I6 Speed part questions

[Primered_69]

IS there any difference between the offenhauser manifolds and the clifford performances manifolds? Is one that noticibly better than the other one.

[fastwillie 696969]

offenhauser been around along time i would go with offy

[shifty]

I don't think it's going to matter either way from a performance perspective. The inline 6 sucks for fuel delivery anyways because of the where the carb sits in relation to the three delivery points. Other things like the split port for cylinders is horrible for good flow.

I would skip the new intake or even new exhaust and cut right to trying to set yourself up with an EFI system. Just my 2¢.

There was a big article in HotRod magazine last month about building up L6's. Shows a lot of thing from Kirby's Sissell or whatever and a couple other places included info.

[FUNMUDDER]

I'd go with the clifford. It will cost more, but give you more power. I got that Hot Rod issue, and a 292 bored .060 with a clifford intake, holley 600, a comp cam, and headers made 255 hp and 315 lb ft. Now that is pretty good for an old six banger

[shifty]

Pretty good, but when you realize that they spent $2k+ on that carb'd 6-banger and think about how you can have a V8 or even late model engine that gets the same gas mileage with better performance and reliability (maybe 10-20 less in torque) for the same cost, seems kinda silly to me to keep the 6 and spend money on it unless you're all about keeping the original engine in the truck.

I looked into the EFI thing and started calling around - the lump port mod and EFI on the heads alone (like from the article) was thousands of dollars and required special exhaust and intake.

Then again - I could be a bit jaded. I just wasted $700 building up the L6 I've got in my truck only to replace it with another engine and another $100 on a 4spd tranny + torque converter out of a ¾ ton panel truck that I'll never use also.

:\

[boraxman]

I have a nice new Clifford cam if your interested PM me.

[70 shorty]

While I can't give you any comparison btwn Clifford and Offy, I will give a thumbs up for the Clifford intake on my 250. My 6 will surprise a lot of V8 owners.

[TP from Cntl PA]

Originally Posted by shifty

Pretty good, but when you realize that they spent $2k+ on that carb'd 6-banger and think about how you can have a V8 or even late model engine that gets the same gas mileage with better performance and reliability (maybe 10-20 less in torque) for the same cost, seems kinda silly to me to keep the 6 and spend money on it unless you're all about keeping the original engine in the truck.

I honestly don't see how you guys can say a Inline is less reliable than a V-type engine of ANY make. Their is a reason why the OTR trucks, Farm Tractors, and industrial equipment run inliners.........

Some of the best engines we ever had in our work trucks were inliners, whether GM's 250 or 292, or Fords 300...........Low Mantainance, and kept pulling when everything else would have given up.

[shifty]

Originally Posted by TP from Cntl PA

Some of the best engines we ever had in our work trucks were inliners, whether GM's 250 or 292, or Fords 300...........Low Mantainance, and kept pulling when everything else would have given up.

You will get no argmument from me there, sir. I agree with you 100%.

I actually think we agree more than you know, but I get the impression that your idea of "reliability" is different than mine.

Originally Posted by TP from Cntl PA

I honestly don't see how you guys can say a Inline is less reliable than a V-type engine of ANY make.

If your idea is reliability is that reliability == longevity, then, yes, L6 is a superior engine. The L6 is outdated in technology and it costs a fortune to really bring it up to date and, when you consider dollar per horsepower, it's just not worth it.

Now, I won't sit and argue this one out - I KNOW in terms of LONGEVITY when it comes to mechanics, my L6 will OUTLAST a modern V8 with EFI (like my vortec) any day. There's no comparison. There's an ass-ton of things to break in new engines, but like .. nothing to break in an L6. So, yeah, in that regard, outside of vibrations, trying to kill an L6 is like one of us trying to beat an elephant to death with your bare hands.

If you ask my opinion, in terms of reliability...the 4.8L Vortec in my '03 Sierra started up every time I turned the key for as long as I owned it (put an assload of highway miles on it and traded it in). With my L6 (both of them), if I didn't manually choke, tap the gas pedal twice, then turn it over and tap the gas again a few times, it wouldn't run on its own long enough to warm up, even after having a pro go through and carb and timing (when I had HEI on and when I had points on) with new plugs, wires and everything else under the sun.

I also don't hafta wait for a late model V8 to warm up, which is another big plus. On the topic of heat, my new V8 (and even the smallblock 350 that was in my '70 Impala) never had problems firing when the engine was hot like my truck sometimes will.

I love my L6, but it's a love-hate relationship. It's all torque and less HP. With any model of V8 I've owned, I've never had the little quirks and hassles (call it "character") that my L6 has. My L6 doesn't strike me as a "reliable" engine. It strikes me as a "mule". It gets up and goes when you want it to, it will really kick some ass and lug a load when you need it, but if you rub it the wrong way, it either won't move an inch or it'll kick you in the face.

