Hot Rod Forum banner

Ram horns vs block huggers

20K views 29 replies 16 participants last post by  bygddy 
#1 ·
I realize this question has been asked many times before (I did use "search") in different shapes and forms but my application is somewhat specific. I am swapping a sbc into a tight engine bay, and I have to decide between exhaust manifolds or block hugger style headers. Long tubes are definately not an option. The headers I am interested in are part # H8052 from Patriot Exhaust. They are quite short, measuring only 6" from top of exhaust port to bottom of flange, and have 1-5/8" tubes. The ram horns would be the 2-1/2" version. The application is strickly for the street, in a 3100 lbs car with regular gears and a T5 trans. The engine is a 350, nothing special, 10:1, iron heads with a cam and Holley 750 DP one a single plane manifold. I kind of like the advantages of the ram horns (flow quite well, quiet and long lasting) compared to headers. Since I wont be revving this engine to the moon probably 5500-6000 rpm max, would I really get that much more power with block hugger style headers? Any comments or advise would be greatly appreciated.
 
#2 ·
I believe tube headers- even shorties- will make more HP than rams horns. Even at your performance level.

How much more, I can't really say.

If it were me and I already had the OEM's, likely I'd go ahead and use them.

On the other hand if I had to buy on or the other, shorties would get the nod.
 
#5 ·
My engine builder swears that the rams horn manifolds are much better on the street than any shorty header. He claims that when you switch out the ram horns for shorty headers, you typically lose 15-18 HP. He's been building performance street engines since 1962 - I tend to trust him.

Just my $.02

Joe G.
 
#6 ·
You know, some people go there whole lives doing things the wrong way and assume that since it has worked for 70+ years it must be right... Experience never directly equates to knowledge and understanding. (experience proved the world was flat for a LONG time to put things in perspective)

Rams horns are perhaps the best manifold out there, but there are some pretty good shorty headers out there too that are WAY better than ram's horns. I'm not a fan of block huggers and would probably use the RH's just for the ease, but a good set of shorties would be the best bet for power and space constraints.
 
#7 ·
Are you talking about stock cast ram's horns here or a ram's horn design of header? I know the guys at our track like to try and find the cast rams horns but others swear they are hardly worth the trouble over the run of the mill cast small block manifolds. I can't imagine a well designed header ever being worse than a cast manifold. Maybe the problem with the shorty is that the tubes are unequal length but that should be more of a problem in the rams horn.
 
#8 ·
speede5 said:
Are you talking about stock cast ram's horns here or a ram's horn design of header? I know the guys at our track like to try and find the cast rams horns but others swear they are hardly worth the trouble over the run of the mill cast small block manifolds. I can't imagine a well designed header ever being worse than a cast manifold. Maybe the problem with the shorty is that the tubes are unequal length but that should be more of a problem in the rams horn.
I was referring to the stock 2-1/2" ram horns. Dorman makes them for not too much $$. I don't know about the quality though. As for the shorties I was thinking of, they are unequal length tubes but they are 1-5/8" diameter.
 
#10 ·
speede5 said:
Maybe the problem with the shorty is that the tubes are unequal length but that should be more of a problem in the rams horn.
I'm w/you on both. Also the shortys have no collector and have an immediate down-turn to the primaries, hurts flow.

There are shortys and there are block huggers, Some shortys may be better than block huggers, but neither are as good as full length, equal length headers, IMHO.

When I say shortys in this thread, I'm referring to block huggers, as the OP had mentioned.

Sorry if this caused any confusion. Here on, I will differentiate between the two.

And again I will say that any decent tube header, shorty, hugger or other, should out perform a cast iron OEM SBC manifold- log or rams horn. And I personally believe the rams horn to be better flowing than a log.
 
#11 ·
ap72 said:
You know, some people go there whole lives doing things the wrong way and assume that since it has worked for 70+ years it must be right... Experience never directly equates to knowledge and understanding.
that is quite possibly one of the best things I've heard in a long time. x2.

With few exceptions, the worst headers will make make better power than the best manifold. I agree there are some terrible shorties and some great manifolds that don't fit the description, but its pretty safe to assume that any headers are better than ram horns.
 
#13 ·
Block huggers are better than ram horns for making power. I would guess they are worth around 20 or 25hp on a 350 that makes peak power in the 5500 rpm range.

Plus block huggers fit in tighter compartments than ram horns.

