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-   -   are 1 5/8 long tubes too small for a 414 ci small block? (http://www.hotrodders.com/forum/1-5-8-long-tubes-too-small-414-ci-small-7152.html)

tony350ss 03-15-2003 04:55 PM

are 1 5/8 long tubes too small for a 414 ci small block?
 
i am putting a 414 small block stroker in my s10 blazer. the only resonably priced longtubes come in a max 1 5/8 with 3 in collector size. there are also some 1 3/4 inch sanderson headers, but they are shorties. which ones should i go with? will these be too small for my engine? i plan to go with AFR 195 heads, an rpm airgap intake and a modified 750 double with proform body(about 800 cfm. compression will be 10.5:1, and i was looking at a solid lift comp cam. dur at .050 250 int and 260 exh.


also, hooker makes some 1 5/8 as well with equal length tubes, but they wrap around the frame rail(limited turning radius), and are a huge pain in the *** to install. do you think it is worth the extra troubles, and worth giving up some turning radius for equal lengths?

thanks alot

Super Streeter 03-15-2003 05:10 PM

The 1 5/8" headers are a bit small for a 500 horsepower engine.They can work,but figure that if the engine would have made 500 hp with the correctly sized 1 3/4" headers you might be down about 20 or so hp with a set of 1 5/8" headers.I would go with the sanderson shorties.I know of a few guys who have gone in the 10's with the hooker 1 5/8" Hooker swap headers,but they knew they were throwing power out the window.Good luck.

tony350ss 03-17-2003 08:09 AM

would anyone else take the 1 3/4 shorties over the 1 5/8 long tubes?

1BAD80 03-17-2003 08:12 AM

I agree with Super Streeter the shorties have a 2 1/2" outlet flange. You need the flow to use the power in the motor that you built.

4 Jaw Chuck 03-17-2003 08:29 AM

Not me, resonance in the small tube will be far more beneficial than the large tubes. If you did an area under the curve for your engine with both types I would imagine you will see that the long tubes low rpm advantage extends far enough into the intermediate-upper rpm range that you end up being farther ahead. Depending on the short tubes length you may never realize any resonance tuning at all until stratospheric rpm levels like 10 000 rpm!

Shorty headers are OK for flow but resonance tuning is why you install a header, actual flow numbers are only a small part of a headers function...also 1 5/8 is not that small...we are talking an 1/8 of an inch here folks? :confused:

Equal lengths ensure that any tuning that results occurs at the same point in the rpm range on all the cylinders, it is definetly a goal worth pursuing as it concentrates the resonance bump in the power curve instead of spreading the resonance "zone" across the rpm range....but...if the difference in length is a couple inches at best then I doubt you would see much difference.

I say go for the unequal length 1 5/8" and enjoy your truck and it's unimpedded turning circle.

This will be a street vehicle right?

tony350ss 03-17-2003 08:38 AM

thanks 4 jaw, thats exactly what i wanted to hear.
i am not a serious racer, but this will be primarily a strip truck. i am building it to take to the track and have fun with. if i win a few bracket races, great, if i dont, thats fine to. i will only drive it every now and then on the road. i wont be able to afford gas if i drive it everyday. it will be driven at least once or twice a week tho, and it will be driven to the track.

i need all the help i can get with the steering, because i installed a manual steering box for simplicity, so i think i will go with the hedmans.

TurboS10 03-17-2003 11:21 AM

Well said 4 Jaw.

Too many people become caught up in the peak HP number. Well, if everything up to that peak number is lower, then the car will be slower.

This is not only due to the scavenging of the longer tubes, but he gas velocity. Also, If the tubes are too large, low end will suffer. Yeah it will make a bit more power up top, but how much time does it spend there. On the track...probably less than 2 seconds. On the street...well it really never should. The majority of the work is done at below peak power. If power is higher in this range, performance will be better.

Chris

1BAD80 03-17-2003 11:28 AM

After reading what 4jaw stated it makes a lot of sense. I stand corrected. Hes da man. :D
Chris has a good point also. :)
1 5/8" headers.

chrismac 03-17-2003 11:45 AM

It depends on what size exaust port it is


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