Exhaust Manifolds

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Yeah, superchargers sure are lame

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Mean416 said:
Yeah, superchargers sure are lame
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Who cares, that looks like it would work for a cross country jaunt. Spend 12 hours driving that down the road, if it would last that long. If you can't make a car fast without a supercharger or turbo, I guess go for it.
 
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Lots of people care, because no amount of mastery and badassness of NA build will bridge the gap between that and a forced induction build.

I love NA builds, boosted builds, stock builds, sleepers etc.
 
Wow, from a street drive 318 question to a picture of a top fuel car in less than 5 pages. Has to be a record. For the original post manifolds would be fine. If the build progresses, headers. With all that in mind, you can go quick enough to require a bar with manifolds.
 
toolmanmike said:
I'm surprised no one has mentioned that a funny car cage is needed. :rofl:
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Only at a sanctioned drag strip, which is becoming a dying breed. Headers for me. I bought a set of Appliance headers back around 1978 and used them until three years ago. They were a little thicker than most other brands and I painted then every two to three years to keep the fresh. I noticed a big difference from the stock manifolds. Appliance is no longer around, so my suggestion is buy the best you can find and take care of them, and they should last. You get what you pay for.
 
toolmanmike said:
I'm surprised no one has mentioned that a funny car cage is needed. :rofl:
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One of my best friends is like that. He could not build a street car to save his life, it always turns into a race car that needs to be trailered everywhere. I told him we should run part of Route 66 some summer, and he looked at me like I was crazy.
 
66fs said:
One of my best friends is like that. He could not build a street car to save his life, it always turns into a race car that needs to be trailered everywhere. I told him we should run part of Route 66 some summer, and he looked at me like I was crazy.
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Yep, over built, over powered, over done.
 
Swinger 340 said:
Only at a sanctioned drag strip, which is becoming a dying breed. Headers for me. I bought a set of Appliance headers back around 1978 and used them until three years ago. They were a little thicker than most other brands and I painted then every two to three years to keep the fresh. I noticed a big difference from the stock manifolds. Appliance is no longer around, so my suggestion is buy the best you can find and take care of them, and they should last. You get what you pay for.
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I sold them back then. Ton's of them. They were quality built, reasonably priced, and great for the street. The race guys usually ran Hookers because they had bigger tubes available. Not needed on the street.
 
furrystump said:
Wow, from a street drive 318 question to a picture of a top fuel car in less than 5 pages. Has to be a record. For the original post manifolds would be fine. If the build progresses, headers. With all that in mind, you can go quick enough to require a bar with manifolds.
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Sweet, do I get a prize?

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I know that this has been discussed before but why do some people recommend the 360 truck manifolds for the A body small block when they won't fit. I think that it's been said that the right side fits but not the left and for that the 340 manifolds have been suggested but they are hard to find. What about manifolds from the volare / Aspen that had the 360 or a diplomat,etc. Was there a police interceptor 360?
 
Dan the man said:
I know that this has been discussed before but why do some people recommend the 360 truck manifolds for the A body small block when they won't fit. I think that it's been said that the right side fits but not the left and for that the 340 manifolds have been suggested but they are hard to find. What about manifolds from the volare / Aspen that had the 360 or a diplomat,etc. Was there a police interceptor 360?
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IMHO you are always better to use the best manifolds for the car you have. There is a reason they were made specific for your car. Generally the older the better, exhaust manifolds got pretty ridiculous as time went on. You can buy ready to go exhaust and use factory tips and hangers. Otherwise you are reinventing the wheel all the time, and for what gain? All that time and finagling for a small gain, I just don't see the point. Or just spend the money and get custom.
 
Dan the man said:
I know that this has been discussed before but why do some people recommend the 360 truck manifolds for the A body small block when they won't fit. I think that it's been said that the right side fits but not the left and for that the 340 manifolds have been suggested but they are hard to find. What about manifolds from the volare / Aspen that had the 360 or a diplomat,etc. Was there a police interceptor 360?
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1- the truck manifolds are recommended for narrow bodies because they fit the cramped engine bay and are cheap and widely available.

2- the DS is always going to be problematic because of the seemingly endless array of possible combinations: early, late, manual, column, 360, 318, [brand] heads. beyond bone stock it is nearly application specific. but if you have the time, money and inclination to test fit a bunch of different manifolds, you could probably find something that works.

