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Mordor67
Tribal Scout

22 Posts

Posted - 03 May 2016 :  5:04:13 PM  Show Profile  Reply with Quote
Picked up a running 400 off of CL.70 YD code with #16 heads. Pulled this thing apart and was astounded how good it looked. Looks like the bottom end has never been apart as the rods weren?t marked. Perfect crank, cyl walls, even the bearings showed very normal looking wear. Tempted to just freshen it up and reuse everything including the pistons. What kind of RPM will I be limited to w/ stock rods/pistons and are those heads any good(small valve)? Not looking to go racing just strong motor with what I got

tjs44
Cochise

USA
412 Posts

Posted - 03 May 2016 :  7:30:59 PM  Show Profile  Reply with Quote
16 D port heads I believe were big valve 68 heads around 72 CCs?
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Tub
Sitting Bull

172 Posts

Posted - 03 May 2016 :  10:28:53 PM  Show Profile  Reply with Quote
In 1970, the #16 heads were small valve/press-in stud, listed at 78cc on some sites--Different from the '68 #16 big valve heads. The '70 YD code is listed as a 290hp 2 barrel engine.

http://www.wallaceracing.com/enginesearch4.htm

http://www.antiquecarparts.net/tech04.htm

http://ronspontiacpage.com/reference-pages/stockheadspecs.htm

http://www.classicpontiac.org/FAQ.asp?myPage=V8HeadInfo

http://www.bassettracing.cz28.com/custom3.html


"...What kind of RPM will I be limited to w/ stock rods/pistons..."

We crossed the line at 6000rpm with stock rods and Pontiac replacement cast pistons, with a '68 Firebird Stocker. BUT, the pistons were new, and the rods were only 7 years old. If your rods and pistons are original, they are what--46 years old ? There are some of these old engines still running. How lucky are you ?

The '70 block is a good one. It would make a good foundation for either a good forged rod, forged piston 400, or a stroker. I'd go with 6x-4 heads for a pump gas 400 and 6x-8 heads for a 4.21 or 4.25 inch pump gas stroker. You could use the small valve 16's. But most would want to upgrade with bigger valves, screw-in studs, & new valve seats. Then, you still have around 10:1 compression, on a 400, unless you run dish pistons. I'd spend those extra dollars on some 6x heads, which have 2.11 intake valves, screw-in studs, and hardened valve seats. Add some one-piece stainless valves, and a good complete valve job,and you'll have a good set of pump gas friendly heads.IMO

Lots of guys still run rebuilt stock rods, with ARP bolts. But these usually cost around $200 or more. So, most usually go with at least the RPM 5140 forged rods. And the SP L2262F forged flat top pistons are the most common used in 400 rebuilds.

http://www.racingpartsmaximum.com/sae5140stockrod-2.html

http://www.ebay.com/itm/Speed-Pro-TRW-Pontiac-400-Forged-Coated-Skirt-Flat-Top-Pistons-MOLY-Rings-30-/190855081106?hash=item2c6fd96c92:g:6B0AAOSwzgRWvhp2&vxp=mtr

Here's a cast rod 400, with 6x heads and forged pistons.

http://lenwilliamsautomachine.com/400_Long_Block.html

Edited by - Tub on 03 May 2016 11:20:11 PM
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Mordor67
Tribal Scout

22 Posts

Posted - 04 May 2016 :  06:09:10 AM  Show Profile  Reply with Quote
Thanks so much for the replies. I will start looking for some 6X heads. Good info and what I expected to hear. Got some reading to do. Also, I want to run zero deck height. I checked the stock pistons before I pulled them and they were about .020 down.If I get new pistons and rods, would I have to assemble everything to check this? and then back to machine shop?
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Tub
Sitting Bull

172 Posts

Posted - 04 May 2016 :  11:05:12 AM  Show Profile  Reply with Quote
"...I want to run zero deck height. I checked the stock pistons before I pulled them and they were about .020 down.If I get new pistons and rods, would I have to assemble everything to check this? and then back to machine shop?"

