Do crossover pipes (h,or X)make a difference on our sixes??? I have to put new exhaust on the 62. I've got Stovebolt headers (along with offy intake and 390 Holley) and plan on running 2" maybe 2.25" (if it will fit around the z Bar) and 18" glasspacks, would a crossover help?

It will help your sound if nothing else. It'll balance out the 'rapping' and make it sound more like a V8. I wanted an X, but an H fit better. I LOVE how it sounds and how it was done, along with the price!

The place that did mine is over on 122nd, near Airport Way. The guy is kinda cocky, but did a reeeeeally good job and I'll never recommend anyone else! Turns out he also builds custom headers. I think I wrote about him back in January if you do a search.

NONE!!

On an inline 6 engine; installing headers separates the exhaust to aid in "exhaust relief".

If you combine it, with a cross-over you defeat the whole purpose of adding them.

This has been debated at great lenght here. Please check past posts, for more detailed information.

Good luck.

Well, I wouldn't be so sure about that. Don't know about our sixes becouse never done an experience regarding this before, but there are some people working on V8s to take all its juice using stock parts mostly and they believe the pipes do some difference.
Here is the link:
http://www.castheads.com/2into1_systems.php

The only problem is fit them inside the car. Hehehe

When I instaled the H pipes in my car it ran so better that I had to change the jets in my carb.
Now the car runs better, sounds like more uniform. I noticed a little better fuel milleage, and better performance also. It runs smoother and faster - you can feel it. In the other hand it sounds quieter. But know I can desacelerate the engine without hearing that kinda shot noises.
I'm talking about a street car that revs 5500 not a full racing one, so I'm not sure about it's performance in very high rev engines...

There were some 'dyno tests' done on 400+/- (CID) V-8 engines using the "H/X pipe" in the mid 70s and these indicated some (very small) increases @ high RPM.

However; NONE of this data is relevant to the inline six today, operating on the street.

This engine fires front-back in the header system and different than ANY V-type engine.

This bogus "crossover/ballance tube" was/is used by Muffler Shops to reduce noise W/O changing the mufflers.

Headers WILL make noise; so you must use the proper mufflers and operate it accordingly.

Don't 'fall for' the "crossover scam"!!

Happy trails.

PS: You'll need ones longer than 18".

I dont know if I would necessarily call it a scam when it comes from the mouths of fellow inliners, mr c dan delux here at inliners did a dyno on his 261 with x pipe and without, he got 8% more hp/torque under 3500rpm!! and thats DYNO PROVEN ON A STRAIGHT 6. I have a x pipe on my 235 and flowmasters in my truck and love it, sounds great, deep and crisp, but on the flip side I'm not trying to shatter windows with a 300 decibel fart explosion sound either, try it with and without, its only 60 bucks!

It's a "scam" because it takes money from the customer for something that's unecessary or bogus. It's just that simple.

Sound is NOT the issue. One can make their vehicle sound ANY way they wish.

Headers separate the exhaust flow, so it can move out faster and that's why people buy/install them.

These bogus pipes combine it again, slowing it back down, defeating the basic purpose and that's stupid. Plus; a waste of time, money and effort.

It started in the 50s because, it was a quick fix for "noise" tickets. :rolleyes:

One attractive "dyno result" changes nothing.

You must build your system (proper mufflers) to comply with noise regulations & 'common sense' operations with each side separate. To do it otherwise is simply misguided. Plan your system and just have the Muffler Shop bend the pipes to fit your vehicle.

Happy trails to all.

A H pipe does not slow the exhaust down in any way. A X pipe may??????? to a small amount. But Depending On where it is installed on how it may effect the over all sound Or performance.
Just Like Headers If the Mufflers are placed to close to the Collector The Exhaust will be Louder
No matter what the muffler is. The further back the muffler is from the collector the Quiter the exhaust will sound,And you will not have a rappy sounding exhaust.

