Inliners International Forums General Discussion Engines Is there any reason not to use a stock cam?

For a 250 that will be a daily driver in a Delta 88, would there be any reason to use a cam grind other than stock? My primary goal is economy and reliability.



Dan

You can if you want but I would consider something like a Comp Cams 240. Part#61-113-4. Works with all stock springs ect.
At least get a set of new SBC springs put on the head. Only cost about $35 or so. If you really want to run a stock cam use the one for either an Intergrated head or the stock Mercruiser Marine cam. What gear ratio is in the car? What transmission are you planning on using? Jay 6155

Gear ratio is likely 2.73 or 2.41. The transmission is a turbo 350 with stock converter.

If you do not have the th350 yet - try and find a early 80's one. The TH350C have a lock up converter and will help save a bit of fuel.

One issue may run into is at cruise the airspeed in the intake might be really low which can cause drive ability/fuel metering issue.

Might be better off finding a dual jet off of a 231 V6 from around 1980/83. The Venturi's are smaller and will give better metering.

All the jets/primary needles are the same as the Qjet so parts are around to adjust the fuel curve if needed.

On these you set WOT mixture using the jet and pri needle tip diameter, then set part throttle mixture with the mid and top step of the needles.

With those bad tall rear gears. A 700R4 would be better than a TH350, also a 200R4 would be another good choice for mileage & better get up & go for a daily driver.


MBHD

NOTHING WRONG WITH A STOCK CAM FOR YOUR APP, GOOD LOW END TORQUE PLUS YOU WONT HAVE A CHINA MADE CAM IN YOUR ENGINE

I do have a dual jet, it's on the engine I'm pulling out of the vehicle. The car currently has a pontiac 301 and that has plenty of power for me but it has a rod knock. If the 250 can come close to the same power, I'll be happy.

I'd have to adapt a dualjet onto the 1bbl intake manifold...would the dualjet be that much better than the current 1bbl?

Would the comp cam 240 give me any better mileage over stock?

Overdrive is a possibility someday, but not yet. I have to focus on getting the engine built and installed...this needs to be my primary vehicle very soon. My current vehicle is about to bite the bullet.

I drive about 50 miles per day round trip. Primarily highway miles.


Dan

I have gotten better mileage w/a small RV type camshaft, Offy intake & a 4 bbl carb over the stock 1 bbl carb.

Buy an Edelbrock intake manifold & a 1 -2 bbl carb. Think Larry can post a pic on here, he might even sell you his?

Or use a small volume manifold like this http://www.ebay.com/itm/5416-Offenhausse...c4cfc40&vxp=mtr

Don't let anyone trick you into using a BIG Clifford intake to get better mileage, it is not intended to give you better mileage.

MBHD

Does your trans have a dual bolt pattern? If not than you will have to get a different one. If you have to change transmissions the th350c (lockup) is a direct bolt in as is the 200/200c. The advantage of the 200 is it's 2.74 first gear. The 350 is 2.52 and the "c" means lockup converter for gas mileage. Can you find out exactly what the gear ratio is? We changed a friends Delta 88 (nice cars buy the way) from a 2.41 to a 3.08. What a difference! Maybe there is a car in the salvage yard that could donate a lot of parts. One car to look for would be a Chevy powered 77 Delta 88. It will have a Chevy trans (either a 350 or 200) that you need and a 2.56 axle ratio.(please verify axle ratio). As to the Duaejet, this is the carb that I am going to try first on my build. The calibration for the 301 should be close enough to start with for the 250. Why not try both carbs and see which one does the best? You could start out with the 1bbl on the stock intake and then install the 2bbl on another intake and see what happens to power, mileage ect. You could have an adapter made for the 1bbl intake but for the price of a custom made plate a little more will get you a intake. PM me if you decide to get rid of the carb,air cleaner ect from the 301 I might want to buy them. Jay 6155

My trans is the BOP style. I'm getting an adapter plate for the transmission so I can use it with my chevy bolt pattern. Since this is strictly a passenger car application I'm not worried about going with the adapter. I can get the adapter for around 40 bucks. I do want to get the overdrive or lockup transmission at some point, but right now it's not a good time.

I have a '79 pickup that I am also doing an engine for, along with rebuilding the front suspension.

On top of that I'm saving up to buy a used hoist. Once I have my own hoist, doing the tranny will be a piece of cake.

I have a bad back and I'm so tired of going up and down under my vehicles. How many here have tried to weld exhaust while the car is on jack stands? I bet quite a few have...it sucks.

So right now my priority is to get this motor built, and make it reliable and economical. I want to put it in and then worry about only maintenance things for a while.

<begin rant>

I'm so sick of working on front wheel drive late model cars.

I have a 1997 Buick Skylark with a Quad4 engine and the car is junk. It has so many little electrical problems it's just crazy. I replaced a ball joint in it last summer and the control arm was so thin that I ended up needing to replace the whole arm.

My wife has a 1995 Olds 88 and last year the front subframe literally started to fall out, and the steering shaft disconnected from the rack and pinion leaving us stranded. So I get it towed to a buddies house and he's like "seen this a bunch of times, the subframe mounts are rotted out and we'll have to weld new pieces in. Oh and by the way, this thing is rusty as hell and it won't last much longer even after the repair."

I have a 1979 C30 that starts every day. Rides very rough, but it is dependable. I can rebuild the entire vehicle. I had to renew my license plate recently and it cost me $43 bucks. Parts are cheap for it.

So I don't want to drive a C30 everyday, but I want vehicles that are repairable like that. I had a car payment once and I'd rather spend that money on something I can repair (until I get too old at least).

</end rant>

:-)

Or a cheaper small volume intake like a stock 194 intake-cheaper by far!

Measure the lift on your stock cam, ALL lobes. If they differ, the cam lobes are worn (not necessarily visibly worn), and then there is no point in using THAT cam. I have a rule, if a stock cam EVER needs to come out, there is no point in putting it back in, ever. As others have already mentioned, you can get a more modern grind that can offer better mileage. You'd need to get a set of new lifters to match and break the cam in properly. Costs maybe $200 and no other changes are needed with a very mild "optimized" cam.

just to stir the pot, If this "OPTIMIZED" camshaft could produce an increase of one mpg, from 16 mpg to 17 mpg, with gasoline at $3.50/gallon. It would take about 15.5K miles to recoup the $200 dollars. A 10% increase in gas milage would make it go from 16 mpg to 17.6 mpg which would then cause the break even point to be at the 10.1K marker. In the second instance, you would have to travel 20.2K miles before you could say "I've saved $200 dollars" because you spent the $200 to switch cams, you then "broke" even at the 10.1K marker and at the 20.2K marker, you have then actually $200 more bucks in your pocket. Sometimes saving money, costs money, how much can you afford to save?

Stock cams are not good for anything, other than to make the engine run.

Get a camshaft you would be happy with. Who cares how much the cam costs, if you are happy with it, that is all that matters.

MBHD

Adding performance oriented parts for the sake of economy is almost like a double edged sword, on the one hand, you can increase engine efficiency and mileage with parts tailored for better performance, but on the other hand you tend to drive the vehicle more aggresively because of the power increase and defeat the purpose of doing it to begin with.