3- 340 manifolds are NOT hard to find. i don't know why you keep insisting on pushing this fallacy. look, dan, right now, right here, on this forum's very own classifieds there is a set: [FOR SALE] - 68-70 A-Body 340 HP Exhaust Manifolds $550

4- what about [blank] manifolds? i suggest you go back and re-read section 2 from above.

5- yes, there was a police package 360. it did not have special manifolds. and if it did, it would be unlikely for the DS to fit because they came in 80's cars that have transverse t-bar suspension, isolated k-frame and column shift.

so, we are back to our usual starting points, which i will list for those of you still following along:
1- get a car first
2- worry about stuff later
3- you aren't going to make enough power for anything beyond dual exhaust to matter.
 
I think his,warmed over 318 requires the car to be mini tubbed, shortened Dana 60, and a 4 link set up
 
junkyardhero said:
1- the truck manifolds are recommended for narrow bodies because they fit the cramped engine bay and are cheap and widely available.

2- the DS is always going to be problematic because of the seemingly endless array of possible combinations: early, late, manual, column, 360, 318, [brand] heads. beyond bone stock it is nearly application specific. but if you have the time, money and inclination to test fit a bunch of different manifolds, you could probably find something that works.

3- 340 manifolds are NOT hard to find. i don't know why you keep insisting on pushing this fallacy. look, dan, right now, right here, on this forum's very own classifieds there is a set: [FOR SALE] - 68-70 A-Body 340 HP Exhaust Manifolds $550

4- what about [blank] manifolds? i suggest you go back and re-read section 2 from above.

5- yes, there was a police package 360. it did not have special manifolds. and if it did, it would be unlikely for the DS to fit because they came in 80's cars that have transverse t-bar suspension, isolated k-frame and column shift.

so, we are back to our usual starting points, which i will list for those of you still following along:
1- get a car first
2- worry about stuff later
3- you aren't going to make enough power for anything beyond dual exhaust to matter.
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1-3 is correct. With what I'm looking at doing, I think that I'll stay with the factory exhaust manifolds, maybe clean up the opening, run a good, free flowing exhaust system, dual pattern cam. Open air cleaner housing or equivalent. Edelbrock avs2 carburetor, weiand intake with 318 size ports. Factory distributor with curve kit, chrome box. 2.94 - 3.23 gears. If I were to have anything done to the cylinder heads, I'd have a friend of mine clean up the bowl area, seats inspected to see if they need to be replaced if needed. Have a good competition valve job done and have the valve's back cut. Have the chamber side of the heads milled enough to make sure that they are perfectly true. Would this make for a nice combo?
 
yes But
For your combo; Assuming it's still what you talked about so many weeks ago,
Headers
do a couple of things that don't apply to your stated useage.
In no particular order ;
1)They make a little power bulge thru the peak-power band. and if you increase your engines Cam events to take advantage of that effect, it can make a very healthy power bulge . What this means is that from roughly 400 rpm after the power peak to roughly 1500 rpm backwards, quite a bit of power can be created over log manifolds.
Say you had a cam that power peaks around 5000 rpm, the best part of the power could be from 5400, backwards to 3900.
With a regular A904, and 2.76s, 3900 will be near 42 mph in first and near, and 69mph in Second. As you can see, for your application, this is of no use to you. Furthermore the power increase does not happen instantly, but only comes one hp at a time as the rpm increases. Lets say the headers are able to generate 20hp at 5000 over the logs, in your combo. which will be 53 mph.
If One assumes the power increase to be linear, then those 20 hp come at the rate of about 1.8hp per 1 mph Not I big deal in your application.
2) at your power level, using a very modest camshaft, at rpms below say 3900, the headers are going to help very little, except if you have a cam with a lot of overlap, then they are gonna cost you fuel mileage by yanking A/F charge from the plenum, straight over the top of the piston and out the exhaust. So now they are costing you money ALL the time with those 2.76 gears or in fact any gear.
3) At low rpm, in a well-balanced combo, they can create quite a bit of torque over logs, say from stall to ~3000/maybe as high as 3500. But, so will 340 manifolds.

now as to log manifolds.
1) they kill the overlap cycle and that can easily be 30 or more hp with some logs.
2) They may help low-rpm torque over headers, but we're talking torque below stall usually.
3) they are a lot quieter.
4) the fit easy.

now as to the 340 manifolds
1) they still kill the overlap powerbulge, but
2) they have the potential to Breath better than standard logs, at lower rpms , even up to say 4500, I'm guessing. and so, you can run a lil more intake duration.
This can help in your situation.

