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1983 Anemic 305


Buzzard
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Hi Guys,

OK, I've got two, a 1970 which is my hot rod unit still under construction and a 1983 original time capsule survivor with just 22,500 original miles on it. We just returned from a 1776 mile trip to the Kelso Washington meet and subsequent Oregon visitations. My question is this: I'm having an awfully hard time with only 150 HP on tap and yet I don't want to ruin the originality nor take away from getting 24.8 mpg on the highway. I know I want my cake and eat it too but damn it's frustrating to have to plan your passing well in advance. I've always had lots of power in all my cars and was wondering if anyone else has modified this early computer 305 with decent results? I seem to recall Edelbrock used to make some computer upgrade to this LD3 (?) early computer unit.Also I'm not subject to emissions where we live so I could upgrade the exhaust to a real dual setup (eliminating the cat) without affecting the originality. Has anyone upgraded the rockers to rollers and did they fit under the stock valve covers? How about a carb upgrade to a double pumper? Any input and feedback will be appreciated and considered.

Thanks, Bill

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Roller rockers need the tall Chevy valve covers...I'm assuming your 305 might have the low covers. No big deal besides the change in covers but it would be visually different.

A true dual exhaust would help but it's no magic bullet. To really wake the engine up would likely take some cylinder head work (or replacing with performance heads), a cam change, intake manifold change, etc.

Since your car has the computer controlled carburetor I don't know how much can be done to wake it up. Having the distributor recurved might help. You're limited by your desire to keep the car original...at least in appearance. Performance cast iron heads and a performance intake can all be painted to look original to the car if you like.

I'm thinking there's only so much you can and keep it original. You may really mess with your fuel economy if you make wrong changes. You may want to find a speed and performance shop where they're really knowledgeable about GM engines and fuel management systems from that era.

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The problem is you are just coming out of the morass created by emissions standards on your engine and there is still a lot of legacy crap inside and controlling it. You don't need anything fancy, like a roller cam, but you should consider a package of a cam, manifold, HEI dissy and a carb. That's probably $1000 or so. Then you need to install it. If you can do it yourself then the costs are lower but you should still probably buy gaskets and do a valve job adding to your cost.

Realistically, you still will have a 305 that runs better BIIWM, I spend the money on a good crate engine and be done with it.

I'll post a plug. I don't know where you are but there is a forum member, PackardV8 (Jack Vines) that builds engines and has an excellent reputation. Get hold of him and discuss your needs. You should have a 4-speed OD trans and a high geared rear end so mileage should stay fairly good. This way you can go up in cubic inches 350/383/400 and still be in good shape.

The dual exhausts etc will help minimally but the real significant changes are inside and bigger. Roller rockers require a new cam about a $800 pkg alone.

My 83 acquired a 355 SBC roller engine with Aluminum heads etc. Very happy with it but unless you fall into the deal I did, it would be an expensive upgrade.

Bob

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FWIW, a completely new 350" doesn't cost that much more than fiddling with the heads and cam on the 305". A 245hp 350" long block, which would bolt in and look as stock as one wants, is only about $1500, plus core and shipping. A built 383" which will make those passes like a rocket, would only be about $3500.

Driven the same fashion, an appropriately tuned 350" would produce essentially the same fuel economy as a 305". (But where's the fun in that? When the horsepower is there, it's fun to use it occasionally/appropriately ;>)

My 83 acquired a 355 SBC roller engine with Aluminum heads etc. Very happy with it but unless you fall into the deal I did, it would be an expensive upgrade.

Without knowing the details of the build, it's difficult to give an exact quote, but a typical roller cam aluminum head 355" runs about $3,000.