The down side is headers tend to have more gasket leaks and are louder.

Furthermore, Block huggers are especially tough on gasket at the 3 hole collector flange. So, use a composite gasket there (not a white paper gasket).

Finally, the other issue with block huggers is it is tougher to get the bolts in and tighten up (at the head and especially at the collector). Take it from experience, use a high quality, zinc coated grade 5 bolt at the collector flange, don't use stainless as they tend to cross tread when you tighten them which makes it real tough to get them off. you will need to use header bolts (7/16 headed 3/8-16) for the header to head fasteners.
 
#15 ·
mrl said:
I realize this question has been asked many times before (I did use "search") in different shapes and forms but my application is somewhat specific. I am swapping a sbc into a tight engine bay, and I have to decide between exhaust manifolds or block hugger style headers. Long tubes are definately not an option. The headers I am interested in are part # H8052 from Patriot Exhaust. They are quite short, measuring only 6" from top of exhaust port to bottom of flange, and have 1-5/8" tubes. The ram horns would be the 2-1/2" version. The application is strickly for the street, in a 3100 lbs car with regular gears and a T5 trans. The engine is a 350, nothing special, 10:1, iron heads with a cam and Holley 750 DP one a single plane manifold. I kind of like the advantages of the ram horns (flow quite well, quiet and long lasting) compared to headers. Since I wont be revving this engine to the moon probably 5500-6000 rpm max, would I really get that much more power with block hugger style headers? Any comments or advise would be greatly appreciated.
In my experience there isn't any signifcant power difference between rams horns and shorty headers. Both give up power to tuned full length headers, but that doesn't sound like an option for you. Besides you stated it's a street machine which I'm sure will spend more time at a 2000 RPM cruise in 5th than it will at red line at WOT. So the argument about 15-20 hp at 6000 RPM for long tubes is rather moot.

These will put your engine somewhere in the middle of best max power, not as bad as OEM under the sparkplug manifolds and not as good as long equal length headers. The SBC will show a 15-20 hp gain for a equal lengths over the OEM drop manifold, but against the rams horn or shorties its more like 10 at red-line and WOT. Often equal lengths will show considerable droops in power output when the engine RPM isn't in an area compatible with the resonant frequencies of the pipes. So on the street just puttin' around it doesn't matter a whole lot.

An aside, I think for how you intend to use this that your compression is too high, you're over carbed, and the manifold choice would be better with a dual plane. This drives questions about the cam timing, final gearing, piston and head selection? 10 to 1 is a lot of compression unless you've got a long winded cam, some choice combustion chambers, and the proper contour pistons in there.

I think the choice of a cast iron exhaust manifold provides greater stability and less maintenance than headers. What-ever the selection, I recommend stainless fasteners from the connection to the head thru every nut and bolt to the tail pipe. Their resistance to rusting makes maintenance a much more pleasant chore, especially where headers are concerned since you know going in that you'll have to tighten things up from time to time.

While on headers to the head fastening, let me recommend that you mock this up and select different types of fasteners for different locations such that you can actually get some form of a wrench on the fasteners after the engine is installed. Typically I choose between ARP stainless 12 points, studs with a nut, or Allen heads depending on what can be gotten at specific locations with a wrench of some sort after the engine is installed. While doing the mock-up correct any header or manifold mounting holes that don't align with the threaded holes in the head, this eliminates fastener alignment, installation, and cross threading problems. This will save you sooo much pain later on. Check the spark plug clearance while doing this, it's a lot simpler to dimple offending tubes now than after the engine's installed.

I always use aluminum or copper gaskets between the header and the head and between the the header flange and the head pipe. These will resist blowing out or burning up for quite a while if a fastener loosens and you can't get to it right away. I also use a flex joint somewhere along the transmission area in the head pipe to decouple the headers with engine movements from the rest of the exhaust system that sees chassis movements. This really reduces tube fractures and bolt loosening in the headers. These can be stainless over-braided joints if you've got big bucks, a doughnut and outside clamp joint, or simply a short length of flex pipe with stainless band style motorcycle muffler clamps. Use either a H or X pipe somewhere ahead of the mufflers. These provide an overpressure escape when you're whipping the throttle so when running dual exhaust any one side of the engine can see the flow provided by both mufflers and tail pipes. It also mellows the sound, helping to keep the noise police off your back, but still lets the world know there's a V8 under the hood.