Yes. To get EXACTLY zero deck height, I don't see any other way to do it. However, the SP L2262F forged pistons have a pin height(compression distance) which is .014 more than the factory 400 pistons--1.714-1.700 = .014. They come in std, .020, .030, .040, & ,060 oversize.

http://www.ebay.com/itm/Speed-Pro-TRW-Pontiac-400-Forged-Coated-Skirt-Flat-Top-4VR-Pistons-Set-8-030-/190855076806?fits=Make%3APontiac%7CSubmodel%3A400&hash=item2c6fd95bc6:g:ZnwAAOSwDuJWvhoN&vxp=mtr

So, new 6.625 rods with the SP pistons should raise the piston tops by .014. So, IF your .020 number is accurate, that should give you a .006 deck height. But, the only way to know FOR SURE, is to assemble and measure. If your deck height is more than .006, instead of having the block deck machined, you could buy Cometic .027 x 4.160 head gaskets.

http://www.jegs.com/i/Cometic-Gaskets/245/C5711-027/10002/-1?parentProductId=1288713

If you have the big end of your stock rods resized, that will shorten them slightly. This will increase your deck height slightly.

Another way to adjust your deck height is to order Auto-Tec pistons. They will move the pin location, at no extra charge. And, these pistons are lighter, use thinner rings, and have only 3.8cc valve reliefs, which will raise the comp slightly, which is good when using the 6x heads. That's the good news. The bad news is that they cost nearly $500 and because of their lighter weight, will require balancing the rotating assembly, even if you use the stock rods. I've used the SP pistons(back when they were still called TRW brand), with stock rods, without balancing.

http://www.ebay.com/itm/AUTO-TEC-SMALL-BLOCK-PONTIAC-400-428-455-FLAT-TOP-PISTONS-/261076439093?hash=item3cc95e5035:g:D0MAAOSwYlJW4Kyl&vxp=mtr

For an extra $112 you can go with the RPM bushed H-beam rods, and run the Auto-Tec pistons with floating pins. This assembly should be good to at least 7000rpm, should you ever wanna go that high. Hey, every upgrade costs more $$.

http://www.racingpartsmaximum.com/sae4340steelhbeam-2.html

Another piston option is the Icon IC890. They have a 1.720 pin height. If your measurement is accurate, these pistons might give you real close to zero deck height.

http://www.cnc-motorsports.com/icon-ic890-030-forged-flat-top-pistons-4-150-bore.html

But, most engine builders say you should have the decks machined square, before trying to achieve your desired deck height. Hey, the cost of an engine build just keeps going up, huh ?


"...I will start looking for some 6X heads..."

You can sometimes find 6x-4 heads for sale, over on the PY site. Here is the thread for a pair that apparently sold the same day the ad was posted.

http://forums.maxperformanceinc.com/forums/showthread.php?t=789467&highlight=6x-4+heads

The 6x-8 heads are more plentiful, but have bigger chambers, which will produce lower compression. The 6x-4 heads came only on 350's and W-72 400's. The 6x-8 heads came on all the other 400's from sometime in '75 thru '78. The 6x-8 heads can be shaved down to increase compression some.

Here's a set of 6x-8 cores, that can be picked up in Illinois, for $100.

http://forums.maxperformanceinc.com/forums/showthread.php?t=789883

Here's a bare set of 6x-4 cores, on CL.

http://sfbay.craigslist.org/eby/pts/5566946255.html

6x heads also come up for sale on Ebay. But MOST are WAY overpriced.

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2051541.m570.l1311.R1.TR1.TRC0.A0.H1.Xpontiac+6x+heads.TRS0&_nkw=pontiac+6x+heads&_sacat=6000

It costs almost $100 to ship a set of iron heads. So, it'll save the shipping if you can find some locally.