However, still at your powerlevel, Cylinder pressure will trump power production right from idle to shift-rpm; and if you get your Quench set right, you can even push that envelop. But not just that, along with the higher pressure comes a stronger vacuum signal, which makes the engine more willing to take throttle., and so it becomes snappier.

For your combination however, and from some modest conversation we have had; I'll tell you what I would do , for a hands down winner.
I would slam an overdrive in the tunnel, so I could run a ridiculously low starter gear, and a tight 1-2 split, with a half decently high stall and a Lock-up feature. Then I would stuff anyold decent-pressure engine under the hood with anyold log manifolds, and anyold exhaust, and anyold intake system including a 2bbl.

Say you put a 200R4 in there.
With ratios of 2.78-1.57-1.00-.67od.
To get a cruise rpm of say 2370, with 26.5" tires will require a rear gear of 4.30 and a lock-up. Since you thus have a lock-up, you can run a stall higher than 2370, let's say 2800, this will give you a starter gear, mathematically of 11.95..
say your worn out 318 still make 280 ftlb @2800, That will put
280 x 11.95= 3350 ftlbs into the axles, before even considering what the convertor is doing. So much is available, that I could be inclined to just use whatever convertor comes with the 200R4. Say it's a 2200; and say your anemic 318 makes 260 ftlbs down there, then:
260 x 11.95 is still 3107 before the TC does what it's gonna do. This number has the potential to waste 225/70-14 tires (26.5 tall), thru; the stock iron logs, the stock single exhaust, and the stock 318 cam with the stock 2bbl carb still on it.
Now, those 4.30s are gonna top out at ~26 mph@ 4400 rpm. On the 1-2 shift, the rpm will drop to ~ 2450 or to the convertor stall whichever is higher. This is why, if I had to buy a convertor, I would run at least a 2800, because that 350 rpm could represent a significant increase in delivered torque, and not just in First gear, but especially on the 1-2 shift. And I would run a spread-bore intake like a Thermoquad, if for no other reason than the badazz roar they make when the Secondaries open up.

There is nothing you can do to a normally aspirated 318 that can touch the combination of 4.30s and a 2800 stall, nothing. (unless it's more stall and more gear, lol). And with the overdrive holding the cruise rpm right in the sweet spot of 65= 2370, you can hardly ask for a sweeter combo.
Furthermore, check this out;
Second gear will run from 26 Mph@ 2450, to 4900= 52 mph; which puts 35 mph right at the 318s sweet spot of ~3500 rpm.
Having solved the performance side of the equation; 65@2370 without an overdrive would take 2.88 gears., rounds up to 2.94s.
Lets compare the A904/2.94s, to the 200R4/4.30s in terms of road gears.
..........7.20-4.26-2.94 for the TF and cruises at 65=2500 @3% slip.
11.95-6.75-4.30-2.88 for the Chevy, cruises at 65= 2370 in Loc-up.
Notice anything interesting?
Yes; all the gears in the TF match up pretty nicely with second thru fourth of the 200R4, so what the Chevy trans gives you is just what the 318 lacks, namely, a powerful bottom end.
How much?
Gear-ratio wise, how about 11.95/7.20= plus 66% and that's before considering the convertors.

Considering stall; at zero mph.
If your 318 makes 260 @2200 with a 1.6 ratio in the TC, then that translates to 260 x 1.6 x 7.20= 3370 ftlbs into the rear axles.
If your 318 makes 280 by 2800, and with the greater input, the Chevy stalls at say 1.8 ratio, that translates to
280 x 1.8 x 11.95= 6023 ftlbs.
Lessee ; 6023/3370 = Plus ~78% !!!!!!
That's like making the lowly 318 feel like a much much bigger engine, in first gear.

That's what I would do, and why.
I have already done this except without the overdrive. What I mean is, I have run the 2800/4.30 combo, with the A999, for Road-gears of
11.76-6.62-4.30.
and I can tell you that with nothing but headers and a Thermoquad, my 1973 Smog era 318, was a real hoot. I have to say with headers, cuz the headers were in the car, but that doesn't mean hardly anything in this near-stock combo. She was a lotta fun for a couple of weeks. Then the snow came and I put some winter gears behind her.
 
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