Ratchet

I really dislike headers for all kinds of reasons so I was searching for a good set of exhaust manifolds to put on my 355. Found them in an old GM Power book I had. They came with a kit from GM to install a 350 HO. engine in an 82 to 92 camaro. Here are the part numbers

LH Manifold 14094063
RH Manifold 14094064

The price in the states is 90 dollars each brand new from genuine gm parts you can find it on the web. They will not ship to Canada I checked at the dealer and they can get them but they want $280 Canadian each!!!!!!! !@$!@$!@$!@#$t!

Any suggestions on how I can get a set at a reasonable price in Canada.

Ratchet

Check out Cool link below

Ratchet

Here is a better link it takes you right to the conversion kit.
https://www.spoperformanceparts.com/...119&CATID=1099

88IROC350TPI

Would you mind explaining why you hate headers? Without headers your motor will never work to its potential ...it just makes no sense. You bolt them on, gain power, and make your motor more efficent. Whats there not to like? Its like someone saying "I don't like clean air filters" or something...

Ratchet

Why I don't like Headers.
a short Novel by Me.

They get real hot
Burnt fingers
Burn Arms
Burnt spark plug wires
get loose real fast
Exhaust leaks
Did I mention burnt hands
Rust
Burnt feet in the passenger compartment
Starter don't work once the headers get hot
cant change sparkplugs without being double jointed and having hands the size of a 5 year old.
No room left to work on anything at the sides of the engine without taking the darn things off.
Did I mention burnt arms

What I like about headers.
You can get about 15 more horespower by using them if you are replacing really bad exhaust manifolds.
If you are replacing performance exhaust manifolds like the old rams horn vette one or the ones listed above maybee 5 horsepower.

Did I mention these things get real hot and will burn, melt, incinerate, fricking fry almost anything that gets within 3 inches of them.

All the best
Ric.

Synapsis

And manifolds don't get hot, burn stuff, get loose, leak, etc?

I'd be more worried about the cataytic convertors under their @$$.
Ok, I'll give ya that one.

Ratchet

14.35 @ 97.16 MPH - 2.17 60-Foot with gutted cats & !AC
14.15 @ 97.74 MPH - 2.10 60-Foot with SLP headers/cutout & ported plenum


According to your signature they will shave .2 seconds off of a really good car For the $450 American (about $10,000 cdn.) that is not good enough. And thats provided that the cutout and ported plenum had absolutely no effect on your E.T.

Ric

Synapsis

That's also on a stock engine. Put a cam and intake on your engine and see the difference. I chose my setup based on a 383 buildup I have going right now. I don't want to buy 2 exhaust systems.

Ratchet

So what your saying is that on a stock engine headers don't make enough difference to justify their cost.

Spending your money on a three angle valve job decking the heads and doing a mild bowl porting (and netting about 30 real horses) would be a better way to spend your money.

Well at least headers do make a measureable difference even though it is meager. Not like those dumb @$$ super coil guys whow spend 100's of dollars on improving the spark on thier engine. I have never seen a horsepower gain from adding a supercoil etc. I think the only way your would gain measureable horsepower would be if you were repalcing a broken or failing stock unit.

Ric

Synapsis

I could have gained a second off my headers, when I had stock manifolds on I had gutted cats. When I put the headers on, I replaced the cats with high flow units, and losing a little power in the process.

I'm saying that on a higher output engine, you'll see a bigger difference in headers than on a stock engine. IMHO, any engine could use a set of headers, because I see a 5 horsepower gain, or a 15 horsepower gain as a gain either way. If you're going to replace the manifolds, why not put headers on and get the extra gain while you're doing the procedure anyway? Sorry, I guess I see "performance manifolds" as just doing headers half-assedly. (Not trying to flame.)

Ratchet

Did you check out the link I posted.

I don't think there is anything half @$$ed about a 13.8 second camaro with all stock components Hydralic cam shaft no weight reductions single 4 barrel quadrajet and passes emissions tests.

I am thinking that these cast Iron exhaust manifolds must make as much horsepower as headers and are a onetime investment.

Exhaust manifolds last forever If you actually drive your car how many years can you get from a set of headers. 3 maybee 4 or tops.

Ric

Mark A Shields

Actually I'm pretty sure manifolds get hotter, due to the material they're made of.

Also, wire looms, and heat sleeving work wonders.
About burning hands, let them cool, simple as that.
Rust a problem, get them coated then.