jack vines

Edited by PackardV8
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RQB3263....just ditch the electronic q jet carb. and direct bolt on a std. q jet ...one wire hook up....follow the wires back and remove them all and the boxes there associated with..install a vacuum advance HEI dist about 75$ delivered...Crane and many others make a series of "torque" cams/lifter kits about $350 and new valve springs (optional)....roller rockers would be a waste on this engine so forget that....Cloyes double roller timing chain $25 at CarQuest set is a absolute must....remove the EGR valve and install block off plate....remove exhaust thermostatic valve just below right exhaust manifold remove the flapper and weld up the cross shaft hole...remove the tubes from each ex port...(they extend about 3 inches up into the ex port)....and everything else associated with the P C system (pump, pully, brackets, belts, etc)...remove cat converter...check mufflers for restriction (hit them w your fist and see if they rattle)....install 160 degree thermostat w holes drilled to allow air to pass eliminate air bubbles...I did all these things and a few more (you may not need a valve job) but new head gaskets and good re torque might save pulling the heads later...I just (in May and June) did 3300 mile trip to South Bend and lotsa interesting points (including Myer's Studebaker in Duncan Falls, Ohio...highly recommended)...and got 21MPG on my 305 cruiser for the entire flawless trip...So there is a good weekends work ....RQB3263...BILL

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Good to see you here, Bill! Now that Kelso is in the rear view, it looks like Summer is making a comeback....

If I could have any engine in mine, I'd go for an LS1 or even an LM7 like I have in my Silverado. They are just so smooth and powerful and easy to live with!

If you insist on looking original, then the 400 you have could be made to look just like your 305, right?

On a budget, I'd think one of the later 80's motors that GM put in their trucks with the throttle body injection could be made to look like a carbureted motor pretty easily? I'm sure that could be built to make some power.

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I've been following this and I keep thinking, "why so worried about keeping it stock if you don't enjoy driving it that way?" If you change it in any meaningful way it'll never fool any judge who knows the stock criteria, and if you're concerned about the general public-who cares? The minute they see a GM engine in the bay, most folks are confused anyway. We have an annual classic car show every Saturday of Labor Day weekend, and the last few years there's been over 1000 cars. I'll drool when I see a cherry Nash Business Coupe or whatever and can't wait to peek under the hood. The minute I see a 350 crate motor in it, I'm bummed and start looking at other details. I wonder how many other folks do the same when they see the correct engine in a non-Stude year Avanti, because they think it's an aftermarket upgrade? Personally, I'd put the bucks into building up a nice replacement mill that'll give you the performance you want and save the original motor in proper storage, fogged and ready for selling the car to "the next guy".

Edited by GlennW
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Thanks for the support, Warren & Glen. I guess I knew all along what I was going to have to do with the 400 cid, It's just difficult when the car has such low miles. I don't really pound enough miles that even a slight sacrifice in economy would make much difference. I'll keep you posted but it looks like I've got a project for later this winter.

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  • 2 months later...

RQB3263....IM GITTIN IN KINDA LATE HERE BUT...JOHN MEYER, DUNCAN FALLS OHIO (MEYERS STUDEBAKER) ENLIGHTENED ME ON THE 400CID INSTALLATIONS...IT SEAMS THAT BECAUSE THE 400 IS A TORQUERER ENGINE THAN THE 305 THEY SOMETIMES HAVE CRACKED THE FRAME AT THE ENGINE MOUNT SUPPORT POINTS.....REPAIRING WITH THE ENGINE IN THE CAR IS ALMOST IMPOSSIBLE...JOHN CAN SUPPLY YOU WITH A DRILLED ENGINE MOUNT REINFORCEMENT PLATE TO INSTALL WITH THE ENGINE OUT....ITS A WELD IN DEAL I BELIEVE....REALLY SOUNDS LIKE A GOOD IDEA TO ME....MYERS ADVERTISES IN THE AOAI MAG AND ARE GREAT FOLKS....BILL RQB3263

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RQB3263....IM GITTIN IN KINDA LATE HERE BUT...JOHN MEYER, DUNCAN FALLS OHIO (MEYERS STUDEBAKER) ENLIGHTENED ME ON THE 400CID INSTALLATIONS...IT SEAMS THAT BECAUSE THE 400 IS A TORQUERER ENGINE THAN THE 305 THEY SOMETIMES HAVE CRACKED THE FRAME AT THE ENGINE MOUNT SUPPORT POINTS.....REPAIRING WITH THE ENGINE IN THE CAR IS ALMOST IMPOSSIBLE...JOHN CAN SUPPLY YOU WITH A DRILLED ENGINE MOUNT REINFORCEMENT PLATE TO INSTALL WITH THE ENGINE OUT....ITS A WELD IN DEAL I BELIEVE....REALLY SOUNDS LIKE A GOOD IDEA TO ME....MYERS ADVERTISES IN THE AOAI MAG AND ARE GREAT FOLKS....BILL RQB3263

Bill is correct about the difficulty in repairing the frame with the engine in the car but the problem with the frame can happen with a 350 also. My 74 400 SBC was replace with a 350 by Nate Altman shortly after the OP made the purchase. The frame still cracked. It is caused buy the factory that quit putting washers on the bolts that hold the motor mounts to the frame which then point loaded the frame with bad consequences. The 400 will exacerbate the problem but everybody should be checking their installations at some point.