Edited by - Tub on 04 May 2016 3:09:20 PM
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Mordor67
Tribal Scout

22 Posts

Posted - 04 May 2016 :  4:27:18 PM  Show Profile  Reply with Quote
Tub,man, you are a wealth of information,as is this whole site, thank you. Got me convinced(from what I've read) to run steel rods and some forged pistons, not gonna cheap out. Car has a running 326 in it now so I can take some time to look for heads. The 140 heads off the 326 would be available to use too but dont know if its worth the money to put bigger valves and everything else in them.Would love to go with Edelbrocks but,$$$. Also,headers. Can I run headers with column shift AT?
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tjs44
Cochise

USA
412 Posts

Posted - 04 May 2016 :  5:14:37 PM  Show Profile  Reply with Quote
FYI,for a car that is 80-90% a street car headers are a PITA!You would be better off with the factory RA castiron headers.Tom
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Mordor67
Tribal Scout

22 Posts

Posted - 04 May 2016 :  7:16:45 PM  Show Profile  Reply with Quote
quote:
Originally posted by tjs44

FYI,for a car that is 80-90% a street car headers are a PITA!You would be better off with the factory RA castiron headers.Tom


that?s what it is. those aren?t exactly cheap
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tjs44
Cochise

USA
412 Posts

Posted - 04 May 2016 :  7:45:15 PM  Show Profile  Reply with Quote
Of course,better stuff is usually more expensive,same for headers.You can get cheap 3 tube heads or get custom made on the car so everything fits correctly.Your in a hobby that is not for the faint of wallet.Tom
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Tub
Sitting Bull

172 Posts

Posted - 05 May 2016 :  11:54:49 AM  Show Profile  Reply with Quote
I can definitely relate to a low budget build. Most every bracket car I've had was strictly low buck. But, I managed to have lots of fun and win lots of races, anyhow.

I don't know the answer to the column shift question. I do know that a conversion over to a ratchet type floor shifter would be a lot more fun.

I would assume that the cheap 3-tube headers mentioned, might provide more clearance and MAY clear the column shift linkage. And, although they get a bad rap, they will probably make more power than stock log manifolds. Hey, I have 3-tubes on my current '68 Bird bracket car. Why ? They were free !

Would expensive 4-tubes make more power. Probably would make slightly more. But, going just a hair quicker will not make a bracket car any more competitive. Most of our wins came in 12 sec cars. This one should run well into the 11's--7.50 or quicker in the 1/8 mile I'll be running. That's quicker than I have to be, to run the No-E footbraker bracket.

So, if painted 3-tubes is all you can afford, they'll make plenty of power for your street car. Even if you buy high dollar coated 4-tubes, the mufflers and the rest of the exhaust system will be the choke point, therefore negate most of the performance advantage of the better headers. IMO

If you'll check around, you may be able to find some used 3-tubes, real cheap. New ones are over $200.

A quick search turns up the best price from jet.com @ $216 shipped. They show the wrong picture. But the part # and description are correct. And if it's your 1st order from them, you get $30 off that price.

https://jet.com/product/detail/f400ef49d68d40e2b4642c334cebc55d?jcmp=pla:ggl:all_products_catch_all:lm_catch_all:na:na:na:na:na:2&code=PLA15&ds_c=All+Products+Catch+All&ds_cid&ds_ag=LM_Catch+All&product_id=f400ef49d68d40e2b4642c334cebc55d&product_partition_id=163791601980&gclid=CjwKEAjw3qu5BRC-0uCw8O6Y5zcSJAA_WtdLiWnJ9TGWmDFHnB-aPDrzXA3rI-5TLIu1yGBPd7wy-BoCRA3w_wcB&gclsrc=aw.ds

They're $223 shipped from an Ebay store.

http://www.ebay.com/itm/Hedman-28140-Painted-Exhaust-Header-Tube-Size-1-5-8-2-Coll-3-Pontiac-326-455/161258826046?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20131003132420%26meid%3Dfa3e77d7af824020bbd5245c16365ae9%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D201195428202

Amazon also has similar prices. And Summit will usually match most prices, if you prefer to buy from them.

http://www.amazon.com/gp/product/B000COD2D6/?ie=UTF8&me=ATVPDKIKX0DER

You can go to this link, then click on your body style and see if they will work with your column shift. The one I checked said yes.

http://www.hedman.com/site/?d=119&dt=108&Keyword=7

Edited by - Tub on 05 May 2016 12:06:23 PM
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cortcomp
Coyote

USA
5338 Posts

Posted - 05 May 2016 :  3:45:47 PM  Show Profile  Visit cortcomp's Homepage  Reply with Quote
I remember being over at PY i think, and guys were running in the 10's on stock logs. Not RARE manifolds, which supposedly flow better than shorty headers, but honest to god cleaned up logs. Don't hold me to it, food for thought.
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Tub
Sitting Bull

172 Posts

Posted - 05 May 2016 :  10:46:41 PM  Show Profile  Reply with Quote
"I remember being over at PY i think, and guys were running in the 10's on stock logs..."