I do agree about the leaks though. They're a pain and a bit embarassing, but the HP is worth the negatives.

brodyscamaro

i know magazines have had test were they gain 50 hp from headers on a built up engine

JPrevost

FYI, headers will cool down faster than exhaust manifolds. You'll gain more than just a few ponies. You will have to worry about fit and finish, still worth the extra power in my opinion. In my mind, if you're going to replace something, do it right the first time. Spend the money on exhaust manifolds but understand that the further you go from stock with a motor the powerloss is only going to increase exponetially.

Synapsis

My Iroc with SLP headers: daily driver, headers are Jet-Hot coated and my coolant temp sensor wire is within 1/4" of the header, not melting at all.

My VW that's had headers on it for 6 years: 5 1/2 years of daily driving, headers are still on, not rusting, not leaking (used studs), not even coated.

And as for a 13.8 second car with stock manifolds... it'd be a 13.2 second car with headers (most likely.)

But if you want to choke your engine with small manifolds.. more power to ya.

Ratchet

I am glad to see that this post has sparked so much interest.

I was just reading one of Smokey Unicks articles about small block chevys. He says that headers make 25 to 50 horsepower with open straight pipes going all the way to the back of the car. He also says that if you are running mufflers forget it!! Move on to page 36 where I will show you what you really need to do.

Later in the article he says that if you really have to have headers cause everyone says they are great and make tons of power then you should be using 4 count em 4 free flowing cadillac muflers two for each header. A minimum of 3" pipe and I am sure when he wrote the article they hadn't even started putting catalic converters on cars.

In short headers work but not without extremely free flowing exhaust.

Ric

Dan94GT

OK so you admit taht this was pre cat days. which means header/mufler technology has changed a lot in over 30 years.

Just seeing how people always claim.4-.6 et reduction and saw a before after dyno of somewhere around 36hp gain on stock 305s even says theyre worth it to me.

How can the spark plugs actually be harder to change? Unless the manifolds stock on your car are different than mine than this is The manifold runs above the ex ports and plugs, has all the lil tubes inthe way and the heat shields. Have to do most of em from underneath which is always a drawback getting under these low *** cars.

Synapsis

3" I pipe with cutout, got ya covered. I gain 2 tenths with it uncapped.

It was a hell of a lot easier to do plugs with my stock manifolds. I can't get to the #3 and #5 plugs with my SLP headers without working magic with a trimmed socket, some odd wrenches, etc...

Mark A Shields

Check this out, page 17 in Jegs. This is why I'm a Hooker man.
In fact, dyno tests with a 406 SBC have proven that the Aero Chamber helped produce 5 ft/lbs more torque than 2.5" open pipes.

Synapsis

Do you pay taxes?

Mark A Shields

funny. smartass.

HrdRockA4305

My floors don't get hot. Nothing has got burnt. Coated with VHT for $10... no rust. Spark plugs sucked to change anyway.

Picked up .6 and 5 MPH in the 1/4

I like headers. And I got the cheap ones. Everyone should have them as one of their very first mods IMO.

Camrs89

I can change all the plugs in my Camaro in 5 minutes!!! Helps to have a "gutted" engine bay.

five7kid

iTrader: (14)

Ratchet, you aren't all wet, but partially. Ceramic coating takes care of your main complaints about heat. If you could ask Smokey about your car specifically, he'd probably tell you to get headers.

But, this last Friday night I watched my bud run a 14.16 through his cast iron manifolds. He's done a bunch of stuff to that ZZ3 crate, and has 4.10 gears, but with factory dual cats and self-ported manifolds, that translates to a low-13 second sea level pass.

Oh, another racer runs his blown 383 '37 Chevy pickup with 3.70 gears and huge rear tires at 13.20's here (3700 pounds being pushed down the track). Through rams horn manifolds. He uses the truck to haul trash from his shop to the dump once or twice a week...

Ratchet

Just had to make a comment about the guys who see 36 hp gains when changing from cast Iron manifolds to Headers on a dyno run. The dyno has 4"diameter straight pipe after the headers off corse they make power.

Put a y pipe into a cat that goes into maybe 2.5 in pipe that goes into a single muffler tucked up sidways under the rearend and then split it back up into two tailpipes and you have added a ton of restriction maybee the 36 hp on the dyno will net you 5 or ten on the car where it counts.

making horsepower is all about pumping air through the engine so remove the restrictions and you should make more horespower.

I believe that comparable gains can be had by installing the ho manifolds on a STREET/STRIP emission legal f body as can be had by installing headers. Once the Ho manifolds are on they are no longer the restriction the new restriction is the 16 or so feet of 2.5 diameter pipe, the catalytic converter(s), and the muffler that is behind them.

