I'm ready to buy my rotating assembly for my ProCharged engine build.

I'm looking at Crower crankshafts, their "Enduro" SBC series specifically and I'm unsure which stroke to buy. Also they need to know the following:

Note: Specify Rod & Main sizes.
Note: Specify rod length to insure proper piston to counterweight clearance.

Strokes:
3.480"
3.500"
3.625"
3.750"
3.875"
4.000"
4.125"

I do know I don't want to bore my original block.

Can anyone help me out with what the largest stroke that will work is and what the answers are to their 2 questions above?

Also what length rods can I consider?

5.700"
6.000"
5.850"
6.125"
5.700"
6.000"
6.250"
5.850"
6.125"
6.200"

and what is "B.E. Bore"? lol, damn I'm such a newb!

I would really appreciate it. I've never bought internal bottom end parts before.

Thanks!

 

You're looking at a set of custom pistons to take much boost. That being the case, it's cheaper to dump the 305 block and get a 350 block. If you insist on keeping the 305 block, order a 3.750" stroke and 6" rods to go with your custom pistons. Trying to go any farther on stroke could lead to the rods hitting the bottoms of the bores. At 3.766" bore you'll have 334 cubic inches.
If you step up to a 350, then you can safely use a 4" stroke with a 6" rod. At 4.030" bore you'll get 408 cubic inches.

 

Thanks!

Yeah I'm sticking with my 305 for sure, even having custom heads done. I've been told the JE APBA 305 pistons would be great.

 

Can I ask why you're sticking with a 305? I havent seen a tech bother in a while to look at the casting number to see if the engine was a 305 or 350 so thats not all that bad to deal with. If its to 'be different' its been done.

FYI I was running 16PSI on a completely stock 91 LB9 for quite some time, and the previous owner of that engine was doing the same. It has about 80k+ miles of being abused and its fine. Still has good compression and holds pressure well. It was also quite fast. I'd be disappointed if you dumped that much time, money, and effort into a 305 block and were not running well into the 11's with it.

 

Because I don't care about max power, it's the original engine, it will be different, I like a challenge, I think I can pull it off well, and I think it will make plenty of power for me anyway.

A few reasons that are more personal than just wanting to be faster.

 

DUDE!!! .. I have a 305 on my bird... I rebuilt it and now I regret rebuilding it... I initially thought this will be enough for me yada yada.... but well "NOT"... at first yeah sure it was enough... then it was like dude WTH did I do... now I am building a plan for my 383 stroker project... I put into my 305 more than 3K in parts alone, well 1/5 was labor... machine shop I believe...

you will think that the 305 will be enough for now, but later on you will be regretting not going with a 350... going with a 350 4 bolt block will give you many more options... well to each their own... it's your money and it's your desire and will to built up a 305...

 

If your worried about it being original then keep the old block on a stand in the basement wrapped in a plastic bag then get a 350.

If your planning on running any sort of stroked crank you will need to clearance the block for the added stroke. I did mine and took about 2 hours using carbide cutters and die grinder.

If you don't care about max power then why bother blowing money on a supercharger for no real gain. Wish I had money like that to waste...

You can go and tell people its a 305 and they wouldn't know the difference unless they ran the casting number on the back of the block, against the firewall, buried under wires...

 

You don't think going with a 5.7" rod to have a meater piston is advisable?

Also, with a 305 bore, you want either 3.48" or 3.75" stroke so you can use off the shelf pistons, rods, and crank. Any other stroke is gonna require either custom rods or pistons.

 

Yeah I think I'll just do a 5.700" rod and 3.480" stroke. Maybe a 3.75" stoke if it won't require any more machine work.

 

Meatier doesn't mean stronger, it just means heavier. Plus a worse r/s ratio.

 

If you go 3.75" stroke and 5.7" rods, the only shelf pistons are hypereutectics with a 10cc dish from Keith Black. These are fine for mild boost, but you sure don't need a forged crank if you choose these, these will fail long before any cast steel crank, even the $190 versions from Eagle and Scat.

 

Well I'm looking at this from Crower as a complete and balanced rotating assembly. The crank and rods are specifically for boost applications and the APBA verson pistons are as well. I'm really not sure on the rings yet, I don't know if gap-less is needed for 24psi.

Crankshaft: E95121X4
Connecting Rods: ML93000B6-8
Pistons: JE APBA Pistons: 174002
Rod Bearings: 85301
Main Bearings: 85401
Rings: Total Seal brand plasma-moly (Gap-less)
Pins: Premium H-11 tool steel
System Balanced: YES

 

If that's to your liking, and you can afford it, then do it. It's good quality stuff.