Headers allow the exhaust to flow more freely
full lenght Or shorties. Because it moves the collection point further away from the ports/
Or another way to look at it is, That IT's not bunching it all into One chamber. Even Tom Langdons duals Improve over all performance.Main reason is, it is seperating the exhaust into 3s and Not all into one small chamber/Manifold which in turn lets exhaust flow more freely.
Even some Headers were built as 12 into 1 Still improving the flow over a stock Resticting exhaust manifold. Bottom line here is Move The collection point further down away from the Ports
Or split The amount into two For a less resticting exhaust.

maybe to long winded here But Thats my 2cent imput in this matter.

I don’t know about how they work in a street application, but on our race engine we found that with the “X” pipe we had a gain in torque and HP. But after over 50 dyno pulls with our mule engine and countless header designs, the best scenario we found was a three into one system with a “Y” pipe and properly designed anti-reversion cone for our engine.

If you look at the effects of wave travel in an exhaust system, pressure waves, both positive and negative, are traveling up and down the pipe, and depending on the type of wave and when it hits the engine, it can help you or hurt you. A negative wave hitting the chamber during overlap is a good thing, it helps the next intake charge and results in more cylinder fill. A positive wave does the opposite and can cause poor fill, excessive heat, and even detonation. The idea of the anti-reversion cone is to let the negative waves pull exhaust out of the engine more easily than the positive waves push exhaust back into the engine.

Also we played around with the length of the collector till we found the optimal length, which had a lot to do with the HP and torque gains. We did all our design and testing with one of the best NASCAR exhaust guys in the country Boyd Butler.

Gentlemen;

Mr. Butler is NOT running an inline six in his NASCAR vehicle and we all wish him good luck at the races.

When "hopping up" one of these low horsepower engines, everything MUST work in unison.

These bogus pipes (alone or together) prevent that because; they re-direct the exhast flow from what the headers were designed for.

Muffler Shops sell them to CYA misleading the customer, so they won't have to do a job over (FREE) should the customer get a "noise ticket".

You can't confuse what some do on the race track with what we do here, It's a different world.

Happy trails.

From what I understand (I'm usually a v8 guy) the pulses should have no barring on weather they fire front to back or side to side, top to bottom, it is the different cylinders firing in the different header pipes to help with the scavenging effect, not just to reduce noise. I hold little vitality to any test done in the 70's or earlier, so much has changes that these old rules do not apply any more, remember the old 30/30 cams?? Lots of duration little lift, because of poor flowing heads, cams and heads have come soooooo far that you cannot compare them anymore. What is faster a 2006 Z06or a 70 LS-6??? Both have about 450HP. Now back to the six surely a crossover would not defeat the purpose of adding the header, after all you have SO much added surface area of pipe, increased flow, so with adding flow of more surface area adding a crossover is not going to defeat it and bring you back to "stock" performance, just can't happen so that throws you theory about defeating the purpose of installing headers.
Do disrespect in my post is intended, if I offend I apologise.
Jon

Dear Jon;

None taken.

I'm not familar the (450 Hp) engines you mentioned. Were talking of a 60s 150Hp engine and trying to add as much as possible, on a low budget.

My point is simply that ANY "re-combination" of the exhaust gases (flow) defeats the goal of what your trying to acheive with headers.

Perhaps; not in total like you say, but even "in part" is a waste/misdirection. The pipes need to be separate for best results.

Happy trails.

I just think its funny that when dyno data is present for v8's-its irrelevent, and I'll concede they are slightly dissimilar but dyno data from a 261 on the same day only thing that changed was an no x pipe/glasspacks vs x pipe/flowmasters and for some reason it is arbitrarely disregarded by you john, how much more relevent can it get? I am probably the most skeptical person alive, but the numbers speak for themselves with x pipe coming out on top!

He is a little more for everyone to think about/ bite on.And I don't remember where i read it.

But If you down size the pipes as it nears the back of the car,This helps keep the exhaust temps up. Inturn It flows better???? Rather then keeping lets say a 2 1/2 exhuast all the way to the rear.As teh exhaust Cools The flow slows down.
This is what was claimed to be.I never personaly tried it So I honestly have no clue as to how true this can be.

Larry, I thought it was the other way around....with the pipes gradually getting bigger at the tail end???

I remember seeing someone's website where they built their own headders and necked them up, as they got farther out....