This is some of the damage. I repaired it with a complete reweld of the cracks and a plate underneath spanning the cracked area. I don't need the 383 recracking the frame.

My repair - http://forum.studebakerdriversclub.com/showthread.php?70636-Let-Me-Recommend-You-Check-Your-Avanti-Engine-Frame-Mounting-Area

100_0860_zps9c64a03b.jpg

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Buzzard,

My 76 has the original 400 SBC in it. I chose to have the motor rebuilt and warmed up 4 years ago after getting the car. The motor was bored .30 over, making it somewhere around a 406. New pistons, hydraulic roller cam and lifter, Edelbrock intake, Performer carb, MSD distributor, block hugger headers, line boring and heads decked and headwork were all done to the motor. The shop that did the work builds a lot of drag racing motors, so the 400 was pretty light weight compared to some of the 500 and 600+ cube engines. The motor originally was rated at 175 HP. The shop did a good amount of head work, cleaning up the intake and exhaust passages. The motor was dynoed before going back in the car, turning out 365 HP and 460 pounds torque.

The THM 400 trans was replaced with a rebuilt 200R4 in front of the 3:31 twin traction Dana 44. Mileage went from around 14 to a range of 17 - 27 depending on how much fun I'm having on the road. Cost-wise, it probably would have been cheaper to go with a 350 crate motor, but I wanted to keep it "original". As the car doesn't have any of the smog equipment or catalytic convertor(cat was long gone before I bought the car), purists would not still consider it original.

I had the car built for the purpose of driving it and going to Studebaker, Avanti and antique car meets. The car has over 28000 miles on it since being rebuilt over 4 years ago. Components such as the brakes, gas tank and fuel lines, and suspension have all rebuilt, replaced or treated. I wanted a reliable car that would keep up (or ahead) of traffic, getting me there and back with a reasonable amount of certainty. The car has done that, but with a few hiccups along the way. I've driven the car to 4 International meets, 3 zone meets, both coasts and have had a lot of fun doing it. Good luck with your car and deciding how you want to do it!

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  • 4 weeks later...

Thanks for all the suggestions. A pal of mine has an experienced engine shop and has built many 400 cid motors achieving around 420 hp/ 430 lbs torque. Since I have a brand new short block it looks like a no brainer to go this route.

I'll proceed this spring and keep you posted as to the outcome. My trans is most likely a 200r4 so sourcing a bullet proof unit shouldn't be very difficult. Proper dual exhaust from Silvertone, cat delete etc should make it similar to plwindishes' '76. I have a serious SpeedPro Roller cam kit to top things off.

Cheers, Bill

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Thanks for all the suggestions. A pal of mine has an experienced engine shop and has built many 400 cid motors achieving around 420 hp/ 430 lbs torque. Since I have a brand new short block it looks like a no brainer to go this route.

I'll proceed this spring and keep you posted as to the outcome. My trans is most likely a 200r4 so sourcing a bullet proof unit shouldn't be very difficult. Proper dual exhaust from Silvertone, cat delete etc should make it similar to plwindishes' '76. I have a serious SpeedPro Roller cam kit to top things off.

Cheers, Bill

Good choice, Before I picked a cam I'd call a couple of cam mfgs and talk to their techs. Tell them what you will be building, the use you expect to pit it to, and car data like weight-rear ratio-etc. They will make some recommendations based on that and you can compare the recommendations and narrow down the cam. I like the roller choice, eliminates startup and oil issues during it life. Bob

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you might want to check with the exhaust police, (state or federal) before you ding the cat or cats on an '83. i'm a state licensed repair shop and inspection station in vermont and i couldn't legally inspect your post '74 vehicle without a catalyst system intact. to paraphrase mr. vines, your results may vary.

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