 

Thanks. I'm absolutely determined to get the best complete balanced assembly from Crower that I could afford and the parts I chose are high boost specific. I am trying to over build so there is minimal chance of any kind of failure.

 

In that case, you're screwed, because there are no good 305 blocks from World or Dart. :-)

 

He's boosting it, there is a tremendous difference there. The 305 is my sig runs mid elevens with an essentially stock engine (port work, larger injectors, tune and alky injection). I would agree that if he were running naturally aspirated he should simply toss the 305 in favor for a much larger bore, but the boost factor doesn't know, nor does it really care which engine it is huffing into, only that it is being fed the right amount of fuel....

92GTA, you don't even need to stroke it for what you are after. The 305 stroke is fine, in fact, it shares a very similar bore and stroke with the 2JZ engine, so why would you want to hinder it's RPM potential. Your running a smaller bore than a Grand National V6 engine, while at the same time, your running a much larger intake valve than a Grand National V6 engine. Stepping up to a 1.94" intake valve is every turbo buick guys wet dream, so you will do just fine with the stock 3.76" bore, and 3.48" stroke. Just pay close attention to compression, port velocity and cam specs....

 

Cool!

Yeah those Crower P/Ns are stock rod length and stroke. JandJsSpeedShop is doing my AFRs and NewEraRaceCraft is already working on my cam grind, they are however waiting on the flowbench numbers on the heads before grinding.

What do you guys think about 8.5:1 CR for the F1? Wrong thread I know lol. I was going to let NERC help me with that one anyway since they are the ProCharger experts.

 

But since he's buying a forged crank anyway, with 4340 rods and light forged pistons, there's no real disadvantage to adding the stroke. With a big, barely streetable solid roller cam, it'll still pull well past 7000 rpm, even with the stroke. The boost will compensate for the added demand that comes with the stroke.
There is a little more friction, but it's spread over a longer area, so wear is less affected.
Boosted combos like taller gearing, and with that, the extra stroke will drive better when not at full boost. Mileage could even be a tiny hair better.
And if the cam is huge, then the extra stroke will help with emissions.

 

It all depends on how much air you're going to get into that engine with your supercharger. The stock 91 engine I have is... 9.3:1? I have not sat down and figured out what the DCR is but it was handling 16psi fine on 91 octane. If this is just for fun and not max power (I would not call 24psi anything other than going for max power and I doubt you will see that much anyway), I think 8.5 is going to be way low. And 7000RPM is probably not a good idea, might be too much for the supercharger to handle. I have not looked at any of the specs on the Procharger but IMO there is no point building the engine for high RPM with one.

I still think you're dumping too much time and effort into a 305. Unless there is something wrong with it, I'd run it like it is if you're not trying to make a ton of power. Its going to make a lot anyway. If you build it up and its the original numbers matching engine (as if that matters), what are you going to do if that engine lets go and trashes the block?

Anyway, do as you wish. The 3.75 crank you'll have to clearance the block just like a 383 build. I would run the longest rod you can reasonably use and have JE make some pistons for you. If you want to do all that. Forget the gapless rings, those are just going to get you into trouble. Contact the piston manufacturer, follow THEIR recommendations. Exactly.

 

Whoa, I never said 7K lol. I'd guess 6,200 maybe, 6,400-6,500 TOPS. I planned on running a nice small pulley and that 24psi I only expect under *perfect* conditions right before a shift anyway. For my actualy CR, I was goign to follow the advice of the shop that's doing my cam and getting my blower from since they specialize in that.

I'll see what JE says about the rings, I admit I was just totally guessing.

 

Like a stock 305, then.

At the very least, it will require clearancing the oil pan rail (could be argued either way whether or not that is "machine work"). May also require a small base circle cam, depending upon the rods.

I have to admit I cringe every time I see a subject line like this. It's usually "to be different" or "to keep the original engine", neither of which are worth a bucket of spit. It would also be different to walk around in leg irons, and would have a comparable effect.

 

Well to be fair, given that it's going to be forced induction, the displacement of the engine is not so important.

I ponder building a 5.0 or smaller, but mostly because I want to build a handling car and not a drag racer. A smaller displacement engine won't make enough torque to rip apart my T-5 transmission or my 10 bolt rear.

 

I realize that, someone else did and its not something I would suggest with a belt driven centrifugal.

