i'm looking into de-stroking my 305. i've read that a 265 crank will fit the 305. i've looked on ebay and found this: http://cgi.ebay.com/ebaymotors/ws/eB...sPageName=WDVW the casting number is 3815822. will this fit the 305? i want to destroke the motor to create a high revving motor for turbocharging. thanks.

Small journal.

305 = large journal.

Nope, won't fit (unless you can find some bearing spacers).

Turbo the 305. Don't bother trying to destroke it.

Or, get a small journal 327 block and put that crank in it. 302 cid (plus whatever additional overbore is required for cylinder wall cleanup). That would produce something worth having.

I vote for the 302. They rev to the moon. But its no replacement for displacement

yes there is. boost.

Late model 265 crank and rods will fit in a 305 block needing not even a piston change. Makes a 267.

actually it makes it a 263 ci, and it wont fit like they said its a small journal, 305 big journal, but if u use a 267 crank that will work, but not a 265, im taking class in engine machining and we were just talkin bout this.

http://thirdgen.org/techbb2/showthre...hreadid=274673

Same theory on destroking.

There is a LARGE journal 265 crank!!!!!!!!!!!!!!
The late model 265 (baby LT1) crank is a LARGE journal crank. It has 5.94" rods in it which is exactly half the difference in the stroke which puts the piston at TDC. With a .030" overbore (typical clean up) a 305 is 267 cubic inches. I helped build one to put into a 1978 malibu with a T-56 and 3.73 it was a heck of a screamer.

Late 1 piece seal roller 305 Block .030" over
1 piece seal 265 L99 Crank (3.00 stroke)
L99 5.94" Rods,
HO 305 Flattop Pistons
305 Vortec heads
LT4 Hot Cam

Why would you go through all that work if you could build a 4.155" bore 3.00" stroke motor for about the same money?

It equals about 325cid.

But why would you ever want to make less power? Larger motors will always make more power than a smaller one.

im looking to make up for the loss in cubes with boost, besides cubes dont add as much power as psi, and boost will be more practical on the street(better mpg, more driveable cruising power).

but i am also looking into a 400.. i'm just trying to decide which route to take.. lt1, lq4(5.3), 350, 400, or stay with the 305 and do something different from what everyone else does. i want it rev RELIABLY to or past 8k. i know that can be done with a big cube motor too, but i think its more reliable when you keep displacement down, and piston speed low.

Go with a LS2 motor and add LS1 electronics. With boost that thing will make unbelievable power!

lol... thats funny, if im gonna go with an ls2 i might as well just get the c6 wrapped around it too. im looking to spend less than 5k all together on just engine work(ill do the work myself).. last time i checked the ls2 cost like 6k by itself. seriously if i was going for an ls1/ls2, i dont think i would have a 3rd gen. the closest to an ls1 i want to get as an lq4 or an lq9 out of the trucks, they're iron blocks, and the 5.3 can be stroked to 5.7 i believe.

Yeah just for with the the iron block 6.0 liter if your gonna do that, and don't care about weight! But the LS2 is the **** 6.0L all aluminum! **** yeah! The LSx motors are the ****ing ****!

an engines ability to suck air in and push it back out has more to do with it being a high RPM preformer than a short stroke

yea. thats what the turbo is for. otherwise n/a bigger cube engine>smaller engine.

anyone know a caprice messageboard or something where i can get the l99 crankshaft?

Bigger engine with forced induction > smaller engine with forced induction

Exactly. On the typical SBC the valvetrain affects RPM potential way more than stroke will.

no. why do you think the most powerful boosted engines are mostly all small displacement. let me rephrase that, why do you think all of the RELIABLE street driven high boost engines are low displacement. smaller, beefier engines can take more boost, smaller cylinders can take a beating more than huge *** coke bottle cylinders. **** if in 1987 formula 1 cars with 90ci could get 1400+hp, i think a 265" v8 will be more than enough, especially with all the advances in turbo technology.

but i see your point though, a bigger engine will make more power with the same setup, i just see no point to get a bigger engine, im not planning to make over 2000hp, not even over 1000.

[quote]Originally posted by Fast355
[b]There is a LARGE journal 265 crank!!!!!!!!!!!!!!
The late model 265 (baby LT1) crank is a LARGE journal crank. It has 5.94" rods in it which is exactly half the difference in the stroke which puts the piston at TDC. With a .030" overbore (typical clean up) a 305 is 267 cubic inches. I helped build one to put into a 1978 malibu with a T-56 and 3.73 it was a heck of a screamer.[b]

actually fast355 i hate to inform u they never made a 265 large journal, they only made the 265 for two years 55-56 and they were small journal. they made a 267 crank which most ppl confuse with 265, belive me i've argued this many times when i thought i was gonna try this with my 305. also the 267 crank was never a 3 in stroke its thee exact same stroke as a 305 and 350, 3.484 stroke. it was a 283 crank that they used to make a chevy 302.

Do us all a favor.