Yeah, here's one reference to it.

http://forums.maxperformanceinc.com/forums/showpost.php?p=5227634&postcount=20

Here's what Cliff posted about the car, on his web site.

"...Just got an email yesterday from my good friend and customer Jay Delaigle. His 74 Pontiac Firebird is pictured on our website.

It's a legal FAST class car, using crappy Pontiac 4X heads, EGR iron intake, Q-jet, and "log" exhaust manifolds.

He went 10.89 @ 125mph yesterday.

The must run on 7" wide bias ply tires.....just amazing.

My contribution to the project are the carburetor, distributor, and transmission......Cliff"

Here's some details. Not exactly a low budget build. And the logs are highly modified.

http://www.sdperformance.com/customerCars_01.php?carID=258

Edited by - Tub on 05 May 2016 11:31:25 PM
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cortcomp
Coyote

USA
5338 Posts

Posted - 06 May 2016 :  10:15:56 AM  Show Profile  Visit cortcomp's Homepage  Reply with Quote
Oh i'm sure they're worked over logs. My point being, IMHO, 99% of cars with headers add 0 power or gain almost nothing, because they're driven on the street under 2500rpms all day and aren't built to take advantage of the flow. Why bother with the hassle? I know a lot of them are installed because a lot of weekend enthusiasts can bolt them on and go, but they're afraid to mess with camshafts, gear sets, etc that really will give some kind of result. It makes them feel like they're doing something to go fast. Whether it works or not doesn't matter, helps our hobby go around, spending money.

And if you feel exhaust is limiting you on the street, i feel RA cast headers are the best of both worlds. Personally, only reason i'd deal with headers would be: LS swap if i can't get manifolds to work, or race car. And, personally, i find them ugly. Rarely do they stay nice.

But, i'm a guy who loves the OEM look, so spark boxes, an fittings, serpentine drives, all kind of stick out to me. To each his own. I was just pointing out, for a mild street build, i wouldn't fuss with headers.
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Steve C.
Crazy Horse

1677 Posts

Posted - 06 May 2016 :  10:33:30 AM  Show Profile  Reply with Quote
Jay Delaigle's car. Yes, highly worked over with big bucks involved. Same with the intake manifold.

EXHAUST MANIFOLDS- 1974 Pontiac Log manifolds #490142/490143,Port matched,transplanted exits from RA III
Manifolds(2.45" exits),extrude honed, directional work and flowed by Gessler head porting.

Edited by - Steve C. on 06 May 2016 10:47:33 AM
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Steve C.
Crazy Horse

1677 Posts

Posted - 06 May 2016 :  10:46:39 AM  Show Profile  Reply with Quote
For interest, and a fwiw for conversation here. And no suggestion it applies here for this specific combo in the thread.....

On this engine before the article was written they did some testing with a smaller cam and RA manifolds.

http://www.hotrod.com/how-to/engine/hppp-0901-474ci-aluminum-head-engine-build/

The RA manifolds knocked about 80 hp and 55 ft.lbs torque out of the engine. I will presume these numbers were at peak power rpm and peak Tq rpm, therefor as suggested it would be less impact at a lower street rpm.

Edited by - Steve C. on 06 May 2016 10:51:02 AM
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Steve C.
Crazy Horse

1677 Posts

Posted - 06 May 2016 :  11:31:04 AM  Show Profile  Reply with Quote
Headers vs. Manifolds - Ferreting Out Fumes

http://www.hotrod.com/how-to/engine/hppp-0312-headers-vs-manifolds/
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Blued and Painted
Chief PONTIAC

USA
3409 Posts

Posted - 06 May 2016 :  9:22:40 PM  Show Profile  Reply with Quote
quote:
Originally posted by tjs44

