[70 lucerne lemans]

I agree with bman,unless your going to the track regularly you will never know the difference.Im running the 2.5" ra manifolds and am running high 12s,now Im going to get a set of dougs because I want that extra tenth or two.I doubt my but dyno would know the difference between a 12.5 and a 12.8,my timeslip does!

[aj66gto]

Hi.

I really got some good advice from you guys.

OMT, I read your post. But I thought you were leaning toward the headers.

At this point I have to agree with B-Man. I 'll put the original manifolds back on and break in the cam. I'm sill at least 6 months until I get the body back on the frame. I may have gotten too excited about finishing the frame and jumped the gun some. And I could put the $$$ toward a 200R4 tranny.

I still need to decide of what I will do in the end. But, like B-man say's...Sometimes you want what to want, because you want it. So a set of Dougs might be in there before the fenders go on.

Is there a difference in the sound of a Ram Air manifold and headers?? Or is just a muffler choice.


Thanks to all,
Anthony

[Tom Hand]

Anthony, the headers will tend to ring and ping a bit more if you know what you are listening for.

Sound out the rear? With a milder cam, doubtful even the most trained ear can really tell the two apart unless you run dastardly loud mufflers on it.

Like many others, I would suggest you use good manifolds if you never plan to race and worry about that last 7 to 12 HP peak you might see between headers and them.
Tom

[aj66gto]

Hi,

Do I have to look on E-Bay or swap meets for a set of Ram Air manifolds or is there a place that repo's them. Are there differents types? Having the stock 093 heads what will I need?

Thanks,
Anthony

[pro-tour79]

check PY for R/A manifolds

[Goin' Topless]

Having used both on the same car, I can say the the HO manifolds are quieter, yet make a mildly modified/stock engine feel more "peaky" in the powerband.

With headers, you'll feel a moderate difference at lower speeds. You'll feel solid torque there. At high speeds, I doubt you'd be able to tell any difference unless you're at a race track.

One more thing about sound...the manifolds channeled more sound to the back of the car compared to headers. I remember getting a harmonic every now and then around 35-40 mph with manifolds that wasn't there before with headers.

Other than that, if performance isn't a huge priority then go with manifolds. You can always put em in later if you want 'em.

[Tom Hand]

Anthony, you might consider investing $18 in this book, sold here by PY. It has many photos and details you need to know about manifolds, headers, and mufflers. The exhaust section covers in pretty good detail all of the things you'd like to know and there are good photos too.
http://216.178.81.107/iwwida.pvx?;it...0%201?comp=py1

[aj66gto]

Tom,

I bought your book about a month ago. It was alittle much for me as a beginner. I've come to understand it better as I learned more about this stuff. Like you said I would.

I started to read the exhaust section last night, but my girl had other things in mind.

I will read it later.

Thanks,
Anthony

[bmpmdf]

I don't think anyone has done more testing in this area than the Hands. Tom, I will need to get hold of you in hopefully a month to see how interested you would be in helping with a set of headers for a Pontiac powered S-10. (I did a little trading today).

[aj66gto]

OK..

Last night I read the exhaust section of Tom's book. (Chapter 8)

It was good reading and had alot of info packed in the pages. Although I do have some questions.

Inches of water means backpressure..Right? I'm guessing that the meter reads backpreasure in inches of water. The more inches of water the more backpressure on the engine.

Also on pp 106, you have a chart that highlights the airflow, and sound level of different mufflers.

Am I right to assume that the scale goes from 0% to 100%. 0 being no air flow or no sound and 100 being no restriction on flow and max sound.

Using that scale what do you think is a good value for sound. I see that most are 90 and above at 3500 rpm. Even the OEM are 88 and 90. The air flow is plain to see. Closer to 100 the better.

I also like the test that shows the further back the muffler is the better the air flow is due the heat loss.

Would I be correct in saying that a smaller muffler would flow better, because of the extra pipe to get to the muffler. thus allowing more cooling time? Not that it will matter in my car, but maybe in a higher HP engine.

Through the reading, and advice I received on this site. I think that the Ram Air manifolds will be great for my needs. I did not know that the manifold had interior runners that separated each cylinder. You can get a manifold with a 2.5" outlet also. Thats .25" bigger than the original. Then you go out with 2.5" pipe all the way.

I feel with the Ram Air manifolds and an X-pipe I'll be fine.

Thanks,
Anthony

PS. With a foot of snow on the way, I'll never get the engine on the frame.

[WCWhitey]

Anthony, like we discussed the other night, I agree with B-Man on the log manifolds, if you want to see how the set-up looks and sounds in the 66 come take a look. I have the Pypes 2 1/2" setup with the "X". My car has no breathing issues and sounds great. If you don't want to go with the logs, go with the R/A's or Longbranches, way cleaner setup, nice sound and little to maintain and there will be a power increase. No argument that a good set of headers will let you squeek out some extra power, but in my opinion are a big PITA. Just wanted to get my vote in! Bill

[WCWhitey]

Oh, you can put the engine on a sled to get it from the shed to the garage, LOL Bill

[aj66gto]

Thanks Bill...I thought about it... A sled with a tire on it might work.

