[super-dime]

I've got an 82 S-10 I've been building on for a few years now, and am currently experimenting with a 305. I've read some of the other threads and noted a lot of opinions from those, but one thing I didn't see was the combo I've been thinking about trying. Its bored .040 and I was thinking on going with a 327 crank for a shorter stroke. Now, with the b x b x s equation, I'm coming out with a 291... I've never heard of a 291 and can't find anything online... am I in the dark, or is this combo unthinkable? If its possible, what power could I get out of this? Open to any and all suggestions!

[techinspector1]

I can't think of even 1 good reason to build a 291 small bore motor.

[Hippie]

You won't find pistons for that combo without spending a ton of money and as much as I like weird combos that one sounds like a disappointment waiting to happen.

[my87Z]

i'm sorry but i have to agree, this sounds like a complete waste of time. the 305 already has a small bore which kills horsepower, and now you want to take it's stroke away killing all of it's torque.

[DoubleVision]

As said, don`t waste your time on odd ball bore and stroke engines trying to get the perfect combo. The past words of wisdom are true, you can`t beat cubic inches. This is what makes the 350 so popular, fair amount of cubes, dead reliable and best of all cheap. The combo you have in mind would be fine if you planned on building something for mileage, but, you have to ask yourself would the cost offset for the price of custom pistons would be worth it. If I were building a engine for mileage I`d build a roller cammed 305.

[super-dime]

So the 291, not a smart move. Thanks fellas. Any opinions on where I should go with this, (outside of the usual "boat anchor" or scrapyard suggestions). I like the idea of the roller 305, tho I've never converted any flat tappet to roller before. I wouldn't think it would be that difficult, but is there anything I should know before getting started?

[cobalt327]

Originally Posted by super-dime

So the 291, not a smart move. Thanks fellas. Any opinions on where I should go with this, (outside of the usual "boat anchor" or scrapyard suggestions). I like the idea of the roller 305, tho I've never converted any flat tappet to roller before. I wouldn't think it would be that difficult, but is there anything I should know before getting started?

It makes very little sense to use a retro roller cam and lifters in a 305.

If you were to want to do a 305 w/a roller, at least start out w/a OEM 305 engine w/the roller cam and lifters already in it (think 5.0L L30), but I have to say for the same money, you can get a L31 Vortec engine and have your roller cam PLUS the good Vortec cylinder heads PLUS a 4" bore 350 cid engine to build on.

[Blazin72]

Just a suggestion here. You could stroke it with a 400 crank and build a 334. That'll give you some extra cubes. But, again, There is really no good reason to do this either. You'd be money ahead building a 350 or 383 if you were going that route.

[Vince Black]

I have been toying with the idea of building a V-8 S-10 Blazer for a while, and I would pretty much agree with everyone else about staying away from a money pit. I realize there are plenty of people who have converted the S-10 to a V-8, which in itself is being different compared to stock, but if/when I do, I am just going stock 305/TH350. Plenty of power there for me, but that's just my opinion, I can't remember the last time I got above 100mph with anything. LOL

[my87Z]

sad thing is that many 305's didn't make anymore power than the V6 that was put into the S-10's in the mid 90's. so going a stock 305/th350 in my opinion would be a waste of time unless you where simply doing it for the sound of a V8.

to the OP, first let me say get a 350. now that i've got that out of the way here goes. right now i'm building a 305 roller block from my 3rd gen camaro (parts car) to get it back on the road. i have already bought a set of 416 305 HO heads off e-bay, and i am having them cleaned up with some port and bowl work done to as well as having larger valves put in, the block is at the machine shop, it had to be bored .040, i've got KB145040 -12cc pistons, the block has is beeing decked .005 so i should get about 9.3:1 compression. a friend of mine gave me a set of pink 5.7 rods
that he bought years ago but never used, for doing some side work for him. i plan on using a mild cam (208-216°ish at .050) with a performer RPM intake i have lying around and a edelbrock 1406 600cfm carb that i also have just lying around. once all is said and done i should have less than 1800.00 into and hopefully get around 280-300hp/ 330-350tq out of it.

[DoubleVision]

I was referring to a OEM roller 305, as I wouldn`t spend the bucks on converting a flat tappet, especially on a 305.

[techinspector1]

As alluded to by Doublevision and Cobalt, there was an L30 engine which was the smaller brother of the much sought after L31 motor. The L30 Vortec was the 305 version and was tagged the 5000, whereas the 350 Vortec was tagged as a 5700. It uses a one-piece rear seal and factory roller tappet cam the same as its bigger brother. Casting number on the heads is 12558059 with valve sizes of 1.84" and 1.50". Cylinder block casting number is 10243878.

