I6 intake, carb, header upgrades? Worth it?

[Custom/Ten]

Just watched the video from the link. So cool! That's more hp than the 350s had.

[slomotion]

Originally Posted by CST10

So you noticed a difference with just some bolt on'so. Yours is a 292 vs 250. I wonder if it's worth it. I guess I could always start collecting parts and just do the bolt on'so and the. Cam swap later if I still wanted more..............

Granted, the 250 and 292 are different engines, but the principles are the same in both I6's. Another way to look at it is the cam won't give you that much advantage unless you allow it to work, and it can't do that well without the external components.

[CST10]

Originally Posted by slomotion

Granted, the 250 and 292 are different engines, but the principles are the same in both I6's. Another way to look at it is the cam won't give you that much advantage unless you allow it to work, and it can't do that well without the external components.

You are correct there. Also most cam profiles move the power band up the rpm range as the cam becomes more aggressive. I guess for normal lower rpm increases an RV/marine cam may be best.

Decisions decisions.

[GRX]

Yep. Hence post #11. Power band from idle to 3,500 rpm.

[CST10]

Originally Posted by GRX

The stock 250 cam is not performance oriented by any means. Around 390 lift intake & exhaust if memory serves. A common upgrade I often did for customers was install a Mercruiser marine cam which can be used with the stock springs. A step up is the Crowler #03240 cam which is what I am running in my '69 250. Similar to the "towing cam" of old. My '69 c10 is running stock intake & Monojet carb, with split headers. Nice improvement in low end with very smooth idle. Highly recommended you go with the #84008 lifter/spring/retainer kit along with it.

Cam: http://www.crower.com/camshafts/chev...ulic-cam.html#

Question? How's that stock manifold working with those headers? By that I mean, when the engine is running the stock intake used the stock exhaust manifold to provide heat to vaporize the fuel better for a better air/fuel mixture. I heard, not experienced, that they tend to run very rich without it when the engine is cold. Any truth?

[CST10]

Originally Posted by GRX

Yep. Hence post #11. Power band from idle to 3,500 rpm.

This maybe the best choice for my setup as I don't plan to run the drag track. Just a nice Cruiser is all I'm looking to for......... along with standing out in the vast sea of V8's everywhere.

[Custom/Ten]

Originally Posted by CST10

Question? How's that stock manifold working with those headers? By that I mean, when the engine is running the stock intake used the stock exhaust manifold to provide heat to vaporize the fuel better for a better air/fuel mixture. I heard, not experienced, that they tend to run very rich without it when the engine is cold. Any truth?

Eventually someone with some experience might speak up, I'm just talking from research here. This is langdons stovebolts solution to adding headers, common sense says this will take longer to heat the intake than a heat riser but after reading up on it this is what I will be using when I build my 250. Along with langdons cast iron headers. That said, plans can change real quick lol, but at the moment I'm really diggin these two items of his.. I suggest you take a look at it. I hear nothing but good things about it but go check it out for yourself, at least you'll see some cool stuff on there.

[Shaky]

I built one performance 250. It made good power. It was expensive.

Ultimately, I think you bump into two big considerations when hopping up the six: 1) the head really needs the bolt bosses milled out and 2) Fuel distribution with a single carb is less than optimal.

Overcoming those requires a more serious investment.

I keep my sixes stock now and hot rod V-8s if I want power.

[slomotion]

Originally Posted by Custom/Ten

Eventually someone with some experience might speak up,......................

I'm not sure I understand what this means. Several posts have sounded pretty detailed to me.

I have the water heated intake manifold on my engine, but bypassed it after I didn't notice any real gains with it. I don't jump in my truck and go, I usually let it get a little temperature before I take off. I have a 195 deg thermostat and the cast headers seem to warm the aluminum intake pretty quickly. I've never had a carb icing problem with this set up like I did with a crate 350.
From what I've heard and have no reason to doubt it is, the single quickest gain in power and reliability is the HEI.
My truck isn't quick, it's heavy and was designed as a work truck, I just wanted something a half-step out of the mainstream, but what it has got going for it is reliability, smooth operating, and easy to work on. It'll exceed the posted speed limit.......(I guess my age is showing now....)
Probably a good investment for the money spent is a copy of "Chevrolet Inline Six-Cylinder" by Leo Santucci. This is an excellent resource on I6 speed/power modifications.

[CST10]

Does anyone know if the Langdon headers or clifford headers have any issues if you have a clutch and the Z bar?

That sure is a good looking 292 engine there.

I'm buy that book and read up some before I dive straight in.

I'm looking for reliability more than anything. The stock set up is very reliable as it is. Just want a few of the cool wow factor items to be different. If I can gain more power, that's a bonus too.

[Custom/Ten]

Quote:
Originally Posted by Custom/Ten
Eventually someone with some experience might speak up,......................
I meant in response to the last question he asked. The one that no one had answered yet. The one about loosing the heat riser when you add headers. Ya know , the question you just answered. wasn't saying the previous posts weren't useful. When I said person with experience I meant someone other than myself as what I was posting was based on research, NOT experience. Wouldn't want to upset anyone lol. Hope that clears that up for ya. I just got excited when someone said they wanted to build a 250 cause I think they're really cool and unique. Thought I would share some of my research since I liked the topic. Most people just rip them out because it's easier and cheaper. Anyway I'll just shut up now lol. Good luck with your 250 sir.