[TP from Cntl PA]

Originally Posted by shifty

If you ask my opinion, in terms of reliability...the 4.8L Vortec in my '03 Sierra started up every time I turned the key for as long as I owned it (put an assload of highway miles on it and traded it in). With my L6 (both of them), if I didn't manually choke, tap the gas pedal twice, then turn it over and tap the gas again a few times, it wouldn't run on its own long enough to warm up, even after having a pro go through and carb and timing (when I had HEI on and when I had points on) with new plugs, wires and everything else under the sun.

We had a '69 C-10 with a bad body and box but the chassis and the 250 6 was still in great working condition............Used it for a farm truck for years. It was started and run 365 days a year twice a day at the very least(Once in the morning and once at night) to make the trip from the house to the farm in everything from below zero to near 100, in the sun, rain, wind, snow, and it never let me down............Not to mention we pulled stuff with that truck that most people would be afraid to even touch with a new 1 ton dually. My friend that farmed with me and my brother bought an F-250SD with a Powerjoke..........Guess which truck lost a turbo during planting in the spring when you absolutely NEED to have a pickup in working order, in the mean time the Little 1/2 ton with the anticient 250 6 pulled the load of two trucks.

My main complaint is everytime I see someone wanting to keep a 250 or a 292, it always seems that the "Put a V-8 in it" is brought up............Like the Straight 6's are some POS, poorly designed powerplant..........Well, that really rubs me the wrong way. Those little Inliners made me more money over the years than any other engine...............And I think it is great people want to KEEP one of these instead of throwing in a V-8 like everyone and their brother is anymore.

Not trying to ruffle any feathers, but when a man asks a question he wants answers, not two cents about whether it is worth it or not..........

[shifty]

Originally Posted by TP from Cntl PA

My friend that farmed with me and my brother bought an F-250SD with a Powerjoke..........Guess which truck lost a turbo during planting in the spring

The FERD. Shoulda bought a CHEBBY. FERD SUCKS and that's why.

Originally Posted by TP from Cntl PA

My main complaint is everytime I see someone wanting to keep a 250 or a 292, it always seems that the "Put a V-8 in it" is brought up.

Don't tell me about it - I get it all the time when people see my inline 6. And I'm still rebuilding the original 250 L6 for my truck, too.

Originally Posted by TP from Cntl PA

...........Like the Straight 6's are some POS, poorly designed powerplant.........

See my reasoning above -- costs 5x as much to build them up and you can't get them over 400hp without spending ten thousand bucks.

Originally Posted by TP from Cntl PA

And I think it is great people want to KEEP one of these instead of throwing in a V-8 like everyone and their brother is anymore.

Like I said, I'm keeping mine. But I don't haul anything, so I'm going for a Gen III V8 because it's more practical for my use.

Originally Posted by TP from Cntl PA

Not trying to ruffle any feathers, but when a man asks a question he wants answers, not two cents about whether it is worth it or not..........

I agree and add this: They also don't want someone coming in to start an argument, effectively hijacking their thread. Which is the lesser of two evils?
I actually answered his question...did you? Then you felt the need to give your 2¢ and continue with it instead of answering his question.

Did I lie in my post when I said "it won't matter b/c fuel delivery sucks?" No. It's a known fact that distribution to the 1-2 and 5-6 cylinders is poor with stock or aftermarket manifold.

fitment will be roughly the same with both manifolds. Performance is going to be roughly the same also. As for the arguing on whether they're worth it or what money they've made, that's outside the scope of the thread, has nothing to do with the original poster's question, so if you want to argue about it, I'm not going to get the thread closed by commenting back any more Nothing personal.

Which would I choose personally? The Clifford. Adn I'd drop a 600cfm+ carb on top of it. And it would see a siginificant gain in power. But it's still an inline 6.

[Lgriffin]

To answer the original question. Offenhausers are usually considered better for the bottom end performance, because they have shorter runners, Cliffords are better on top end. That said "I don't think it's going to matter either way from a performance perspective", depending on how you intend to build the 292.
1963 292 420 4.11 Detroit locker Camper
1968 327 485 3.73 Daily Driver

[Dick Dale]

Offy is better,try www.inliners.org for more help.

