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Are headers on a 3.8l v-6 engine worth it?

Vincent Pasquarell
11-19-2003, 12:57 PM
I own a 1986 Olds Cutlass with a 2 bbl carburetor that I bought about a year ago, It now has 47,000 miles. When I bought the car it lacked power, but I attributed that to the spark plugs and air filter never being changed, which was partially true. I have replaced the spark plug wires the spark plugs and the air filter which have given me more power. I also checked the timing and took the car to a transmission guy who made some adjustments to the linkage ( it was shifting to 3rd gear too early).
I replaced the catalytic converter with an aftermarket converter (30% better flow), and put an open element air filter on the carb air filter base. I got rid of the air cleaner assembly/ heat riser.

My problem is that I'm not quite satisfied with the power. it seems that on cold days the car has more power than on warm days, also the tranny jerks somwhat sometimes (the transmission shop says there arent any problems).

It was suggested to put a v-8 in the car but I dont have the money or the time to do that. I asked my mechanic if it would be worth it to put headers dual exahust and headers on the car & he a said it would just make the car loud. I,m not looking for super v-8 power, just more power than what I have. It was also suggested by a friend that putting headers on may adversely affect the air/fuel mixture going through the carberator and hence engine performance.

Does anyone have any comments on this ? Would headers on this engine be worth it ? I already have the converters, I would need the headers, tailpipes and 2 mufflers plus possible some welding & misc parts (probably $500-$700). Has anyone put headers on a gm 3.8 l v-6 engine ? What were the results ? Any comments would be appreciated.

thanks in advance,


The Burning Rom
11-21-2003, 09:04 AM
Headers make a BIG difference on the series II 3.8L motors....I don't know about the old series I motor that you have though.

03-31-2004, 10:21 AM
I've been wondering about headers too. I'm in the same boat as you. I have a 1987 Cutlass Supreme with the 3.8 v6 2bbl carb. I have totally bypassed all the pollution/smog pump components and I noticed this gives me more HP , but I'd like a bit more. I had a single inlet/dual outlet flowmaster (made specifically for v6 f body camaros and firebirds) installed in place of the factory muffler, but notice no increase in power at all. I was wondering if cutting off my cat converter and installing headers would make a difference. I found headers made by hooker headers for 156$ from summit racing. Still too scared to invest in them unless I hear stories from people who have bought them .

06-02-2004, 07:51 AM
I have an '81 Cutlass Supreme "hand me down." 3.8 liter 2 bbl 6 cylinder. Specs say its rated at 110 hp at about 5,000 rpm. That sucks in a car this size. I have some ideas: Swap intake manifold with larger Olds 6 cyl engine and put in a 4 bbl along with installation of headers. I don't know if anyone has had any success with improved horsepower by installing headers. Bypassing smog control equipment is a little beyond me.....could use a little guidance.

06-03-2004, 01:58 AM
Basically by "bypassing the smog pump" I mean that I removed it all. I removed the smog pump and all the lines connected to it. Theres a line running down to the catalytic converter, I removed that one and plugged up the hole in the converter with a bolt. The other line connects to the rear of the intake manifold behind the carb. It's actually on the back of the manifold, facing the firewall. I removed the line from there and plugged the hole with a threaded plug fitting. A few more things that will boost HP a bit (not much, but every little bit helps) is upgrading your ignition system. I changed out my dist cap and rotor with a high performance set from Accel . Also put on some Bosch high perf 8mm triple silicone spark plug wires. And Bosch Platinum +2 spark plugs. Accel also makes a high performance ignition coil for this engine which I might get soon. Also, be sure to change your fuel filter (on the front of the carb) if you haven't already done so. Another thing I notice makes a BIG difference is the gasoline. I have been running 93 octane gas in my car. I notice that it runs much better, plus I actually get better mileage. I even did the math to prove it. Try filling up your car all the way full, then write down your mileage on the odometer. Then when you drive the car till it gets to "E" go fill it up all the way to full again. Then look on the gas pump to see how many gallons of gas your car just took. Then go write down the mileage again. Subtract the mileage from your mileage you wrote down before, and thats how many miles you drove on the number of gallons your car just took. So divide the number of gallons into the number of miles, and thats your gas mileage. Say for instance, you drove 212 miles. And your car just took 15 gallons to fill it up. Then your mpg would be 14.3 miles per gallon (212 divided by 15)Lately, I've been getting about 16 to 18 mpg on the highway (during road trips) and about 12 to 14 mpg for everyday driving. This is also with the AC on full blast at ALL times, so I can probably get even better mileage if it was colder outdoors.

06-03-2004, 02:12 AM
Another option to consider: Edelbrock makes an intake makifold and a camshaft to fit this engine. Don't know how much horsepower it would produce though. I've see them in summit racing equipment's catalog, or go look at http://www.summitracing.com
I bet this setup along with a 4bbl and headers would produce a nice extra bit of horsepower. But the 20 thousand dollar question, exactly how much Hp??

06-03-2004, 12:24 PM
Hey thanks for all the input.

OK, to sum it up, the cheapest way to get a little hp boost: silicone plug wires, bosche plugs, high perfrormance distributor, high-end air filter, maybe an aftermarket catalytic converter for better flow, bypass the smog equipment.

The headers are tempting but the cost and effort may not be worth it. I like your idea of a high performance coil. I think my idea of putting in a manifold and 4 bbl may also end up too costly and time consuming not to mention the possibility of ruining an already fair running engine.

By looking at some of the posts in here, I have seen that putting in a new oxygen sensor may help with performance, but is this part of the smog equipment? In addition, I heard that a "crankshaft position sensor" may also be worth replacing. I have already fixed all vacuum hoses, tuned up engine, installed PCV, new fuel filter (all the basics).

I will try the 93 octane gas and let you know how that turns out. I will also do periodic replies under this post to give updates. I have to believe there are thousands out there with the lack of horsepower issue in these older cars!

06-04-2004, 12:16 PM
Oh I forgot to say so, but I did change my oxygen sensor also. I did it all at the same time when I changed the cap and rotor, wires and plugs. So I can't tell you for sure how much it actually contributed to my horsepower gain. Also, this engine does not have a "crankshaft position sensor", but they do have a "throttle position sensor" on the carb. Not sure exactly what this will do though. I also pour a bottle of fuel system cleaner in my gas tank like every 6 to 8 months. It reduces carbon buildup in the engine. If there is any black smoke at all when you start your engine, then you have carbon in your engine. I couldn't even see it until I was standing behind my car and I used my remote start. It wasn't a lot, but it did puff out a bit a black smoke right at startup. Another thing that I wanna do is chop off my catalytic converter. (Yeah I know its illegal, but who cares) My brother used to have an 82 cutlass 4door with a 3.8 v6 and he cut the converter off and had just a muffler on it. The damn exhaust sounded like a v8! It had a bit of a throaty tone to it. It also had a good bit of horsepower. He was always screeching the tires with no problem. I wonder if the converter being gone had to do with it. But on the other hand, his engine had been rebuilt by the previous owner less than a year before he bought it.

11-06-2015, 09:48 PM
i dont understand there are so many bsers out there every 3.8 litre ive ever looked at come from the factory with headers and considering how many millions and millions of these engines out there if you dont have headers already you could probably get some for free good luck theses engines are awesome i would almost catagorize these engine with the old slant sixes ive seen so many that will still smoke the tires after 400k plus kms and never had a valve cover removed for any reason LOVE em im going to do mine ill post my experiences and gains thanx

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