FYI,for a car that is 80-90% a street car headers are a PITA!You would be better off with the factory RA castiron headers.Tom

X2
-- http://www.hotrod.com/how-to/engine/hppp-0312-headers-vs-manifolds/ --


Bull Nose Formula/ 461/ Q-Jet/
TH400/ 3.08 8.5 / R44TS.
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Mordor67
Tribal Scout

22 Posts

Posted - 19 May 2016 :  06:05:04 AM  Show Profile  Reply with Quote
what do you think of this kit from Summit?http://www.summitracing.com/parts/fem-csmhp742-400/kitcombocontents. Taking the block to mach shop today.
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tjs44
Cochise

USA
412 Posts

Posted - 19 May 2016 :  10:12:50 AM  Show Profile  Reply with Quote
If you deal with anyone at Summmit make sure you ask for Scott Esterly!He is a pontiac owner and racer.Tom
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Mordor67
Tribal Scout

22 Posts

Posted - 21 May 2016 :  12:36:24 PM  Show Profile  Reply with Quote
quote:
Originally posted by tjs44

If you deal with anyone at Summmit make sure you ask for Scott Esterly!He is a pontiac owner and racer.Tom

Thats good info, thanks!
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Mordor67
Tribal Scout

22 Posts

Posted - 28 Jan 2017 :  08:53:43 AM  Show Profile  Reply with Quote
Well, update on the 400. Wasn't as good as I thought as we had to turn the rod journals .010 and bore it .030 over. Went with the forged pistons and RPM rods. Looked around for some different heads but I decided to just run the small valves for now, with the Summit 2801 cam. This is a fact A/C car and really just a cruiser. Just gonna run the factory logs and see how she does- and hope its happy on 93 octane...
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Mordor67
Tribal Scout

22 Posts

Posted - 07 Jun 2017 :  3:33:35 PM  Show Profile  Reply with Quote
Its done, it runs! Got it fired up over the w/e. Got a little hot during the break in 220+ so we shut it down for awhile. Got it running again and it still was staying between 200-210 the whole time. Could hear the clutch fan kicking in so that seems good. Also, I reused the old water pump as it seemed good; no noise, cast impeller ,etc. That was a mistake as it leaked out of the weep hole but then stopped. Anyway, cant trust it and new one on the way. The rad is the original Harrison re cored about 5 yr ago. The 326 always ran on the hot side and I wonder if its this rad. I did clearance the divider plate on this wp and this new motor has the 11 bolt pump so was hoping my overheat prob would go away. See how it does just driving around.
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cortcomp
Coyote

USA
5338 Posts

Posted - 07 Jun 2017 :  3:43:50 PM  Show Profile  Visit cortcomp's Homepage  Reply with Quote
What's your initial timing? If it's near 8-10, try near 15 and see if it cools down.
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Mordor67
Tribal Scout

22 Posts

Posted - 07 Jun 2017 :  3:54:14 PM  Show Profile  Reply with Quote
Yeah, when we were breaking in it was around 25 deg or so at 2500. I was just stoked it fired almost immediately on initial start up. Got lucky the timing was that close.
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cortcomp
Coyote

USA
5338 Posts

Posted - 07 Jun 2017 :  4:29:49 PM  Show Profile  Visit cortcomp's Homepage  Reply with Quote
What is it at idle? You'd want to me like 32-35 when all in IIRC? I put a fresh 455 together and it ran warm. Upped the initial timing and it cooled right down. I'm a big believer in getting all the timing you can now.
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Dweld02
Tribal Scout

8 Posts

Posted - 07 Jun 2017 :  11:21:59 PM  Show Profile  Reply with Quote
Great resources Tub! Thanks
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Mordor67
Tribal Scout

22 Posts

Posted - 08 Jun 2017 :  10:25:40 AM  Show Profile  Reply with Quote
quote:
Originally posted by cortcomp

What is it at idle? You'd want to me like 32-35 when all in IIRC? I put a fresh 455 together and it ran warm. Upped the initial timing and it cooled right down. I'm a big believer in getting all the timing you can now.


