puttin on a header

[pepboyspecial]

Hey guys, i'm a noob with a '74 620 and slowly realizing this datsun stuff is just as, if not more addicting than small block chevy's and minibikes. I just a got a short tube header and a turbo muffler for the l18 that's in it, and i was wonderin what all can i shitcan? its smog exempt so i was thinking to make a block off plate for the EGR stuff to clean up the underhood, only thing is that the crank vent tube goes to the PCV valve which is in that mess on the side of the intake manifold. Can i just put a breather filter on that crank vent tube? Also there's a line that comes from the gas tank to EGR stuff, is it ok to put like a vacuum cap on that line or is that a deal for venting the tank? And last, and i gonna lose any power? I'm still new to all of this and the forums so these are probably redundant questions lol...

[ggzilla]

Yes you will lose a little power with the header, but it will sound 10x better, so don't worry about it.

 

Leave the crankcase breather systems alone (PCV and breather hoses).

Leave the fuel tank vent system alone. It has nothing to do with EGR.

[Ron1200]

The 620 I have came with headers, 2" exhaust and a Flowmaster muffler. I was a bit too loud for me (especially when I drove it into the parking garage at work). I added a resonator (looks like a glass pack) in front of the muffler. That change removed the raspy-ness and reduced the 'drone' on the freeway. But maybe you want raspy. :)

 

It still sounds 'sporty' enough that I'll run it through the gears for an Auditory Fix. :)

 

There is also an exhaust thread in the Engine section of the forum...LINK

[Z-train]

The factory manifold you have is better than ANY header.For a street driven truck,the header will cost you HP.Getting rid of the EGR will gain you nothing.You are Emissions TESTING exempt-NOT exempt from having the SMOG gear on the vehicle.Plenty of good mufflers out there,however,Flowbastards aren't one of them.

[Ron1200]

Plenty of good mufflers out there, however,Flowbastards aren't one of them.

 

Just curious... I didn't buy the Flowmaster, so no 'defensive feelings' here...

Please elaborate... What keeps Flowmasters off your list of good mufflers?

 

From the engine thread I linked... " Flowmaster (lots of R&D, decent flow, and average price with decent quality)"

[banzai510(hainz)]

flowmasters =Lame

 

a 74 manifold might be fine

[KC Phirus]

No muffler is best muffler.

Depending on your state laws and the tolerance of your neighbors.

BRRRRR *REV* BLAPBLAPBLAP BRRRRRR

Somethin like that

[Ron1200]

flowmasters =Lame

 

a 74 manifold might be fine

 

 

This comes across as opinion (which we all have :) )

I was looking for an explanation... of why Flowmaster is better or worse that others.

An opinion can be broken into areas of satisfaction/dissatisfaction... some areas are more important than others to the purchaser... everything is a compromise.

 

Like (order is determined by purchaser)

Price

Durability

Sound

Performance

 

If they 'suck'... why do they suck? Your opinion is valuable, I just wanted to know your criteria.

[DanielC]

This is my opinion on why a Flowmaster muffler may not be the best muffler. The cost To make a muffler, any brand, is basically materials to make it, the labor to make it, shipping costs for the materials to the factory, and shipping from the factory to the auto parts store, where you pay your hard earned money for it. I may have left some things out, but so far, I am talking just amount the costs any manufacturer of mufflers has to pay.

 

There are several brands of mufflers for sale. Every muffler company is competing against every other muffler company for your dollar. That keeps the prices of all mufflers about the same.

 

If you see a Chip Foose, or a Don Gartlis promoting a brand of muffler, you can bet your next paycheck they are being paid to promote it. If the muffler company is a major sponsor of a Saturday morning auto show on TV, you can bet the muffler company is paying a lot for their ad the show, and possibly have their muffler featured in the "How to add dual exhaust to your 1964 GTO" segment on the show.

 

So you are either going to have to pay more to get the same quality and workmanship in a heavily promoted muffler, or you can pay less for another quality muffler that may have better materials in it, but no hidden cost of promotion.

 

I almost forgot, The stock L-16 exhaust manifold is about as close as you will find to a "cast iron header" on any engine made, probably even with modern engines. It fits, does not leak, is not excessively noisy, and goes a very good job of helping the engine get rid of exhaust. About the best thing you can do is to extend the two outlets on it several inches before joining them into one pipe, and then having a larger about 2" pipe from there, out to a baffled genuine turbo muffler, and then out the back of the vehicle. but make sure it is a turbo muffler, not a muffler with the word "turbo" on the box.

[ZackTheImpaler]

^ Exactly what he said to the T

 

 

Including pick up the L16 mani.

[banzai510(hainz)]

Flowmasters will rot out from the inside right where you can see the plates that they weld in.

 

They now have a stainless version.

 

My Next muffler will be a Cherrybomb Turbo 2 or a Thrush Turbo(dynomax bought out Thrush) in a small case size. Maybe adding a resonater

 

most I see are 2 chamber but if theres a small size 3 chamber I would get that one as I hate noise now on long trips. When I was younger Im sure a Cherrybomb glasspack would be fine.

 

But a better one might be a SuperTubro from Dynomax. I have one on my 521 and been there almost 8 or 9 years.

 

 

Alot depends on Intake also. If one has dual carbs all the mufflers mentioned would sound good. Just sometimes a tiny stock carb with a BIG MUFFLER will not sound right.

 

 

I almost thought tose Monza/Anza mufflers sounded cool also but they dont last either.

 

 

Its alright if you buy a Flowmaster. Its your money.

[datzenmike]

Now the taste test... can you tell which one is butter??? I dare anyone to find more than a couple of hp on a stock engine between these two setups. Lets see... stock is free. Header is a hundred bucks per horsepower gained?

 

 

 

 

 

Two different styles...

 

Later L18. Note the EGR tube.

 

 

Most of the gains from a header are overcoming truly crappy stock manifolds. Fortunately for us the L series L16/18s were superb to begin with so gains will be vanishingly small.

.