I'm just thinking you may want to rethink some things. 24psi is a lot, and unlikely. I dont know if someone actually sat down and figured out where it would fall but I cant see that happening. I may have been able to wring 20psi out of my Vortech but that was on a stock engine. With much better heads, a proper cam, a good flowing intake, the psi is going to drop. You'll make a lot more power than I would have, but thats just how it ends up. psi is all relative, to what you are trying to force air into. If you were to really stuff 24psi into it, track down Preston Smith's old video when his car was still Vortech supercharged. Thats what it should do then. I'm not sure you're looking to build a low 10's high 9's car, but then again maybe I'm wrong. The only time I took my car to the track was not long after I put the Vortech on and with nothing other than that and SLP 1 5/8's headers, a 'catback' of sorts, and a shift kit (as if that did anything) it ran a 13.8@104 with a 2.3x 60' time at 7-8psi max. From 7psi to the 16psi I started running after some tuning and deciding what the heck (its a stock motor after all), I have no doubts it would have ran mid to low 12's with traction. It was that much faster. I did some gtech (I know I know) runs with it and it ran very very well. How fast do you want to go?

 

It takes more pressure to make the same power with a smaller engine, so yes, it is important because you need to build to a higher level.

 

Have you given much thought to heads, exhaust, and intake for this turbo setup?...i hope your not expecting to run it all on stock components that would be such a waste.

 

Is that time all on a stock bottom end? and stock 305 heads?

Sorry for 2 different posts I just noticed your times...

 

Sorry, dont mean to be the update police, (second 305 thread I dug up today) but, is there any progress?

As for you 350 guys shaking your heads at me sayin "what is he good for?" "They should ban his @$$!" I have something thats worth a reply. For every 350 guy on this board, there are just as many (maybe more?) 5 liter guys wanting some quality info... so please, be "tolerant" thanks.

 

I recall being there, having a 305, thinking I should be able to get it to the same HP as a 350, at slightly higher rpm, missing 45 ft-lbs, but able to make up for it with more axle ratio, since it'd rev a little higher.
And EVERY 305 owner will feel the same way until they do build the 305, then swap it all onto a 350. honestly, doing the 350 swap is all the quality info a 305 owner truly needs, since 350 blocks are still more common in the salvage yards, and are still under $150 for a long-block assembly, that, thanks to TBI instead of carburetion, doesn't even need over-bored.
It's far cheaper than stroking a 305, and with far better results, due to un-shrouding the valves, and the reduced high rpm friction from the ribngs, despite the extra diameter. Because the friction increase from the rings increases exponentially with rpm, and that just isn't the way with bore, which is a linear increase. The exponent is small for the extra -.27" stroke, but it still comes out worse.

 

Update? You can check the history board, but the car is history.

Friends dont let friends build 305's. Not when 350's and LS engines are readily available.

 

Oh, LOL
LOL... I NEVER thought a 305 will make the same power as a 350..LOL If anything, my tolerance for the engine has gone up... No replacement for displacement, and NOT all 305 owners regret building it, just the majority of the ones without a power adder...
GM's Joe Bertsch and Denny Davis (who was part of Zora Duntov's hi po group from the 60's) designed the 305 in 1973 to be a more efficient (hence the ideal bore to stroke ratio) on unleaded gasoline (leaded gas was being phased out). It was NOT designed to get the most HP, but neither was the 350! IIRC the 350 was made to be a more economical engine option for the Camaro, which, did the quarter in 16.1, 0-60 in 7.8. and that was with a 290hp rating! A lot of this info is available in GM's history book..
also...
The 350 was actually supposed to have MORE bore than 4.0". They were concerned with rings wearing flat spots in them, so they gave it the "off" number stroke because 350 ci was the demand from engineering group vice president Ed Cole.
ALL OF THIS HISTORY is accurate and trust me, I am not some "guy" who is new at engines, cars, repair work, whats been tried and most importantly racing. I am a certified auto tech, here in Austin, TX and have been for the past 9 years and also help out on some serious racing (sdba). I understand the 350 will make more power, but please understand I am looking for a quick 305 powered (probably 310 by the time its done) to resemble the best of what the original GM engineers were looking for. Better power, better parts, better ECU, better power, better mileage and thus a better 1985 Camaro Z28. I seriously doubt a 305 has more friction than a 350 at ANY RPM, smaller rods, less load, and yes, the bore size DOES count... thats just common sense that anything with more surface area gas a bigger contact patch thus more friction. FWIW, I have a vortec 350, sitting in the garage, waiting, I am still interested in 305 stuff for the fun of it. I AM going to build one for the fun of it... also, I could care less about a 350 when an LSX is out there. I see an LQ9 in my future......