When you abandon this project, come back and let us all know how much money it wasted, and how much power you got out of it or how fast it went.

Meanwhile, results are real; and spank-off about "I'm gonna do this someday" is just that. Once it's actually accomplished, come back and show how wrong everybody was.

This is some of the craziest stuff i have ever heard! Insane!

show me where i said i was gonna do this some day? i asked if the crankshaft would fit, i didnt say i am gonna do it.

and whats so insane? look around, almost all high horsepower boosted cars are low displacement. when was the last time you saw a big block turbo cruisin down the street?

If you're not going to do it, then all it does when people post this, is start a bunch of arguments.

And the reason you don't see turbo big blocks is because they're BIG BLOCKS. A turbo isn't necessary to enable them to be traction-limited 100% of the time in a street car. After all, your traction limit is all the power you can possibly use; once you get there, you're maxed out. You can build a mild-mannered one that will last hundreds of thousands of miles, and still run under 12 seconds all day long. You run some high-stung little bitty motor with lots of boost, and you won't see that kind of mileage; especially not without LOTS of maintenance. Look around, get a reality check, before you let your hallucinations substitute for real-world experience.

calm down, no one is starting arguments. as a matter of fact your the only one that seems to be offended by this post.

Really....

Seems to me the whole discussion has gotten rather heated, as this always seems to do..... everybody who has no experience in the matter seems obligated to weigh in on it and educate us all. This one is no different.

For being a machinst, you sure don't know your engines.

He's right.

The baby LT1 (L99) is a 265 CID engine with a 3.00" stroke and a 3.75" bore.

http://www.mortec.com/borstrok.htm

The problem is it has to be used with a 1 pc rms block. It can't be used on older 2 pc rms blocks.

So.... if the 305 in question is a 1 pc rms, then it can be done.

If it's a 2 ps rms block, just get a crank from a 307 and make a 285. Or bore the block .030 over and make a 290 V8.

Anything can be done with too much time and a whole lotta money.

the statement made is certainly correct. you can use the crank (3.00 stroke) and rods (5.94) legnth without even having to change pistons with a 305. i was at one time looking to do this for a customer. we would have simply been doing it for testing reasons though as the only way this would be a successfull project power wise would be to poor boost to it. the L99 was made from 94-96 and was a standard large journal one piece rear main crank. rather than going through the work of making a different pin height piston the boys at gm simply made the rod longer which made for other handy swaps. if you bought a 4 inch bore one piece rear main block you could use the L99 rods with L99 crank and end up with a fairly long rod/stroke ratio 302 without having to buy special pistons. in effect the destroked 305 isn't going to make much power though. you may be able to get the hp numbers up there with a decent 305, but the torque loss from the short stroke would make for a terrible driver. if you were class racing and there was a cubic inch limit to around there would be the only reason you'd want to actually do this engine other than for reasons of just playing around. built properly though it would get pretty decent fuel milage.

The truth is, the reason most "boost engines" are small, is because they usually have a displacement restriction and the boost is permitted.

If "small & boosted" was the way to go, I wonder why the AA Fuel Dragsters all use big engines (with their roots blowers)? I guess the fact there is no displacement restriction has nothing to do with the fact they are using a LARGE ENGINE.

Also, I guess my buddy's 383 with solid rollers has nothing to do with the fact that he still makes power at 7,000 rpm.?

But, it's your money. Spend it as you wish and enjoy.

Seeing that statement reminds me of a car I saw on a honda board when I still owned one. It was a professionally campained turbo'd 'honda civic' 4 cylinder (all custom stuff) with rediculous looking huge drag slicks and skinnies mounted the wrong way around that ran mid 8's. If one where to show up with that at a meet where guys are running turbo'd/SC'd 3.8's, 4.3's, 350's, 400's, etc. and not only would they drum her/him out of town with their laugher, but a number of them would be able to meet or beat it with their cars that they put together themselves.

Its a simple fact of life, the sky is blue, grass is green, water is wet, and larger displacement engines have the potential to move more air/fuel through themselves, thus making more power.

some of the big boy cars that run high boost are also doing it for the rod/stroke ratio. they still run the large bore, but run the shorter stroke for durability reasons. in order to keep the rod/stroke ratio in the desired range as you add stroke to an engine the rod just keeps getting longer and longer. the longer a connectig rod is the more chance it's going to have at bending or breaking under higher cylinder pressures. in order to compensate for the less cubic inch the boost is in turn cranked up even more. long stroke motors and high boost are often a breakage waiting to happen. they aren't going for small cubic inches normally though as you'll see with the bore sizing. it's not uncommon to find big blocks with cubes in the 3xx. the large bore allows for large valves and still gains the cubes while the bottom end is assisted by the shortened stroke.

thanks for the informative replies. isn't a longer rod more durable though? since the crankshaft puts less of a "side load" on it.

laugh at a guy that runs 8s? must be some fast *** cars in your town. seeing a big block chevelle get its door blown off by a beater civic is even more funny.

i've read that turbos like stroke because of thermodynamics or something like that. and stroke is more fuel efficiant.

