ok... i've done this to my l03 a couple times (ok more than a couple, like 20 times) in the last few months. I havent changed the oil in about 4300 miles, and it does have some noise from the bottom end as far as i can decifer...

right now you're going... what the HELL is he thinking...

well, im thinking my 355 needs to get off its engine stand where its been for over a year and get into this car, so my excuse will be blow the l03. I am thinking, why the hell hasnt the engine blown yet, and finally, WHY THE HELL is the engine still pulling and not out of power/missing or anything at 6700 rpm when i push it up to 2nd gear it PULLS into 2nd gear. WTF!??

these things just arent strong enough to kill themselves are they?

 

Ive seen 6500 a few times ...

 

I take mine to 6000 on the stock heads and cam because I am stupid and have zero desire to keep the 305. My buddy takes his to 6500 with vortec heads and LT1 cam. 6700 is just crazy. But it sure sounds cool

 

I've done it before, but not on purpose, lol

 

You might want to install a good Autometer tach in it. I bet you arn't tunning quite the rpm's you think you are. I've been trying to find out what kind of trans problems my brothers 91 Vette has, during a test drive I just stomped on it and held it to the floor till it shifted into second, the thing didn't shift untill 6500rpm and it was still pulling. This is with a stock 350tpi that should run out of steam at 4500 to 5000rpm. Needless to say his tach is way off. My tach in my 91RS is about two to three hundred rpm off at 70mph in overdrive so I,m sure it would be at least 1000 to 1200rpm off at higher rpms. We all wish our lo3's were hi3's and could spin them to oblivian like the 302 of old.

Steve

 

Most engines probably would've suffered some damage after that many times up that high but not our trusty 305 with its sub-par power levels. Gotta love it

 

GO LO3, IT'S YOUR BIRTHDAY, GO LO3, IT'S YOUR BIRTHDAY

 

A 305s bottom end will withstand more rpms than a 350 built the same way. Why??? The 305 has a lighter crank and pistons so there is less mass spinning. This is assuming both have the same crank, rods, and number of bolts on the main caps. I spin my 1983 chevy van 305 to 6,500 all the time in 1st and 2nd. I am going 90 in 2nd with 3.42:1 gears before it shifts. I just can't get passing gear 2nd @ over 50, although if I just hold it down from a stop it revs way up. Then again my little 305 was built and balanced to run up to 7,000 rpm or so. It is a factory 4-bolt main, full forged setup (don't ask it came that way). Canadian medium duty truck/marine engines came with this setup. Sounds a little hard to believe that a L03 will pull that high. I always thought they ran out of steam @ 4,400 rpm or so.

 

ill get some video of it with audio so you guys can analyze...
if 6500 might = 5500, i guess ill just have to take it to the max and see if anything blows...

 

Hahahahaa thats funny!

 

Technically, I believe just under 6,400rpm is the max the ecm can handle without hacks in the chip......I only know because I hit a "rev limiter" at that rpm (per winaldl) with the 383.

Anyways, I say go for it and see just how strong the l03 bottom end is.

 

when my old motor blew up the factory tach was begged

im guessing it was turnin 7500 to 8000 when the rod bearing spun

 

You would be surprise at what kind of rpm's the bottom end of most motors will take.305's have small pistons compared to a 350 so that makes them a little more tolerant of rpm's, their cranks are identical other than the main bearing size. The valvtrain is usually what gets you into trouble. Valve float is usually what limits your rpm, with the round cam thats in these lo3's you probably won't float teh valves till way up there. I was able to consistantly run my HO 305 in my monte to 6500 before I yanked it. Ends up the timing chain had stretched almost 1/2" and caused the timing to be advanced a crap load, no bottom end but she would pull pretty far into the power band.

r90: The ecm will go much higher than 6400 rpm, thats just where most of the tables stop, the ecm will keep going but just use the last cell you were in. You also don't have a rev limiter in your car unless you put one in the code, there is a patch for that, my guess is your injectors are going static. I ran into this while tuning my 350. It would just plain hit a wall when the injectors went static, sounded very much like a rev limiter. I verified this by getting winaldl to spit out my PW and sure enough I exceeded the max PW at the same time I experienced the miss.

 

i know my stock tach is off.... so i shift at whats almost pegged, and i get the best ETs....


going by winALDL and the tach, ive estimated its on avg, about 18% off.... so if anyone wants to figure my RPMs, go ahead.... lol

 

Did a little data logging tonight and this is what winALDL came up with.

IAC 128 - Coolant Temp 187.3 - SPEED 88 - MAP 94.5 - RPM 5425 - TPS 97.7 - INT 128 - O2 0.769 - BLM 128 - IAT 68.5
This was in second gear right before shifting into third. The tach in the car was reading 6000RPM.


Steve

 

Why dont you.....

Pull car into garage, start pulling engine out. Then you will have a reason to put the 355 in there.

 

keep it in neutral and lay a brick on the gas pedal

 

im still in an apartment... if i had a house, with a garage...... o the beauty that would present...

 

I recently pulled up to about 6000 and bent a pushrod, bottom end is cherry though!

 

would that mean your rockers were set too loose?