I'e seen this before (at least heders) Hedman has thier "torque step" headers, 1 1/2-1 5/8, but also I have heard what larry was saying too about smaller pipe after the muffler. on a stock 230 will any of this make a difference, that is my question.

D-261;

One test, by one person; is NOT proof of anything, only an indicator. To validate this thesis would require several tests by different people, obtaining similar results, over time.

I've seen (over 40 years) all the reasons why they do NOT, for the reasons mentioned here and on previous post on the subject.

It's ALL theory and suposition with no proof.

The NASCAR vehicle runs a precision high performance V-8, that probably turns 4-6,000+ RPM for hours at a time. In "that world", they work as Mr. Butler points out.

Big difference.

I agree, you will see more gains in a High perf engine combo,,,but as also stated earlier, it will quite it down.

MBHD

I have built my own headers. And did research in this matter some time ago. In reguards to equal lenght and tube sizeing,HP,torque.And collector size and lenght.

My headers are stepped up from a 1 5/8 to 1 3/4
the last 10-12 inch is 1 3/4 But also my header tubes are with in less then 1 inch of each other.
anything with in one inch ( give or take) of each other is considered to be a equal length header.
If the header /exhaust is to Big you lose back pressure Which in turn hurts over all performance.

As exhaust cools down it also slows down. So the Idea was to down size the Pipes as they got further away from the mufflers to help keep heat in the exhaust & to keep it flowing.
but like i said before I never tested this so I honestly have no clue as to it's effects exhaust flow.
Seeing that I do not run a full lenght exhaust.And
Not offen do i have mufflers on the car.

On a stock/Motor about the only thing that will make any difference is doing away with the stock exhaust manifold. If you build your own headers
No tube bigger the 1 5/8 For the hp that a stock motor has a 1 1/2 is fine The collector 2 1/4 The main exhaust doesn't need to be any bigger then 2 1/2. (2 1/4 is Fine)

Even for a healthy built 6 ( 200-300hp) the 1 5/8 header tubes and a 2 1/4 collector is all It needs
especialy if nothing has been done to the head to help it's performance.(breathing ability).

I have one year of daily driver experience using an X pipe on a '56 235 with Fentons and two 24" cherry bombs. It has quieted the exhaust noise (deeper tone, minimal rap) and I can decelerate w/o having to worry about noise bothering my neighbors.

I live in the piedmont (foothill) region of central Virginia and am consistantly challenged with hills and occasionally a mountain pass @~2500 ft. From the onset the X was installed I perceived better pull up hills and the mountain pass.

Would I do it again? Yes. Do I think it has better value than washing the truck or rolling up the windows to decrease drag? Yes. Do I have dynometer testing to validate my findings? No.

Larry, you right about the tail pipes and exhaust gas temperatures. Once the gas has hit the muffler, everything from there is out doesn't matter much. Our race cars never seen the any difference from 2 1/4 to 3 inch pipe. The bigger the engine of course, the bigger the pipe needs to be, but I am talking 455 plus cubic inches.
As you and some of the other true racers have seen, a stock 230 or 250 will not see any difference no matter what pipe you put behind it. Headers need to be true headers, equal length and sized for the rpm range of the engine. Oversized tube size can kill a engines power curve just as fast as a undersized or stock manifold. With out a intake, cam, carb, and ignition change, it just won't matter!

As for H or X pipes, we have seen first hand how well they work, they are quieter, and make more power over a separated exhaust system, Period! As for redirecting the exhaust back to single pipe restrictions levels, thats crap, both types of cross over allow the gas to exit out the pipe with the least resistance at any givin time. In reallity, you are giving both sides extra pipe so its like four tail pipes instead of two. They work just as well on low rpm torque engines as well as big rpm race engines.

Six cylinder engine may not ever see the gains a V8 does due to the odd firing order and number of cylinders, but it sure can't hurt. Its been proven on the dynos and at the track.

Straight Axle 63 hit right on the head, if you are comparing 40 year old test or even 5 year old data, you are behind times. Just look at what has happened to oils in the last couple of years. How many 9 second street cars were around in the 70's? How about 12 second diesel pickups? All I am saying is, times have changed and so has a lot of thinking..... go to the track and test it your self.