IMHO
Ric

five7kid

iTrader: (14)

No offense, but what one believes doesn't change reality. The intent of headers is two-fold: 1) to reduce restriction at the port exit; and 2) to tune the exhaust pulse so that the reflected shock wave is moving back away from the exhaust valve as the valve begins to open again - this produces the famous "scavaging" effect, which "pulls" the exhaust out of the cylinder to aid the piston in its act of pushing the spent gases.

Long tubes work best at #2. But, the restriction encountered at the exhaust port exit is the most critical of the restrictions that exist in the exhaust system, and shorties are less restrictive than the typical cast iron exhaust manifold (which are only designed to route the gases away from the engine and last for a long time, not optimized for power).

FWIW, when I received my Hooker 2055's, I noticed that the collector ball flange had a measly 1.9" diameter opening where it connects to the y-pipe. I emailed the Hooker tech department, and their response went something like this: "It is that small to ensure a good seal. By the time the exhaust gases get there, they've slowed down significantly, so it doesn't cause a restriction." Now, I'm sure they know more about performance exhaust than I do, but that answer didn't keep me from opening that up to 2.25" after I knew where the y-pipe was going to contact it. However, a bunch of guys here have used those headers without that mod, with no complaints about performance. And, contrary to my examples above, there are only a handful making a butt-load of power with cast iron manifolds.

five7kid

iTrader: (14)

Another thing, who said 2.5" pipe after the two sides come together is a good idea? The almost universal consent is that 3" is minimum for a performance engine.

formul8!!

The E/T and Dyno #'s below are on the stock 350 manifolds.

Momar

Correct me if I am wrong, but I thought I had read that those manifolds were just the stock 350 tpi manifolds which are the best thirdgen manifolds but still no where near what headers are.

Ben

TBI305Camaro

Manifolds rust
Manifold can burn wires
Headers do not make it hot inside the car
plugs easier to change...just need a socket and a wrench
with good bolts and gaskets dont leak...

Just get headers...cheaper and better.

Acceld Z

I ran a 13.5@106 through my stock exhaust manifolds. I now have double coated headers and you can touch them 5 minutes after the car has been shut down.

TBI305Camaro

He said they burn your arm...touch an exhaust manifold...gonna do the same thing.

Acceld Z

No ****, what's your point?

deadbird

So do manifolds, the only difference is manifolds take longer to heat up due to the metal thichkness and cool off slower for the same reason.

They make gloves if you're that impatient to wait for the engine/exhaust to cool.

They make sleeves for the same purpose.

Buy a correct set of plug wires and retainers and you'll have no worries.

Tighten them down properly or use locking bolts (the factory manifolds use bolt retainers as well..).

Use a light coat of Ultra Copper RTV on the (paper) gaskets or buy dead soft (aluminium or copper) gaskets and that worry is gone.

If your exhaust is getting hot enough to burn peoples feet thru the carpet, you've got serious problems..

Buy a $5 heat shield.

And changing plugs with the stock manifolds on an F-body is a simple task ??

What on the sides of the motor can't you get to, the starter and the oil filter ? There isn't much to get to from the topside below the heads.

Sleeves.

Not trying to be an **** mind you but, your arguement against headers doesn't hold much water. There are only gains to be made, maybe not nosebleed HP gains but, subtle and, when added as part of an overall system to the motor, only compliment and aid other mods done.

89IRO

Well it seems to be that I am the only person here that agrees with Ratchet. I'm getting my exhaust done on my IROC-Z (high-flow cat., Spintech muffler) tomorrow. I in no way want headers on my car. Good ol trusty manifolds for me- headers- expensive, expensive to install- 5 h.p. gain (not worth it to me)- look really ****ty unless you spend a fortune for jet-hot- rust (unless jet-hot)- and it seems to me that our cars didn't have much room in the engine compartment to begin with. Sure, if I had a race car or if I were pushing 400 h.p. I would probably run them- not for my 250 hp camaro. So there you go Ratchet- you have a supporter. -89IRO

Wootah

When im done with my stero system, im going to dyno my car and buy hooker super comp headers, and super comp cat-back with the aero chamber 2.5 in 3 out, and taking off my cats, and dyno it after im hoping to gain 50hp+... maybe im dreaming tho.. what should i expact?

fast86z28

yea just dont put lg4 manifolds on a 350, thats what i got including the rest of the lg4 exhaust and yea its kinda KILLING me...im trying to break 14s be4 buying headers and exhaust just to see if i can do it w/o spending lots of money...right now im at 15.3 so im thinkin with headers and 3" exhaust i should be around 14.6-7

TRAXION

... stupidity at work. If newbies are reading this then don't believe what he just said. He's talking out his anus.

