Would like to get some more oomph from my 318

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jrc4y4

jrc4y4

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Hi guys, I have a 72 Scamp. It's got a 318, bored .030 with KB hyper pistons (~9:1), .454 lift 236* duration Comp cam, Edelbrock Performer intake, Edelbrock 600 carb, 904 trans with a shift kit and 2800 stall, and a 7.25 rear with 2.76 gears. It ran 15.22 with the setup prior to the trans rebuild and stall and ran 15.30s-40s last time out with the stall. Dyno'd 200 HP and 240 TQ as well.

I plan on putting in an 8.25 with 3.55 gears as I drive it on the street 99% of the time but want some more launch as it falls on its face currently (2.38 60 foot time with no tire slippage) when I do make it to the track. I would LOVE to hit a 13.9X with a 318 without doing anything else to the bottom if at all possible. If it's not an attainable goal, oh well, I would be happy in the 14s with a 318. Just like #s matching.

With that said, I can buy a set of 302 heads for $250 already rebuilt, or I have a free set of 3671587 heads that are bare. I was planning roller rockers while doing the heads and switching to electric fan as well.

The car has the stock manifolds on it and it has power steering that I am keeping on. Would the hi performance manifolds from a 340 be a good option or is there a header I can fit without crazy modification? I'm just starting to look around at some stuff I can do and planning my long term course. Doing the rear end hopefully this winter. Any input would be great. I really don't want to go crazy with anything, just seeing a few things come up in my budget is all. Thanks.
 
Get the low first gear set for the 904. An H or X pipe will also improve the low end if you don't have one. Also check the advance curve settings for a good gain.
 
jrc4y4 said:
I plan on putting in an 8.25 with 3.55 gears as I drive it on the street 99% of the time but want some more launch as it falls on its face currently
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I would do this first, before moving any further. That gear change will make a huge difference.

Headers might give you a bit more, TTI's or Dougs fit better than the rest, but dig into the wallet a bit more. Watch Autozone when they have them on sale, get Summit to price match and you get free shipping.
 
Gears and axle first. I would build the 587 heads as they will outflow the 302's, however you will need a taller piston to counter the larger chambers otherwise you'll lower your static compression. Headers then will compliment the combination further. Just gets more expensive though
 
Second on those TTI's but to conserve your wallet for that rear-end, Hedman shorties will do you pretty well
 
Smaller tires. :D
Cheapest fastest way to lower gearing.

Of course you still want to do the other stuff, but that'd make a difference right now.
 
Timing FIRST!!! What are the initial and total numbers.

Ede Carbs are notouriosly lean everywhere in the curve.
 
Headers, gears and low 1st gear are all good mods, unless you plan to port the 302 heads I'd go with EQ'S or someother magnum type head.
 
did you say budget? home port your own heads.... that will get ya into the 14's from your 15.22 for cheap....
 

mguner said:
Get the low first gear set for the 904. An H or X pipe will also improve the low end if you don't have one. Also check the advance curve settings for a good gain.
Click to expand...

Like this? Low-Gear Sets - A&A Transmissions
Cool, I had never heard of that! Wish I had known when I rebuilt the trans.

I do not have an H or X pipe, just 2.25 inch exhaust.
 
fnaramore said:
Second on those TTI's but to conserve your wallet for that rear-end, Hedman shorties will do you pretty well
Click to expand...

Hedman shorty headers won't interfere with my steering box? Happen to have a specific part# or thread on the same?
 
TrailBeast said:
Smaller tires. :D
Cheapest fastest way to lower gearing.

Of course you still want to do the other stuff, but that'd make a difference right now.
Click to expand...

I actually am buying tires soon. Not sure I want lower profile tires as I have 14s.

Scamp2.jpg
 
crackedback said:
Timing FIRST!!! What are the initial and total numbers.

Ede Carbs are notouriosly lean everywhere in the curve.
Click to expand...

Not sure. I think my distributor is a tooth off. I am running without vacuum advance. Was gonna have a buddy help me time and tune it soon as I'm not the most versed on these things.

Is there a way to combat the leanness?
 
273 said:
Headers, gears and low 1st gear are all good mods, unless you plan to port the 302 heads I'd go with EQ'S or someother magnum type head.
Click to expand...

What are EQ? Do magnum heads directly fit? I would rather not port anything. That's past my area of expertise.
 
Ok so it seems the general consensus is to definitely do the gears first and possibly the headers without doing any head work. Is that what you guys are saying?
 
jrc4y4 said:



Like this? Low-Gear Sets - A&A Transmissions
Cool, I had never heard of that! Wish I had known when I rebuilt the trans.

I do not have an H or X pipe, just 2.25 inch exhaust.
Click to expand...
Yes that is the gear set. Conspicuous by its welded 4 gear planet setup and dual size sun gear. I have found in many cars the H or X pipe was the difference between and average take off and blowing the tires off. It can make that much difference. Not every car responds the same but it almost always helps.
 
This is what my car looks like now in case anyone was curious :). As you can see it's not a race car. I would just like it to be faster and be able to hang out with some quicker cars.

ScampMotor1.jpg


Scamp1.jpg


Scamp2.jpg
 
mguner said:
Yes that is the gear set. Conspicuous by its welded 4 gear planet setup and dual size sun gear. I have found in many cars the H or X pipe was the difference between and average take off and blowing the tires off. It can make that much difference. Not every car responds the same but it almost always helps.
Click to expand...


So do the gear set in the trans and the rear end you think? I would be hiring someone to do the trans stuff as I do not touch those things lol. And it keeps the 1:1 final ratio so my cruising RPM is the same? Right now when I trap I'm at the point where I need to shift into the final gear. Sometimes I do sometimes I don't.

Ok I will do an X pipe. Should be cheap at an exhaust place. Thank you.
 
Yes the final ratio in 3rd will not change with the low gear planetary in the transmission. It only lowers 1st and 2nd gear giving you a little bit harder launch. That and with the 8.25 axle with 3.55:1 gears will change the whole feel of the car. Do the gears and axle first and you may be happy enough with the results and leave the rest of the motor alone. Till the speed bug sets in again and you want to go faster in the future of course!
 
The cheap headers are a pain and take a lot of the fun out of driving.
 
One quick thing that would help is to get a taller air filter, remember, carbs mainly pull air from the sides so the filter top isn't adding too much, though I do have one myself haha I don't have a part number but if you just go on Summit Racing, put in your car info and search headers they will come up. Just be prepared that they most likely will NOT line up with where your manifold collectors are, will have to do a bit of exhaust routing. Iv never had an issue with Eddy carbs running lean but your first step there would be changing the metering rods to richen it out a bit
 
jrc4y4 said:
I'm hesitant to do any of my own porting to be honest.
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1st, Nice looking car!!! Now on porting the heads, if you visit my "low dollar 318 build" in the small block section, I have a video that explains how to home port heads. Several here have followed it and it's made it easy for them.
 
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