['68OrangeSunshine]

Originally Posted by Lgriffin

To answer the original question. Offenhausers are usually considered better for the bottom end performance, because they have shorter runners, Cliffords are better on top end. That said "I don't think it's going to matter either way from a performance perspective", depending on how you intend to build the 292.
1963 292 420 4.11 Detroit locker Camper
1968 327 485 3.73 Daily Driver

That's what I've always heard: that the Offy intake was good for low end torque and the Clifford was better for high RPM applications. The Clifford intake is plumbed for water jacket cooling from the heater hose. The Offy was designed to replicate the GM cast iron intake and bolt up to stock exhaust.
I use an Offy intake and Clifford headers with an Edelbrock 500 CFM AFB-clone 4 Bbl carb on my 292. The first 2 components ran 25 years on my last engine. Sadly, the 390 CFM Holley didn't make it to the next lifetime, so I had to get a new carb.

[shifty]

Originally Posted by '68OrangeSunshine

That's what I've always heard: that the Offy intake was good for low end torque and the Clifford was better for high RPM applications. The Clifford intake is plumbed for water jacket cooling from the heater hose. The Offy was designed to replicate the GM cast iron intake and bolt up to stock exhaust.

I've always heard the same. Having the water passing through the intake on the Clifford will help heat up the carb leading to faster warmups. I would go Clifford; the motor already has enough torque and, I could be smoking grass, but I'd rather have something that doesn't need to bolt up to stock exhaust, has porting for water, nets more in higher RPM's than something else that will really give a kick in the ass in the torque dept.

I've got a stock intake right now on my truck with Dynomax headers (dual exhaust). I haven't plumbed the exuast yet and I'm not planning on it. The collectors on the headers hang way too low - literally, here's a picture:





I can't handle it. I can't lower my truck like that. I had to beat the living bejesus out of the #1 tube just to get the damned thing to fit around the manifold.

[shifty]

PS if anyone wants to buy a brand new pair of Dynomax headers (pictured) for an L6, I'll sell them for $100 and I pay shipping. They sound great, but I plan on laying frame in the truck eventually, so the headers gotta go.

I paid $160 for them brand new. They come with adapters and all hardware. I modified (with ball peen hammer) on the #1 pipe to make them fit under a stock exhaust. Should not affect performance. Need to be sandblasted and repainted, I will throw in a half a can of Eastwood's Header Paint with all application brushes for free.

['68OrangeSunshine]

With a 292 the headers are about level with the frame. Have you considered shortening the header down tubes? If that's possible.

[70 shorty]

I just have the Clifford intake, with no water jacket plumbed. I can reach in standing outside the truck first thing in the morning and hit the key and it will start instantly every time. I currently have no choke on the carb, but will get it working again for the winter, but when the choke was working in the winter I just hit the gas pedal once or twice, and again, instantly fired up, no cranking whatsoever. I have a 390 Holley on mine.

[69chevytruck]

So would a two single barrel carb intake or three carb intake supply more fuel to the front and rear cylinders?

[shifty]

Originally Posted by '68OrangeSunshine

With a 292 the headers are about level with the frame. Have you considered shortening the header down tubes? If that's possible.

Thought about it. When I think about investing the effort and plumbing the exhaust, I think about how much more I would enjoy dropping the LS1 into the truck and plumbing that instead, so that's next on the agenda.

[shifty]

Originally Posted by 69chevytruck

So would a two single barrel carb intake or three carb intake supply more fuel to the front and rear cylinders?

I think the problem lie in the structure of the intake, not the carb on top.

[CraigS]

A redesigned 3 carb intake would supply an even amount of fuel to each of the cylinder pairs. The current manifold is uneven because the runners are of uneven length. Less drag on the intake charge to get to cyls 3 and 4 vs the other ends.
A side note- if you want 400hp without spending ten thou(not saying you did), add a turbo. Should be able to get 400hp easy. Don't know how long the motor will last.
I am putting a GM turbo (3.8L) on a Ford 250 inline.

[pjmoreland]

I bought a set of headers from Clifford about 13 years ago that had the collectors up in the engine compartment so there were no clearance issues. Of course I think I paid way more than $160 for them.

[Drobny]

Does OFFY have a website?
Pat

[shifty]

Since nobody else has answered, I dug in last month's HotRod magazine and pulled up the following set of links you will find utterly useful in finding performance parts for your inline 6:

Offenhauser (This sales site is worthless 'cept for finding dealers):
http://www.romax.addr.com/offy/

A huge Offenhauser parts distributor (I cannot endorse their service!):
http://www.offyparts.com

Clifford:
http://www.cliffordperformance.com

Sissells Automative (they do massive reconstructions of parts for your engine):
http://www.sissellsautomotive.com

Injection Logic (if you want to convert to EFI):
http://www.inkectionlogic.com

Crower Cams & Equipment:
http://www.crower.com

Crane Cams:
http://www.cranecams.com


These should keep you busy. Check out Sissell's site and download their price sheet. Check out all the cool head designs and other crap they got for inlines. Lots of cool stuff. You'll find lots of intake options at clifford and possibly at offyparts.com. You'll be amazed at what you'll find at JC Whitney also ...