dear all camaro fans.
with respect i have a 1977 camaro base with inline 250 cid engine.
im planing to tune the engine,many people told me to put a v8 under the hood but im going to try it on inline 6.
my 1st plan is to put long headers and make the exhaust dual.
then im going to change the camshaft and carb with chevrolet 305 carb.
finally im going to improve the ignition system.
im looking forward to recive some technical advice.
has some one did this job ?

 

Welcome to the forum!
Haven't done a 6 cyl. build, but I've seen a few running around locally. I did own a old 1965 Dodge Dart years ago with a well built slant 6 engine. I ran a Holley 600 on it, headers, and a pretty radical cam. It would beat most small blocks, and only a few well built V8's were faster. Ran the 1//4 mile in low 13 sec. range. It was lots of fun.
I think a built 6 cyl. would be lots of fun and if it was fast enough it would surprise a lot of people. It only has a couple drawbacks. The cost will be very high compared to a V8 swap, and there will always be those who just don't like the looks of a inline 6 cyl.

 

i6 has a ton of torque, not much hp though. also the fuel economy is much better. same reason dodge is dominating the diesel market with their i6 vs ford and chevy's v8. i think seeing a i6 2nd gen would be cool, ive yet to see one. everyone does a v8 swap, nothing wrong with being different

 

LOL my bro swapped his 250 for a 292 from a pickup. It had a Saginaw 3 speed manual too. It wasn't a monster, but we saw every bit of that 130 MPH speedo. I think you can still get the Offy four barrel intake. That with a header and cam, I would see whats out there for the head. I would think that you could get a larger intake valve.

 

I'd sure have to disagree about the fuel economy being much better! Most inline 6's don't get much better fuel economy than a small stock V8, and when you begin to build them even a small amount they'll quickly drop to worse. Fuel economy of any I6 or V6 is dependent on vehicle weight, and a 6 has to work a little harder to pull the same weight, vs. a V8, so mileage is usually sacrificed. On a good day my old Dart got 15 stock, and after a build that gave it around 325hp I couldn't get much better than 9 mpg. A 350 with 325 hp would have done much better.

 

I have built 2 I6 engines. One Ford 200 for my 66 Mustang and the other was a 250 for my 65 Chevy truck. The one for the Truck I did a similar build. I used a mile R/V style cam not too bumpy but better than stock, dual exhaust headers and a offenhauser 4bbl manifold with a 600 CFM Edelbrock. The engine I had was one with a non integral head so changing the manifold and header was easy. Not sure about what head your engine came with but if you are planning on a 4bbl then you may want to try to fine an older truck head. As for the ignition system I used a distributor from an HEI engine. To a 65 Truck that is a HUGE! improvment.

Massey

 

hi.
thanks for replys.
1st im going to put 3'' headers with two colectors and dual exhaust.
with headers approx. how much h.p i will gain?
for carb at the moment i have rochester single barrel carb for performance shal i put 2 bbl or 4bbl with how much cfm for 500 rpm ?
can anybody help me with performance camshaft?
many thanks for helping me with my project.

 

There are not alot of performance goodies out there for that engine. For the cam swap I did I didnt really see a HUGE HP gain but I did feel a good torque gain, it could have been my grind since I was going for a good truck engine. The best advise I can give is talk to Comp Cams (the guys that I got my cam from) and tell them what you want and they can recomend a good cam for you. I went with an Edelbrock 1405 Carb which is a 600CFM manual choke carb. It worked well with my cam but could flood the engine really easy. My pistons were stock style 8.5:1 comp at .030 over. It was not a super build but the engine sure woke up after I did that. I didnt do any work to my head other than lap the valves and have it checked over really good. I dont remember the brand of headers I used the exhaust shop I took the truck to found them and installed them for me. If I remember right he found them for a 63 Nova. I did this engine back in 93-94 so I dont know how many of the parts I used are still going to be available.

Massey

 

I would go with either the small 450 cfm 4 barrel, or the Holley 2300 2 barrel that's either 350 or 500 cfm. Going any larger will just flood the engine as Massey said. Which cfm you choose depends on the camshaft. And chosing a camshaft depends on whether you keep the stock head, or have it ported. Not much to choose from on I6 heads, so you'll have to spring for reworking your's.
Comp Cams has a nice variety of grinds available for the 250 I6, so I'd check their site, or call them and see what they reccommend for your application. I don't know enough to spec a certain lift or duration for a Chevy 6.

 

hi.
im realy confused and i need some help.
if i want to tune my inline 250 the cost will be the same if i put a v8 350 cid under the hood.
also its not so easy to find tuning parts for inline 6 but for 350 i can find everything.
i realy what to do???
if you were in my position what would you do ?
please help me to make a good choice.
regards.