Bogie
 
#17 ·
Since we're talking about fasteners a bit, do any of you guys wirelock your fasteners? I have spent many hours wirelocking on aircraft and it works great. Do the heat cycles make this not such a great option? The only downside is you have to redo it if they loosen, but they shouldnt move.
 
#18 ·
speede5 said:
Since we're talking about fasteners a bit, do any of you guys wirelock your fasteners? I have spent many hours wirelocking on aircraft and it works great. Do the heat cycles make this not such a great option? The only downside is you have to redo it if they loosen, but they shouldnt move.
OMG another airplane guy.

Yes it works well, after-all it's the heating and cooling cycles that push them backwards till they loosen. So if they can't turn, that stops 'em coming loose. NASCAR and other racing venues require header bolts be safety wired, ARP sells a NASCAR approved bolt already drilled for safety wire, see http://www.arp-bolts.com/catalog/Catalog.html

There's also a gadget out there that uses a cam shaped piece of metal that engages a custom headed bolt on one end and rests against the header tube at the other, all retained with an E-clip. These work well, but are pricey at around 50 bucks U.S.

For my street engines I just use the combo's I mentioned and tighten 'em up when-ever they need it. I guess mostly because street headers are often in tight places where just getting to the bolt head can be a real challenge. The long term lesson has been that a set of headers when put on the engine before it's installed can prove to be impossible to get at once the heater box, A/C compressor, power steering pump, steering shaft, and other interesting pieces get mounted. The variation in bolt types that allow you to get at them also makes it a lot easier to remove and replace the headers as the exhaust system needs work. I did a lot of that on my S10/15 conversions before it came to me to put a piece of flex in there to decouple the engine and chassis movements. My personal truck was pretty brutal in that regard since the body is fastened to the frame thru solid aluminum pucks instead of rubber and the engine/transmission is rubber mounted. So it went thru a period where it really pulled the Sandersons apart every few months.

Bogie
 
#20 ·
454C10 said:
The hp difference between manifolds and headers depends greatly on the engine setup. On stock engine, then there isn't that much difference in max power. However, big cams, more compression, bigger intakes, et, then the difference can be 80+hp.
80+ hp? Wow, that's seems like alot. BTW, my heads are 3986336's (1971 350 76 cc chambers according to Mortec), the cam specs are 288 degrees adv duration, .480" lift. Sorry, that is all I have for info on the cam. The intake is a Weiand team G.

Bogie, you are right about the mismatched parts (carb, intake, compression too high), but it's what I had left in the shed and decided to slap it all together anyways and hope for the best. Having said that, maybe I just answered my initial question! However, I'd still hate to give up hp by using exhaust manifolds.

I really like the ones posted by slate84, does anyone know who makes those?
 
#23 ·
Attachment Gadgets

Bogie -- The gadget you mention in your post is a "Stage 8" fastener. FWIW, I have used them on a couple of engines (I'm not a pro, just a hobbiest) and been absolutly satisfied. As you say, they are expensive, but if you need a longer screw for a particular location (A/C bracket, maybe) they'll happily exchange with you through the mail. Seems like a pretty-much user-friendly company. I think they are located in San Rafael, which is in Marin county, just a little north of the Golden Gate. BTW, Bogie, I always enjoy your posts. You bring a lot of wisdom and patience to this forum. Thank you for that.
 
#24 ·
PatM said:
Bogie ..... I think they are located in San Rafael, which is in Marin county, just a little north of the Golden Gate. BTW, Bogie, I always enjoy your posts. You bring a lot of wisdom and patience to this forum. Thank you for that.
Thanks for the kind words.

Marin county a little north of the Golden Gate. Ahhh, wine tasting, beautiful mountain to seashore vistas, redwoods, clean ocean air, next bed and breakfast better than the one you just passed. What a way to buy bolts!


Bogie
 
#25 ·
The trick to eliminating header gasket leakage is the tightening routine. I run huggers on my small block and have never had a leak after following this tightening procedure. After installing any headers the trick is to re tighten (check) them once a week for the first month. They will eventually snug up and should seal perfectly without further leakage. This has always worked in my experience with sbc's regardless of build. As the heat shrinks the gasket from a new installation, checking the bolt tightening weekly for the first month should prevent gasket burnout. Of course use quality materials at all times for best results! :)
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top