around .506".

T67POWER said:
Did you get the heads flowed on a bench?????
If you did post the flow #'s.
Click to expand...

I wish I had...no numbers available.

T67POWER said:
Good luck.
I think your car will pick up at least 4 tenths or more.
That set up should go high twelves tuned in.
What sea level is your track at?????????????
Click to expand...

I'd really like to see those low-13s or high-12s.

The track is at 850' and the air has been really crappy lately. The current DA is 3121', but it's probably under 2500' during the summer around here.
 
Another thing that I thought of that may be worth mentioning, the KB399s are dome pistons and the heads are open chamber. I read somewhere that dome pistons like more timing as a general rule, as do open chamber heads. Can anyone verify this?
 
I know all about budget and things are all to often "use what ya got", but I believe the 727 is hurting you're et.

A couple of people I know switched from the 727 to the 904 and in the eighth mile they lost 3 tenths. It is noted that a 904 will take up around 25hp to turn as to where a 727 will take close to 50hp to operate. A 727 is good, but these are just observations through trial and error. My friend went to a 727 and it killed the bottom end on his 318. Is the TCI valve body a full reverse manual?

The rest of the combo looks real good IMO.
 
Yeah, I should have gone with a 904 over the 727. Next time around maybe, but for now, it's what I have. I'm pretty sure the valve body is a Street Fighter, it's not a full manual.
 
I too think your doing very well, I don't see why 1.5/8" headers would be too small for a 318, sorry but i disagree on this 100%, this size primary is more then enough for what you have, But there is 1 thing i would change, thats the carb, bigger is not always better, that 318 would run stronger & 60ft. better with a 650dp, & the 60fts. are very weak, it should be in the low 1.8s @ bare minimum, thats a solid 3 tenths right there, your MPH is really good at 102+, thats 13.0s all day long with the right 60ft., theres a good .5 in that car, you just need to find it. my 2 cents!!
 
Your pump shots are way too small.
35 front and rear too start.
Wait until you hit the gas.
It will be a hole new car.
Every tenth you gain in 60 foot adds up to about two tenths at the end of the track.
If you can gain two tenths 60 foot, then you should have four tenths on the top end.
The 1 5/8 header is perfect for your motor.
The 727 will slow you down a little bit but on the other hand it's very strong.
The 904 has a lower gear and is faster off the line.
The reason i said the 1.6 rocker was over kill was that your lift will be around
.563 - your lash setting.
Going off your post you use a .026 lash setting and that comes out to .537 lift.
It really isn't a big deal, but if you had the heads flowed you would know where your cut off point would be and run the lift up to that point + the amount the lash.
What's the lsa for that cam?? (center line)
 
T67POWER said:
Your pump shots are way too small.
35 front and rear too start.
Wait until you hit the gas.
It will be a hole new car.
Every tenth you gain in 60 foot adds up to about two tenths at the end of the track.
If you can gain two tenths 60 foot, then you should have four tenths on the top end.
The 1 5/8 header is perfect for your motor.
The 727 will slow you down a little bit but on the other hand it's very strong.
The 904 has a lower gear and is faster off the line.
The reason i said the 1.6 rocker was over kill was that your lift will be around
.563 - your lash setting.
Going off your post you use a .026 lash setting and that comes out to .537 lift.
It really isn't a big deal, but if you had the heads flowed you would know where your cut off point would be and run the lift up to that point + the amount the lash.
What's the lsa for that cam?? (center line)
Click to expand...

I'll definitely try the pump shot changes. I have a full range of nozzles from 25 to 42, so I'll start at 35s and do some experimenting.

I guess I should have said that the .528" lift is calculated with the 1.6 rockers. Lift with 1.5 is .495".
 
I have to agree with Joedust451. 1 5/8 headers is a perfect size. I am surprised you think its slow, I know that I am quite impressed. Although, I see some short comings that you can correct and make it faster. First off like most of the replies here, your 60 foot is off and you will et much better with a great 60 foot. Like Joedust451 I think the 650DP may be better suited to your combo since its cubically challenged. The 60's might improve going with a smaller carb but it may trade off some mph. I would be willing to bet it would pick up all around since your mph is low indicating your hp. I am a BIG proponent of the 904, I have done the change twice and both times I picked up .5 and 6 mph with the change which would make you a 13-oh car. I would also be suspicious about the converter, I think you stated you are running a 10 inch that stalls 35-36 hundred. This stall is really high for a short stroke 318. I think tightening up the converter will push your mph up a lot but wont help the 60 foot unless its slipping so bad that you aren't utilizing the torque peak. The original combo you ran sounds like a well thought out combo and I would look elsewhere for your ET. The problem with 3.31 stroke combo is torque, or lack thereof. I ran a 273 that had similar problems, but I was able to get it roight although the converter company was local and they reset the stall like 5 times to get it right. Once it was right it worked great! Good luck!
 
my old 360 dart with a little hotter setup than yours ran 13.3 @99Mph so your #`s seem about right
 
turbodart68 said:
I am surprised you think its slow, I know that I am quite impressed. Although, I see some short comings that you can correct and make it faster. First off like most of the replies here, your 60 foot is off and you will et much better with a great 60 foot. Like Joedust451 I think the 650DP may be better suited to your combo since its cubically challenged. The 60's might improve going with a smaller carb but it may trade off some mph. I would be willing to bet it would pick up all around since your mph is low indicating your hp.
Click to expand...

I happen to have a 650DP sitting on the shelf, maybe it's time to dust it off.

turbodart68 said:
I am a BIG proponent of the 904, I have done the change twice and both times I picked up .5 and 6 mph with the change which would make you a 13-oh car. I would also be suspicious about the converter, I think you stated you are running a 10 inch that stalls 35-36 hundred. This stall is really high for a short stroke 318. I think tightening up the converter will push your mph up a lot but wont help the 60 foot unless its slipping so bad that you aren't utilizing the torque peak. The original combo you ran sounds like a well thought out combo and I would look elsewhere for your ET. The problem with 3.31 stroke combo is torque, or lack thereof. I ran a 273 that had similar problems, but I was able to get it right although the converter company was local and they reset the stall like 5 times to get it right. Once it was right it worked great! Good luck!
Click to expand...

3600 is the absolute max I can run it up in 1st before it overcomes my ability to hold the brakes. I'd like to go to a 904 at some point. I do know someone that's in the market for a 727 converter, but I think it'd be all wrong for his 440 and I wouldn't want to sell it since it may not be working right.
 
ligthen the car every 100 lbs. is a .10, 3600 is alot for a small engine
 
Dust off that 650dp, trust me!! Start off with the stock jetting & squirters.
 
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