 

I don't know what the 305 haters problem is. Maybe their mothers didn't hug them enough as baby's or something but I would take a 305 over that bitch *** 4 banger they tried (in a 3,000+ lb car)any day maybe a 350 does make more power for the money but not all of us are cake eating money bags that can just plop money out of our *** for all that stuff well you say save up your money then get the 350 I say some of us can't wait 10 years to have a nice ride us poor folk have to do with what were dealt with I know the guy said he had the money to do what he wanted so tell him what parts he needs to accomplish his goals and leave it at that who knows how much longer we all will have to play around with these cars before the government starts manditory car crushings and we are all required to drive electric pieces of crap like Al Gore wants us all to do so let the man alone and let him build his 305 any way he likes savy

 

Nate's gonna be my 305 powered attack dog from now on... get 'em NATE! I can't wait til the modded LQ9 goes in, so when someone says "go 350" I can say, why would you even bother with that? LSx will make more power... see what they say then... oughta be a whole new set of excuses to hear.. let me guess... 1) TPI 2)PRICE 3)ORIGINALITY FACTOR.. wow! this sounds SO familiar!! Sounds exactly like the SAME crap I said about the 305!! They get it now! Im sure everyone gets the point??? Thanks Nate! And to anyone else who doesnt care what engine I want to run...what ever the reason!

 

So tell me one good reason to put a 305 back in once you pull it out. 350's are dime a dozen, and amazingly enough there are enough suckers out there that you can actually sell a used 305 longblock and wipe out any cost you may have incurred buying that 350. Cost isnt an issue unless you're trying to make life difficult on yourself.

 

My answer is you don't live where I do. I have checked junk yards and ebay and all that and no one will take less than 300 dollars for a 350 ci motor running or not. I purchased my roller 305 from my mechanic neighbor for fifty bucks plus some other parts he chipped in just to clean out his shop I was then able to invest that 300 plus into the rebuild. I am pleased with what I believe will be a good engine for the only thing you can do around here and that is cruise about in it. when I got the camaro it didn't have an engine at all so the 305 was a perfect fit for what I was working with. Also Oregon has stupidily adopted many california emissions laws here if a cars registration is transfered from a non emissions area (rural) to the Portland metro area wich includes hillsboro then that car must pass smog their in also any engine swaps performed on a vehicle must not be of a displacement other than factory installed or optioned for that model and year. for example my car was built with the 2.8 v6 but had the option of of the 305 so that is the only two motors I can legally put in my car. Before you say how will they know it's not a 305,because if you transfer the registration from place to place then they are required to check they engine block i.d if it's not what it's supposed be you can be fined or prosecuted. some of you out there continue to lambast the 305 but all most people want is an answer to what parts to buy for a peticular engine. If you can't just give him a straight reply then leave it alone. If he wants your opinion then he'll ask for it. To each his own for now we still live in a free country where we can do things like tune on cars who are you to tell some one they shouldn't rebuild the engine of their choice. Sorry for being so long winded but stuff like that really pisses me off.
IT'S CALLED FREEDOM OF SPEECH IF YOU DON'T LIKE IT SUCK IT!!!!!!!!

 

You arent looking very hard then, I've found them everywhere I've been for less than that. As far as smog, they've been sticking probes in cars where I live longer than anywhere else in the nation and I havent seen anyone check a casting number on a block since 1991 and that guy was just looking for trouble.

Read your last line again. I will advise against someone dumping a bunch of money into a 305, every single time and people getting mad about it will never change my mind.

 

You may want to call your local ref (smog regional office) and ask them about your engine swaps.... on an Fbody you can legally drop in an engine that was in any newer Fbody, as long as it is an upgrade... for instance in my 87 4BBL Bird I can legally drop in a 350 or an LS1 as long as it's fuel injected... in addition if I were to do that I would have to install all emission related equipment, on the LS1 that would include fuel tank and transmission...

Now I decided to rebuild my 305 because of a tight budget and some fear that it wouldn't pass emissions... well to make it a simpler story... the money that I spent on parts aside from the internals, not including the camshaft they are all interchangeable with a 350... but I would have had to come up with the other stuff that goes with the 350 FI... not just the block... so yeah in my case it was a budget issue... my future plans are a 400RWHP 383 stroker... yeah I won't get the full potential of the 383 with an emissions legal fuel/air delivery system, but I'll be satisfied with the added umph of 150+ HP over the current approximation output of "my" 305

 

There's no doubt the 305 is a waste, bigger cubes will make more power. Considering the price of the 350 roller engine, used, the fact it will bolt right in, everywhere and only needs a couple things ALSO found in the same yard (eprom and 22lb. inj.)... I agree, and I would not tell anyone to mod the 305 unless they just wanted to. I WANT to try it... a lot of people do this... just part of the hobby... No biggie.
Nate, I wouldnt go off on a tangent over this, yeah it pisses me off too sometimes (because its my car and thats that) and people should help out with ANY build if they can but they are honestly trying to save you a buck. Thats all. 305 or 350, have fun dude...