Joe

Dear Joe;

What racers prove on the track with high power/displacement V engines, running constant high speeds, isn't relevant to a 60s 150Hp inline engine, on the street.

I only quoted the 70s data as; that is what many use to justify this thesis. It's not relevant either.

A dual exhaust system for the "street" is a different situation. This engine will NEVER see the speeds "race engines" do and will gain nothing from a bunch of senseless plumbing, under the vehicle. :rolleyes:

As a matter of fact; when Muffler Shops put this garbage on, It's welded permently in place, right in the way of everything, as opposed to the separate system, which is NOT in the way of anything.

We may disagree with the theory & that's okay. But this guy will have nothing but bad luck "down the road" if that crap is on there, instead of installing the proper size mufflers to start with.

That's the way it is, in the 'real world' and has been since "duals" first began in the 40s.

If these devices work (for you) on the track, than 'by all means' use them and we ALL wish you many safe finishes and your share of wins too.

Well, after all that, i'm still thinking its better to use H/X pipes, as they proved work, on track or going up the hills, and its not that expensive to hurt the pocket.
What I just saw here was someone who starts defending an idea and had no longer valid arguments to support it.
Anyway, even with small, almost insignificant, gains. A gain is a gain, right?

it proves nothing...please! John I have nothing but the upmost respect for you. But to to say it proves nothing? What has transpired here with a dyno result is the antithesis of that, it proves it works with a relevent powerplant, the more you test it on a dyno the more reliable it becomes statistically speaking, but that argument cant be used as a tool to ignore documented data

and my research shows me that a staight pipe system (headders and straight muffler like a glasspack) is best for high rpm hp in the 5000 plus rpm range, but poor for power under 4000rpm because we have no back preasure on exhaust. but x pipe gives a little backpreasure at lower rpm like 3000rpm and less, but our 6's arent going to see 5000rpm often, which is why x pipes are great for our low rpm/non race motors

A couple of you have stated that that backpressure helps low end performance; this is not true. It is the increased velocity of the exhaust gasses with reduced diameter pipes that causes the improvement, not backpressure. An X crossover should actually decrease backpressure on tuned length headers on an inline six, as the exhaust pulses will be interleaved and flow through two pipes rather than one, as Joe pointed out earlier. If backpressure helpd anything, you could put a restriction anywhere on the exhaust system, including at the end of the tailpipe, to acomplish that goal; we all know that sticking a potato up your exhaust pipe will not improve performance, but it certainly adds backpressure.

Gentlemen;

The question (orginal topic) was NOT about what works on the Race Track; with High powered-high performance precision V-8 engines.

These folks (NASCAR) believe in them because they function in that arena. On the race track, engine running @ maximum with the exhaust @ at a very high volume/different frequency.

A used-low horsepower (1962 design) inline engine, generally operating well below maximun in It's power curve, is NOT the same thing at all. Not even close. :rolleyes:

My responses here are based on what happens on the street, with slightly modified passenger cars & light trucks, not 'race cars'. They operate ONLY on the track.

Other than changing the tone/noise level, all of this bogus plumbing is worthless and creates more problems than it could ever solve, if it worked, as suggested.

This is all based on 40+ years of watching it happen to others that "fell for" the Muffler Shop BS.

Mr. Straight straight axle 63;

Don't you "fall for it"!! Build your system with (straight through) mufflers so the noise is "within reason" W/O any of this 'monkey-motion' or 'pretzel pipes' on your car.

Happy trails to all.

An "H" pipe - or even better - an "X" pipe will add about 5 HP to your combination if you rev it to about 4000 RPM. Less at lower speeds. It is up to you to determine if the expense is worth this kind of gain.

To me it is, assuming it is neatly packageable.

My opinion is based on thirty-some years of engine dynamometer testing observations in the Engine Performance Development Group at Ford Motor Company Research and Development Center, Dearborn, Michigan.

Your results may vary.
But I wouldn't bet that way.