 

I would say too tight actually, not sure though. If the rockers were tighter it would put more pressure on the entire valvetrain. I have to check today to see if there's any interference in the pushrod hole, I don't think there should be, especially with stock heads and an LT1 cam and stock rockers

Tony

 

Mine made power to about 7 grand, timeing chain sproket broke on me when i accidently reved it to like 8 grand and ****ed up my crank key so ya time for a new bottom end. But i had it runnin 6500-7000 all the time w/ no problemos.

 

Funny that you said that. I saw this video a while back where these two guys took a Mazda RX7 (old one) and the engine was having some issues...the car was in real bad shape body/frame wise and now the engine was going so they called to get the car towed to a wrecking yard. HOWEVER!! before doing that they decided they would put the car in neutral and pin the acceleration to see how long it would take for the engine to blow up. The Rotary engine lasted 9minutes 17 seconds. The Catalytic was on fire which was bad cuz it wasn't that far from the gas tank.

Bottom line...these guys were idiots. They just wanted to kill the engine, however in the process they could have killed themselves. If you really want to put a 355 in your ride instead of the 305, just do the swap and sell the 305. Either that or keep it as a spare engine. Don't bother trying to kill it.

 

Somewhere out there is one of us whose original L03 has 200k+ miles on it and is pretty well gone, or maybe it IS gone out to lunch.

That hypothetical person might not be able to afford a new or rebuilt engine, and would probably give his lefticle to get his hands on your "boat anchor", so he can get his car back on the road.

Think about that before laying the brick down.....

Of course, we did the same thing to a '77 Ford Granada 6 cyl.

It was still on the tow truck, revved like a sick coyote for 10-15 minutes till it blew a chunk of iron the size of a softball out of the block, and still kept running. We got bored before it had a chance to blow up......

......But nobody wanted the Granada, even when it was new.

 

just on screw the nut in the oil pan a little and say it rattled off if u want it to blow.

 

ok.... i want to kill it, but not COMPLETELY blatantly

 

I think this thread has just about worn out any technical value, and although funny, TGO does NOT hold itself or anyone involved responsible if you hurt yourself or damage your property. Thanks guys!!

Bruce (90RS305)

 

I was having issues with my 305 in my 86 Caprice missing a couple days ago so after finding it needed plugs, wires, cap and rotor we first did a compression test to make sure we weren't putting money into a screwed motor. Found 150psi every cylinder. This motor only has 130k on it but its been run out of oil a couple times, run low or overfull other times and gone over 10k between oil changes for a while when my friend didn't know any better. He also started it up cold and put his foot to the floor and revved it up to about 5000rpm a few times when it was below freezing out. Car has also been detonating since my friend bought it with about 75k miles up until I bought it and started running 91 octane. Also found out the lifter tick i thought i had was really just the heat riser valve clicking. I don't know if these engines can be killed legitimately without some kind of act of stupidity done to them.

 

we have tanks... isnt it great - maybe i should put my 355 in my truck and rebuild the 305 .... no? ok, fine, 355 in the camaro

now if the 305 will handle this random abuse... how much power do you think a built 305 could handle and still last about 50k miles... supercharged with nos and good internals etc...... 400hp...

is it the 305's bore and stroke dimmensions that help in not destroy itself or is it the tiny little cam and low hp output of it? both?

 

Everyone I talk to around the office says that the 305 has some seriously untapped power. My buddy had a Monte Carlo with 305 and he did some upgrades to it (heads, cam, exhaust) you know...the fun stuff. He managed to get that engine running about 300hp at the rear wheels.

I say just swap the 305 for your 355 and put the 305 on the classifieds here. I am sure someone will see it and want it.

 

^ HAHA especially after they know its seen over 6000rpm about 20 times. LOL

 

Nitrous time.

 

Probably the low power output. The stroke is the same as a 350 but the pistsons are a tad lighter I think. Why not jsut take the 305 out and swap in the 355? Who cares if its still running or not. Lol... either way its still jsut a pile of useless metal sitting on the garage floor.

0h, i second that, give it a 250 shot or something. That should kill it in a hurry, along with possibly the rest of the drivetrain. Of coarse, the 355 will probably do that if given enough time so why not kill it all at once so you can put somehting good in

 

I know a guy that had an old oil burning 305 LG4 in his 86 Cutlass and he ran a 210 shot on it. It ran a 16.4 off the bottle and a 13.8 with nitrous. He ran 3 bottles through it and it never blew up so he just pulled it and put his new 350 in.

 

Didnt think of that, even with the nitrous its only around 350 some odd horsepower. Well within the saftey limits of a SBC.

 

why does it seem these **** burners with 120 horsepower are fast when they push to 7000 rpms? I took a ride in my friends Saturn and I was like wtf? Even though it only had 115 horsepower how could it seem a little quick?

 

Powerband and gearing. A BUILT 350 can make 500 HP @ 6,500 RPM. A 283/302 turn to 8,000+ RPM if built properly and typically ran 4.56-5.12 gears. Talk about some revs and gear reduction. Come to think of it the new LS7 is doing the same thing. They increased the rev limit over the old LS6 to keep it in the lower gears longer therefore giving it more Rear Wheel Torque. Just as spinning my 312 to 6,500 does with 3.73 gears. I trap in 2nd gear! From 40-90 I am in 2nd gear.

 

Wow..........back from the way dead.........

 

i def. need a 342 gear.