8's are very fast, but what caught me as funny is that this was no civic. It was little more then a body stylized as a civic with a complete custom tube frame underneath with all custom hipo parts. That car was definatly a high $$$ operation judging by the sponsorship. Yet, there are people who have single-handidly put together V6 and V8 cars that can easily match what that one runs. At the time, that car was billed as teh 'funny car' of 4 cylinders, yet it seems to run double the times that V8 cars do.

the key word(s) here being "i read" as in you ain't done **** but you've got a subscription to all the hot rod mags printed.

no. i read that while doing research on turbocharging, its in Maximum Boost, which every turbo guru read at least once. and no, i dont have a single subscription to any magazines ********.

Watch the rags, sometimes they outright lie on purpose.

In a forced induction application the small stroke is desireably for high rpm operation and the small bore for its resistance to detonation. Built right a destroked 305 could easily and reliably rev to about 7,000 and make over 500 hp (2 hp/cid).

I watched a friend build one after we speculated about building one during a bench racing sesion. We figured that since all the basic measurements for a 305 ( except bore) were the same as a 350, why not? He needed to replace the blown up 305 in his 1981 2dr malibu. To keep cost down we use a complete rotating assemly for a 265 LT1, even including the 3.75" pistons, just reringed them. The block was a late model 305 roller cam block with a one piece rear seal. The block was bored to 3.75" and new bearings were installed. We put a ZZ3 roller cam into the engine. The heads were mildly reworked casting # 14022601 305 heads with 1.84" intake, 1.5" exhaust valves, and 53 cc chambers, gasket matched, bowls blended, casting flash removed, and good valve springs. On top was a spreadbore edelbrock performer RPM and CCC quadrajet. The timing was run by the factory HEI EST distributer advanced 4*. It was backed to a T-56 and 4.10 gears in a 1981 Chevrolet Malibu. All I can say is from 2,000-7,000 in 1st, 2nd, and 3rd that little car could scare the **** out of you. By the time you hit 7,000 in 2nd the 85 speedometer is pegged. In 3rd I would say you were easily over 130 by the time you hit 6,000 rpm. This car put out 325 RWHP @ 6,400 rpm and 280 ft/lbs @ 4,800 on the dyno in 4th gear. It consistantly traps at 115 mph in the 1/4 but ET stinks as it is only in the low 13s due to traction on the stock size street tires.

That MPH is good for low 12's or high 11's with a good tire. Why would he go thru so much trouble to build up a 305 and not put a decent tire on it?

The 350 rod/stroke ratio is very reliable, it's 1.64, my 388 r/s ratio is 1.6

you're getting 325rwhp out of 267 cubes and that mild cam?

you're trapping 115 with 325rwhp with it in a malibu only using 1rst, 2nd, and part of 3rd gear?

in my 6 speed camaro to get 130 i'm not even sure i couild have pulled that off in 4th by 7k. how with a 4.10 gear are you getting there in 3rd?

Man...destroking an engine that's already crippled.

You need a bumper sticker of this:

Not just an engine wanna-be, but a turbo wanna-be...and a rude one at that.

Every Turbo guru? Who pray tell?

Maybe you should, then you wouldn't be so stubbornly stupid.

You are arguing what you've read against guys that have built. Remind me again who the ******** is?

YOU. With a capital D.

Sweet. So I'm a step above ede! Take that old man!!

So we have no idea who your turbo 'gurus' are. You really need to get those subscriptions sent in boyo. Then you can maybe at least pretend better and maybe have some info to post.

As for displacement issues with the turbos, know why they make turbos in different sizes? Ever hear/see/build a dual stage turbo set-up? Have you ever considered pondering diesals? May help you understand a little of what people are trying to tell you. Then again, maybe not...

And you need a bumper sticker of this:

<a href="http://server5.theimagehosting.com/image.php?img=itakeitinmyass_bumpersticker.JPG" target="_blank"><img src="http://images5.theimagehosting.com/itakeitinmyass_bumpersticker.th.JPG" border="0" title="The Image Hosting" /></a>

I kinda like this destroking a 305 project. It would be fun for something NA for someone with a lot of spare cash. For a turbo motor you want STROKE, because stroke means exhaust velocity, and better turbo spooling.

umm. yes i know there are diesel motors making like 5000 hp, but what the hell does that have anything to do with a street car? all you do is post up useless **** that had nothing to do with what i asked in the first place. is that how u get you post counts up?

and thanks all that actually answered my question, instead of giving me some useless s h i t about diesels and different turbo sizes.

will somebody lock this thread already!

The HP has nothing to do with it, I said ponder them, generally. You don't even get that. If you put my posts in context with your questions and belittlements they make loads of sense to those who aren't simpleminded. This quote seems to fit rather well in this thread... :shrug:

Bailiff!! Whack His Pee Pee!!!