I really though headers were the way to go, but now looking, I have to agree with you.

I'll have to hang on to your leveler maybe a week or so...And I would Love to take a look at yours when you gety some time.

Anthony

[Tom Hand]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Last night I read the exhaust section of Tom's book. (Chapter 8)
<span class="ev_code_RED">Thanks Anthony </span>
It was good reading and had alot of info packed in the pages. Although I do have some questions. <span class="ev_code_RED">Ready to answer!</span>

Inches of water means backpressure..Right?
<span class="ev_code_RED">It is a way to measure pressure and in this case, yes, we used it as the measure of how much resistance the exhaust system or mufflers had to gas flow. </span>

I'm guessing that the meter reads backpreasure in inches of water. The more inches of water the more backpressure on the engine.
<span class="ev_code_RED">Yes and remember, most of the good mufflers are pretty darn high flowing.</span>

Also on pp 106, you have a chart that highlights the airflow, and sound level of different mufflers.

Am I right to assume that the scale goes from 0% to 100%. 0 being no air flow or no sound and 100 being no restriction on flow and max sound.
<span class="ev_code_RED">You may be confusing two things. I do not have my copy here but sound levels are measured in dBAs. Airflow was listed as a percentage of flow related to an open pipe. Higher dB values are louder.</span>

Using that scale what do you think is a good value for sound.
<span class="ev_code_RED">The lower the better in my book. </span>

I see that most are 90 and above at 3500 rpm. Even the OEM are 88 and 90. The air flow is plain to see. Closer to 100 the better.

I also like the test that shows the further back the muffler is the better the air flow is due the heat loss.

Would I be correct in saying that a smaller muffler would flow better, because of the extra pipe to get to the muffler. thus allowing more cooling time?
<span class="ev_code_RED">No, that is not a fair statment. The larger mufflers tend to flow more air DEPENDING upon how they are made. </span>

Not that it will matter in my car, but maybe in a higher HP engine.

Through the reading, and advice I received on this site. I think that the Ram Air manifolds will be great for my needs. I did not know that the manifold had interior runners that separated each cylinder. You can get a manifold with a 2.5" outlet also. Thats .25" bigger than the original. Then you go out with 2.5" pipe all the way.
<span class="ev_code_RED">Yes, and that is why in this case, the larger manifolds may be the hot ticket for you now and when you step up to more power someday.</span>

I feel with the Ram Air manifolds and an X-pipe I'll be fine.
<span class="ev_code_RED">I agree!</span>

Thanks,
Anthony

PS. With a foot of snow on the way, I'll never get the engine on the frame.
Bummer man!
</div></BLOCKQUOTE>

[tremo]

Excellent thread...learned a lot! In looking at my PY catalog (pg. 4-56) I see two types of manifolds:

RPE650H 1964-72 RA Manifolds 2-1/2" ($399)
RPE652 1968-72 D-Port Manifolds 2-1/4" ($369)

Can I assume the 2-1/2" RA manifolds will work on D-port heads as well? I assume the only real difference is the outlet size (and the price!)??

The real question is, will the 2-1/2" RA manifolds bolt up to a 350ci with stock #47 heads or will I need to have extra holes drilled/tapped? I read in another post that the driver's side has 5 bolts and the passenger side has 4. Is this the same for all heads? (Got a heat shield blocking the manifold on the driver's side so I can't tell).

Thanks!

Jim.

[b-man]

You will need to have the end holes tapped on your heads. Otherwise there is no way to properly seal the manifolds to the heads.

One side will have only two bolts, the other only three. Not enough to work without leaking.

[tremo]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by b-man:
You will need to have the end holes tapped on your heads. Otherwise there is no way to properly seal the manifolds to the heads.

One side will have only two bolts, the other only three. Not enough to work without leaking. </div></BLOCKQUOTE> Thanks b-man. Had a feeling. Do you mean one side will only have two bolts that will line up and the other side three?

Thanks,

Jim.

[b-man]

The RA manifolds due to their free-flowing design only have 4 and 5 bolt holes available to hold them on.

Unless all 6 holes on your #47 heads are tapped, they won't work with the RA manifolds. All the bolt holes will line up, its just a matter of all of them being tapped for bolts.

Many lower-performance heads starting in '69 only had 4 holes tapped, the outer 2 were not needed for the standard exhaust manifolds.

[tremo]

Ah, thanks! Hmmm...so since the holes are pre-existing on the head, can I assume I can either have the holes tapped without removing the heads (which I'd prefer in my situation) and/or tap them myself?? If so, I may also go with the RA manifolds and reuse them when I build a 400ci...

Thanks again!

Jim.

[b-man]

If all 6 holes are there, then they are already tapped. The factory didn't drill the holes without tapping threads in them.

Lots of heads in '69 had all 6 holes tapped, but only used 4-bolt log exhaust manifolds. Go figure.