When I get the new water pump in I can get a better tune on it. Think initial timing about 15 deg now
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Mordor67
Tribal Scout

22 Posts

Posted - 12 Jun 2017 :  07:41:24 AM  Show Profile  Reply with Quote
Well, after bringing home the IR thermo gun from work, this motor is running about 12-15 degrees cooler than the stupid electric aftermarket gauge says. Which is good news but now I got to get a better gauge. The ones I put in there are VDO's so its not like they are the cheapest thing you can buy. Probably get a mechanical one this time; dont know if they are any better or not
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Dweld02
Tribal Scout

8 Posts

Posted - 13 Jun 2017 :  01:12:35 AM  Show Profile  Reply with Quote
My impression is mechanical ones are better.
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Mordor67
Tribal Scout

22 Posts

Posted - 13 Jun 2017 :  5:26:15 PM  Show Profile  Reply with Quote
Got a SW mech one on the way
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tjs44
Cochise

USA
412 Posts

Posted - 13 Jun 2017 :  7:30:10 PM  Show Profile  Reply with Quote
Check it with your gun also!Never know until you do.Tom
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Mordor67
Tribal Scout

22 Posts

Posted - 08 Aug 2017 :  12:40:46 PM  Show Profile  Reply with Quote
The SW gauge reads about 10 degrees to hot too. This IR gun is calibrated so I assume that it's correct. Checked it on my buddies car and his gauges are cheap parts store junk and his temp gauge was closer to right than these brand names are
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cortcomp
Coyote

USA
5338 Posts

Posted - 08 Aug 2017 :  12:54:13 PM  Show Profile  Visit cortcomp's Homepage  Reply with Quote
Might be where you're checking it is hotter than where the sender is? Just a guess.
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Mordor67
Tribal Scout

22 Posts

Posted - 12 Aug 2017 :  12:29:55 PM  Show Profile  Reply with Quote
Pointing right at the sender, manifold crossover, rad, etc. Can't see why they would be cooler than the coolant?
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DanM
Buffalo

80 Posts

Posted - 22 Aug 2017 :  5:12:54 PM  Show Profile  Reply with Quote
The sender/manifold crossover will be cooler than the coolant because they are on the outside. The coolant is on the inside. The outside is always cooler than the inside. Heat goes from hot to cold; from inside to outside.

Believe your temp sensor.




71 LeMans Sport Convertible with 310,000 miles driven year round since 1994.
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DanM
Buffalo

80 Posts

Posted - 22 Aug 2017 :  5:37:12 PM  Show Profile  Reply with Quote
Headers are Badass!

But seriously, if you want the all stock look headers are in my book "all stock" just like my AM/FM converter is. My car came with AM radio. 40 years ago the original owner got an FM converter. Anyone who sees it admires that as much as any OEM part. Headers are old fashioned, made for big engines with tons of space in the engine bay.

As I've suggested elsewhere, get Doug's and pay someone else to intall them. They come with a label-plate like Tiffany jewelry.

Regarding HP gains. Tub, I think you posted a link to a hot rod article. I read that many moons ago and it's one of the best articles out there using a dyno.

My take away from that article: if you have a big engine with a big cam and big heads you will gain 40 HP with headers vs poorly designed manifolds. Pontiac RA manifolds will get you half that at half the cost and half the install pain.

I did dyno testing of my car a half dozen times with different improvements. My headers were worth 20 HP (255 went up to 275). But any further work done to my engine I can get another 10% bonus due to the headers (purely estimates based on instinct.)

But more important than all that, they sound different than manifolds. You might like the crisp sound they give, you might not. For me, a daily driver, the sound is everything. I have big mufflers to give a broad sound that's not loud. (The Jim Hand recommended mufflers.)

I also don't have an X-pipe. That colors the sound of the exhaust. It gives it a rhythm like a dual-kick bass-drum played by Neal Peart.

Meahwhile the engine firing order is such that it goes (Driver side (D), passenger side (S)) D S D D S D S S D S D D S D S S... So if you run true dual you get out of a single pipe D _ D D _ D _ _ D _ D D _ D _ _ D. Notice that's not a smooth D _ D _ D _ D _ D _ sound. So you hear the "skip" at 1/8th the rate you would hear the exhaust with a cross over. At cruse that's about 15 Hz.
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