TFF,

Was the any of the dyno data at FOMOCO obtained on inline six engines. The reason I ask is that V8 data would be suspect when applied to an inline six. If it was on an inline six, how did the addition of a crossover pipe affect the torque curve? Did the torque peak occur at a higher RPM? Did the torque curve flatten, with all points higher than the non-crossover system? These would be relevant questions.

I read recently that having even exhaust pulses on a V8 actually decreased the horsepower and made the torque curve peakier; this was on a 180 degree crank. It could be argued that the problem was in having a 180 degree crank, but the concensus was that having equal lengnth primaries degraded the torque curve. I have no axe to grind on this matter, I just question everything. Cynic?

I stand corrected on the x pipe creating backpreasure, makes sense because an x pipe cant increase the scavenging effect if it created backpreasure in any way

Neither the H or X pipe increase back pressure.IT is just there to balance the exhaust pulse.

Dear Frenchtown;

These are the 'dyno tests' I refered to at the onset here.

As I recall; they were done on the Ford 351-C (big blck) engine which was used a lot in their 1/2 & 3/4 trucks and Station Wagons. This engine had the valve timing retarded too (for SMOG) around that time and this is one of the reasons for the testing.

Motor homes using it had to change the chain/gears to pull any hill.

My 1972 wagon had one with dual exhaust (separate) from the factory too. I got it from a "fleet manager" who had changed the chain/gears and drove it to/from Las Vegas at the time. By 1983 it had over a hundred thousand and was still running great.

No "H or X" pipes on wagons or motor homes (where needed/if worked) but some did appear on the Ranger trucks around 74. These also had dual cats as well.

This truly was a sight to see; A 2" pipe out of each header into a crossover-X pipe-crossover-cat on each pipe-then a muffler on each pipe-to tailpipe**.

I guess they (Ford) were trying to offset the horspower lost from the EPA garbage, forced upon them. There were "test results" published to save the muffler aftermarket then too.

Either way; none of this testing was done on the inline 6 in that era, or applies today for one on the streets.

Also; dual exhaust systems don't add horsepower, they just replace what the single system took away.

Happy trails.

** A friend cut his off (whole system) and hung it on the back fence for all to see. His truck (brand new) would barely run across an intersection if you 'flored' it from a dead stop.

Gentleman,
I agree with John that if you are running a totally stock 216 or 235 an H or X pipe probably won't make a difference. On the other hand if you are driving a Six with higher compression, a modern cam, high voltage ignition, ect. you are in a different ball game. When I drop the hammer next to a 350 chevy I want every bit of HP I can get and even 4 or 5 hp makes a difference. You have to realize that John likes to keep things basicly stock, he always states that a vehicle is worth more stock than modified. Although I would have to debate that.
We are looking at this from two different places: Are we running a 300 horse six or a stocker. I use my sedan for touring and going to national shows. I sometimes pull a car trailer with my wife roadster on it so I have built my six to delvelope the horses required. I also run 4 wheel disk and radial tires which some people don't believe in.
In closing build your car to suit yourself as you have to put up with the end result.

When I first mounted headers on my daily 235, mostly V8 race experts said it would make no difference for a stock straight 6.
It did for me, which is what matters after all.
These engines talk in such clear and easy to understand language, no dynos or experts can tell you more than you can figure out by yourself with safe experimentation.
A lot more fun and exciting anyway.

Straight 6 likes straight short pipes.
The easier the engine can breath with less restriction, the better the performance at higher rpm.
For hauling loads with trucks, keep the original simple intake/exhaust for better bottom end torque.

Mufflers and crossovers on a street straight 6 help tuning your exhaust sound for the most part.
Just go with what sounds and feels best to YOU.
Gains and losses in power are too insignificant to worry about in the mid rpm range.

This guy really likes his (X)pipes.