The HO Manifolds aren't really 'high output'. They are just labeled that way because the collector portion of the manifold is a little bigger. But - they're still tiny. I've personally compared these manifolds against SLP headers. Any 350+ ci engine will benefit from headers. They might only show a 15hp gain on a stock motor but they will show A LOT more on a modified motor. When you buy headers you want to buy ones that come with a Y-Pipe so that the system is matched. SLP headers with the 2-1/4" y-pipe into a 3" catback flows a lot more exhaust air than the "HO" manifolds and stock y-pipe. Period.

Tim

Mark A Shields

Very well put. The more ponies you're making with stock manifolds, that means just the more you'll be making with headers.

Sure on a stock 350, you might see a 15hp gain,
but build that 350 to make 350hp on manifolds, and add headers and you'll get a 30hp gain, as an example.

Momar

LOL, well put. Even a cheap set of headers is much better than manifolds.

Ben

formul8!!

The worst set of headers is better than the best manifold.

Ask anyone who has installed them over stock manifolds and about 95% will say headers give you a solid noticeable gain.

Sure, headers are not cheap. Welcome to the hobby.

Momar

Heck, those manifolds he is looking at are 90 a piece US. If he needs a y pipe then that will end up costing as much or more than headmans with the y pipe. Heck 90 a piece compared to like 109 for the headman headers by themselves if you had to have a y pipe made for both you just saved like 70 dollars.

Ben

CamaroDriver

You can port stock exhaust manifolds. David Vizard has stated in many of the books I've read by him that just basic porting in the exhaust manifolds (similar to pocket porting heads) works suprisingly well.

The book I have in front of me now, which was written by him, says that he tested MANY different exhaust manifolds this way on engines in the 280-350 HP range and picked up AT LEAST 10HP, 15 being the NORM, and has seen as much as 22HP!!!!!

That's by simply gasket matching the manifolds, increasing the inlet size on the bottom of the manifold to create a lip below the exhaust port on the head.
IMO, the only problem would really be after the manifold into the y-pipe. SLP as well as Random Technology make y-pipes to fit the TPI manifolds (BTW, are the largest/least restrictive) for ~$200. I would definetly recommend that if you're going with the stock manifolds.

Headers ARE NOT the only way to make a good exhaust system.

formul8!!

Stock manifolds have one serious flaw- exhaust scavenging.

At higher RPMs, the scavenging actually pulls exhaust out of cylinder and intake air into the cylinder. Manifolds are extremely poor at doing this, no matter what you do to them.

There isn't enough separation between the exhaust openings and can actually pull exhaust from cylinder into another cylinder.

I will stand by manifolds being extremely poor compared to a header.

Momar

I have read part of his book on budget small block chevy's(including the exhaust section) and he was also using better manifolds than we start out with for the most part like the ramhorns and such. He also talked about someone who welded dividers between the cylinders to help keep the exhaust seperate for scavenging like headers do. The think is though is with the ram horn manifolds it keeps the cylinders seperated into 2 pairs of 2 on each manifold to start with until the collector so you dont have all 4 coming out into the same area at once. Also they appear to be more contoured. Another thing he said was that lowering the bottom of the port on the manifold helps because if there is a low velocity area at the botom of the port and the drop off coming out of the head to the manifold can help keep velocities up.

All this said I would not spend the time/money on the manifolds because there are some pretty cheap headers out there.

Ben

formul8!!

Exactly. For what it's worth in time and labor, you will be almost to the cost of headers and will still come out ahead in power gains.

breathment

HMMM i don't know about u guys with headers. but its a HE!! of alot easier to change plugs with headers then it is without. i mean now i can actualy see all my plugs, and i can get to all of them from above the car... with manifolds it took me close to 2 hours.. maybe 20 min with headers.. while we are talking about useless reasons to not like headers. here is a useless reason TO like headers... they look cool..

Momar

yes they do

Momar

another

CamaroDriver

Well you need to read it again. As I said earlier...... I have the book here right in front of me. He says "....I made a point of doing basic porting on several sets of iron manifolds of differing configurations to see what they'd typically do. I was surprised at the results." Then he continues with what I've already quoted him on. I guess I should have quoted ALL of what he wrote so nobody would make any assumptions (which seems to be quite often here. )

That's all find and dandy IF he was actually talking about the ram horns. Thanks for the info though.

[quote] Another thing he said was that lowering the bottom of the port on the manifold helps because if there is a low velocity area at the botom of the port and the drop off coming out of the head to the manifold can help keep velocities up.[quote] That's correct, but that is what causes that unwanted inversion. The low velocity area can easily be drawn back into the ehxaust port which is what that step, that's created, impedes.

Well..... that's your opinion, and everyone's entitled to that. I'm just trying to show that