[slomotion]

Originally Posted by CST10

Does anyone know if the Langdon headers or clifford headers have any issues if you have a clutch and the Z bar?

That sure is a good looking 292 engine there.

Thank you.
If you look closely at the photo you can see where Langdon designed the headers to run either side of the Z bar.

Custom/Ten, No worries, I misread what you meant.

[RichardJ]

Installing tube headers and loosing the heat valve on a six is little different than tube headers on a V8. The setup on the six may continue to provide some heat after warm up, but like slomotion, it has never been an issue on my engine.
In the winter, I can push the manual choke off, after a couple of blocks. In the summer, I'll pull the choke out just enough to set the idle up till I get out of the driveway. It never gets cold enough in SoCal to require much choke on any engine.

I ran water to a block bolted under the intake like slomotion mentioned and had the same results. No change with or without water. The newer Clifford manifolds have a built in water passage that runs the length of the manifold. I don't know if heating the manifold helps them or not.

[Shaky]

I had the Clifford shorty two-piece headers. I made my own Y-pipe to bring it to a single exhaust. The Z-bar fit.

I also had the Clifford 4-barrel intake with the coolant plate below. I was driving it in the winter so I never tried it without it. I never had a problem when using it.

[CST10]

Really great info. Thanks everyone.

Where does everyone get these nice side plate and valve covers from. They are nice looking with the fins.

[Scottcoda]

Originally Posted by CST10

Really great info. Thanks everyone.

Where does everyone get these nice side plate and valve covers from. They are nice looking with the fins.

I got mine from Tom Langdon.. Great quality and awesome great guy to talk to.. It may take sometime to get the covers depending on what he is working on but he will tell you up front if it might be a while.. Mine were well worth the wait.. Very happy with them

Tom's website http://www.12bolt.com

['68OrangeSunshine]

Originally Posted by CST10

Does anyone know if the Langdon headers or clifford headers have any issues if you have a clutch and the Z bar?

I have Clifford long tube headers. The Z-Bar fits and works fine.

[CST10]

Originally Posted by '68OrangeSunshine

I have Clifford long tube headers. The Z-Bar fits and works fine.

Sweet. Thanks for the photos and info. I actually have a spare 250 engine on the floor in my shop that I am planning on building up then installing in the place of my current 68 c10's 250 engine.

I really appreciate all the insight and help everyone.

[GRX]

Originally Posted by CST10

Question? How's that stock manifold working with those headers? By that I mean, when the engine is running the stock intake used the stock exhaust manifold to provide heat to vaporize the fuel better for a better air/fuel mixture. I heard, not experienced, that they tend to run very rich without it when the engine is cold. Any truth?

Sorry for delayed response. Just getting back from vacation. As others said above, it is not as big an issue with these engines. Though with the headers I do have to work the choke more in cold weather before the engine is at full temp. Which is fine by me since I have to tweak the air/fuel mixture screw on the Monojet carb with big temp changes as well. Would rather do that than rely on modern sensors. Old school all the way for me. Yep. Points too

[CST10]

Yea. I'm looking at adding some headers basis the advice given and the minimal issues. Thanks guys.

['68OrangeSunshine]

Originally Posted by Scottcoda

I got mine from Tom Langdon.. Great quality and awesome great guy to talk to.. It may take sometime to get the covers depending on what he is working on but he will tell you up front if it might be a while.. Mine were well worth the wait.. Very happy with them

Tom's website http://www.12bolt.com

Scott- I think that's not Tom Langdon. Tom Langdon is www.stoveboltengineco.com

Might it be Tom Lowe?

[slomotion]

For what it's worth.....
Since back in the old days when we were building/driving flathead engines up to our current vintage engines, we had a procedure for putting headers on. Whether it was a help or not I don't know, but I have never had a gasket burn through as long as the flanges were true and flat.
Make sure everything is clean - head, studs/bolts, header flange, and gasket. Get a can of good quality aluminum based hi-temp rattle-can paint. When everything is ready, paint both sides of the gasket and let it dry. Then paint it a second time and install everything when the second coat is tacky, taking the nuts/bolts up to torque specs. After the engine has been run up to operating temps and cooled down again, re-torque.
I don't know if it's helpful, but I do know it doesn't hurt, and best of all, if you have to open the engine up again, the gasket won't rip in two needing a bunch of scraping to remove all of it.

[Scottcoda]

Originally Posted by '68OrangeSunshine

Scott- I think that's not Tom Langdon. Tom Langdon is www.stoveboltengineco.com

Might it be Tom Lowe?

Yes you are correct.. I meant Tom Lowe, Thanks for correction!!!

[CST10]

Originally Posted by slomotion

For what it's worth.....
Since back in the old days when we were building/driving flathead engines up to our current vintage engines, we had a procedure for putting headers on. Whether it was a help or not I don't know, but I have never had a gasket burn through as long as the flanges were true and flat.
Make sure everything is clean - head, studs/bolts, header flange, and gasket. Get a can of good quality aluminum based hi-temp rattle-can paint. When everything is ready, paint both sides of the gasket and let it dry. Then paint it a second time and install everything when the second coat is tacky, taking the nuts/bolts up to torque specs. After the engine has been run up to operating temps and cooled down again, re-torque.
I don't know if it's helpful, but I do know it doesn't hurt, and best of all, if you have to open the engine up again, the gasket won't rip in two needing a bunch of scraping to remove all of it.

Really good info. Thanks I had never heard of this procedure before today.