Editor's note: the following is from wikipedia.....
The Vortec 5000 L30 is a V8 truck engine. Displacement is 5,013cc. Bore is 95 mm, stroke is 88.4 mm. The compression ratio is 9.1:1. It is a based on the Generation I small-block from Chevrolet. It was replaced by the 4.8 L 4800 LR4 for the 2003 full-size vans. In van configuration it produces 255 horsepower (190 kW) net flywheel at 4,600 rpm and 290 ft·lbf (393 N·m) net flywheel torque at 2,800 rpm. The engine uses a hydraulic roller cam and high flowing, fast burn style vortec heads. Differences include bore and stroke, intake valve size, and smaller combustion chambers. L30 applications:
Chevrolet Express/GMC Savana '96 -02????
General Motors C/K full-size trucks

Personally, I would see nothing wrong with resurrecting one of these motors for a mild street application where you were looking for a little better fuel mileage than you might get with the 5.7 motor. The same Vortec intake manifolds from Edelbrock and others should work and I might use a simple vacuum secondaries 600 carb along with 1 5/8" long tube headers through the mufflers. If I were going to cam it at all, I might use a roller cam with around 210 degrees @ 0.050" with the stock 9.1:1 static compression ratio.

Since I have located L31 long blocks here in Phoenix for 200 bucks or less, I would think you could do the same thing with L30's.

[JeffB]

Funny how things seem to have a pattern when it comes to the SBC's,if you had a 283 you would get a flood of guys telling you to keep it,if you have a 305 or 307 they will tell you to get a 350.15-20 years down the road after many of the 305's have been scrapped to the Chinese will they be the "new" 283? Kinda makes you wonder "Back in the Day" classes in drag racing were based on cubic inch to weight ratio as some stock car tracks adhere to today.With todays economy the way it is we see a lot of "newbies" on the board that love their rides as much or maybe even more than those with fat wallets so" build on a budget" is important to them,telling them to get things that are not affordable is not helping them out.We really need a section for "budget builds" here to get these future rodders on the right path.

[cobalt327]

Originally Posted by JeffB

Funny how things seem to have a pattern when it comes to the SBC's,if you had a 283 you would get a flood of guys telling you to keep it,if you have a 305 or 307 they will tell you to get a 350.

Funny how that's what YOU see, while what I see is everyone saying to build a 383, period. Same basic money as to build a 350 (which is often less than what's required to build a 305, 307 OR 283, BTW), while offering more "bang for the buck".

15-20 years down the road after many of the 305's have been scrapped to the Chinese will they be the "new" 283?

The 305 will ALWAYS be one of the least desirable SBC engines, along w/the forgettable 267.

we see a lot of "newbies" on the board that love their rides as much or maybe even more than those with fat wallets so" build on a budget" is important to them,telling them to get things that are not affordable is not helping them out.We really need a section for "budget builds" here to get these future rodders on the right path.

If a "budget build" is what's wanted- there's no better build than a 350 SBC.

You can start out spotted a 305 block and I (or anyone else) can spec the parts to out horsepower that 305 engine w/a 350 SBC- for equal money- w/o starting w/anything.

A 305 is fine, as long as you don't mind having your *** handed to you by every guy w/a decent 350. To build a 305-based engine that'll run w/a good 350-based engine will NOT be a "budget" build!

Of course, if a budget-minded DD w/300-320 HP is your goal in life, the 305 fits the bill.

[DoubleVision]

I don`t like 305`s for performance, simply put. However, you can make them into a good street engine with good mileage. Especially the roller cam versions. When I built my Vortec 350 I sure thought about doing a 305, and likely would have had I been able to find one in useable shape.
A 305 in a low end street form is great on mileage, really dependable and has decent power, hard to ask for anything better than that.
A friend of mine had a 1995 chevy 4x4 with a Vortec 305 and I loved the low end power it had. That truck was a pleasure to drive.
In the future I`ll likely do a roller 305 build just for a street car with good manners and mileage. I really want to see how high I can get economy wise. I made a Vortec 350 get 18 1/2 to 19 mpg with a TH350, I wonder what I can pull off with a Vortec 305 and a 700R4? As for 307`s I like them, and I`d use one if I could find one in good shape where I could reuse the factory pistons. I also like 327`s, and in most cases since I can`t find 307`s I take a Vortec 350 block and stick a 307 crank in to make a 327.