Not a inline but, shows what a good exhaust can do!
http://www.yenko.net/ubbthreads/showflat.php/Cat/0/Number/281982/an/0/page/0#281982

OK I will weigh in too..Bill & Runner have my vote. I love these posts cause they get the blood boiling and that is a healthy thing. To each his own..but I have gotten great insight, advice, no way I would do that, and a multitude of other opinions from this group. Keep 'em coming.
Duce

Bald Eagle,
You are right to question everything you read on the internet. Since I personally worked on dyno testing V8s that is where my first hand information lies. Since I have raced and rodded sixes for three decades and have studied others results with those engines my knowledge of their results is admitedly second hand, but well founded in fact.
Reducing the peak pressure spikes with the addition of an x pipe will slightly reduce the effective backpressure and,as such, will only slightly shift the torque and horsepower peaks to a higher speed.
A 180 crank in a V8 is akin to making a four cylinder engine out of it since two cylinders now fire at the same time. What do you think would have a greater effect on torque - turning a V8 into a huge four cylinder engine or evenly spaced exhaust pulses?
Keep asking good questions, and take all the opinions with a grain of salt.

TFF,

Actually, a 180 degree crank makes two four cylinder engines with even firing pulses on each bank on a V8 rather than the uneven pulses which you get with a typical 90 degree throw crank. The 90 degree placement of the banks means that the cylinder opposite on the same throw will fire 270 crank degrees after that cylinder. A 180 crank would only make an I8 into two four cylinder engines with one cylinder of each firing at the same time.

But my real point was that even firing pulses actually degrades the performance of V8s for some reason. On a V8, you could build a header that would give even firing pulses on a 90 degree crank by having the primaries of the end cylinders of one bank tied to the inner cylinders of the opposite bank. This has been done, but the results were dissapointing, from what I have read.

Pure purpose built racing V8 engines tend to use the flat 180 degree crankshaft for lower rotating mass and even exhaust tuning on each bank of cylinders for greater power and engine acceleration. This includes Forumula 1 and later Indy V8 engines, unless rules mandated the 90 degree "stock style" crankshaft configuration. The detrimental effect is engine vibration. Back in the sixties, V8 engines racing engines with 90 degree crankshafts use in mid-engine cars, such as the Ford GT40 and Indy cars, had the elaborate exhaust systems on the rear of the engine with 2 headers from each bank of cylinders to each collector. To my knowledge the results of even exhaust pulses is still advantageous. Exhaust tuning is fairly complicated, so individual results must be viewed with scrutiny.

http://www.e31.net/engines_e.html
http://en.wikipedia.org/wiki/V8

On the first website, the information stating that all boxer engines can be perfectly balanced (without balance shafts) is incorrect. A flat four cylinder engine cannot be balanced completely.

We used to have a small block Ford racing around here ( drag race only ) that had 180 degree headers. The sound it would make was just like a high reving 6 cylinder. It was a mess of tubes running every which way under the car. It sure ran good though! Joe

I think it´s time for me to chime in.

"chime"

Got the mentioned 261 with the x-pipe and the dyno proofn 8%.

Jim is right whe he says that on a stock 6 there will be no big differenc.

My 261 is pretty warmed up and it made a difference. Period.

My exhaust guy (an 70 year old hand with log time racing experiance) did a normal split setup first.

Than he sprayed the tubes from the headers to the mufflers with a can and drove the car real hard.

He inserts the x at the first location where the paint was not burned off from exhaust heat.

He told me, that he got that trick from his teacher, who was involved building the famous german Autounion racing cars before WWII.

What can I say? It works for me.

Frank

Frank, That's an interesting practice. It's an idea we can try in the future. Also, looking forward to this years Headbanging pics.

Dear Frank;

Could you send some photos/data sheets of how you performed these tests??

Myself; as well as many others, would like to see how this experiment was done.

You (to my knowledge) are the only ones to have done these tests, on a inline six engine with duals.

Thanks.

The 41 get´s a new spray over in the moment.
When I got it back I do some pics of the setup.



Meanwhile I try to find the Dyno test sheets and scan them in.

I don´t have photos from the process of building the exhaust or the dyno test.

Frank

Another good idea based on Drew's one - I liked a lot - is to paint the pipes and where it starts to not burn the pain is a good location for installing the oxygen sensor for the air/fuel ratio meter.
I'm satisfied with my H pipes and don't think they cause a flow loss.