As most of you know, I don't exactly have a third gen. It's an 84 monte SS. I always used to joke that it had an idenitiy problem, and thought it was a camaro. Since it had 16" RS wheels and TBI. Well the transformation is going to be complete in a week or two. My old 350 gave up the gohst and lost oil pressure. I was going to build something wild, but with a 98' subaru, a wedding, and a house to pay for that just isn't going to happen. A friend of mine has an LO3 he's going to sell me cheap......thats right I'm actually paying for an LO3. The transistion from about 260 whp to about 200 is not going to be fun, but I'm kinda excited about the fact that I should be able to get in the very high 20 MPG range.

So here's the tech, what do you guys want to see done with this motor, do you want to see the difference between a stock and a 454 TB? How about exactly what needs changed in the chip for a LT1 cam? How about a baseline chip for the new U-tbi code? That way you have something to start from.

It won't be completely stock, mods as followed

Stock swirl port heads
stock cam
performer RPM intake
454 tb with FP turned way down (well stock anyway)
shorty headers
2.5" true duals through warlock mufflers
electric fan....most of you already have that

may upgrade to an LT1 cam in future (because it's cheap)

 

Port the 187s or switch to 081s. The stock cam is a wimp, ditch it. The LT1 cam would be cool but the LT4 would be cooler. You might go the same way as me and step back to a hydraulic flat tappet. I am thinking L82 HO 350 covertte cam. The california only 1980 and 1981 corvettes came with a LG4 and that cam. They were rated at 190 NET HP from a 305 in 1980. That would be one of those sick 8.5:1 compression, horrible port, 1.72" and 1.50" valved monsters. Now think of that same cam in your L03. Mine finally broke 300 RWHP through the cut-outs. 270 through the mufflers. I am getting 17 MPG around town even after the 3.73 gear swap. Haven't taken a highway trip yet, but I am expectin about a 2 mpg loss back to 20 or so.

https://www.thirdgen.org/techbb2/sho...hreadid=320984

 

Here are the DD2000# for my proposed creation. Stock 187 heads, stock TBI, HP exhaust, and compression modeled.

RPM------------HP-----------------TQ
2000-----------96-----------------253
2500-----------128---------------268
3000-----------161---------------281
3500-----------192---------------288
4000-----------219---------------288
4500-----------242---------------282
5000-----------255---------------268
5500-----------253---------------241
6000-----------239---------------209

Or roughly 210 RWHP and 240 ft/lbs

Want more open up the heads or switch to ported 081s (modeled from my ported 601s)

RPM--------------HP---------------TQ
2000------------108--------------285
2500------------140--------------294
3000------------170--------------298
3500------------207--------------310
4000------------241--------------317
4500------------270--------------315
5000------------289--------------303
5500------------288--------------303
6000------------273--------------239

This is roughly 235 RWHP and 260 ft/lbs torque.

 

well ive been reading and dont alot of people have a problem w/ back fire and stumble w/ the rpm manifold due to limitations in the code of some sort cant remember the whole story but it was explained someplace...now of course this wouldnt apply w/ the upcomming U-TBI code thats comming but its still in development isnt it?? cant wait to see what u come up w/ as u know im in the process of building mine up i have 081 tpi heads im porting now, a lt1 cam, 3 inch cat back, and im saving for my headman lts, edelcrock tbi intake, ultimate tbi, and 55lbs injectors.

 

You can get around the backfire/stumble by using the 7747 Truck ECM as the AE routines are better. I used a a performer RPM with TBI on top on my 305 headed 355 for a while and it ran nearly perfect.

 

i will be running the edelbrock tbi for ease of installation so i hope i dont have that problem and it wont matter once they come out w/ the lockers/hud and U-tbi code....i was just tryin to give him a lil heads up cause i just remember reading that in a post once.
John

 

As in the edelbrock TBI intake? The 8746 is for all purposes a MAP only based AE. You could disconnect the TPS and the engine would not bog under acceleration. On a 7747 it dogs real bad off-idle with the TPS disconnected. The 7747, 8747, and 299 all have immediate fuel from the TPS and then some more from the MAP. The fuel tends to drop out of suspension pretty easily when you crack the throttle open, which gives the lean stumble. The TPS helps by giving more fuel the instant the throttle cracks open, vs. waiting for manifold vacuum to change. It is a much quicker delievery. Were still talking 100ths of a second though.

 

i got u and that does make since...and yeah i was talkin about the edelbrock tbi intake. thanks for the explanation. what about the table for pump shot vs tps?? does it not help to fill that gap and a quick hit off idle?? im just tryin to learn some of this stuff for when i start tunnin very shortly although i will quit changin the subject in his thread sorry.
john

 

When you actually look at the code in the 8746 the TPS pumpshot is very delayed. More delayed than the MAP. Works well for lower emissions on a stock engine but causes problems on a performance engine.

 

Well, I would love to do a head swap or some porting, but the problem is I'm getting married on the 29th, and I HAVE to have the car running by then. My fiance and I both have 84 montes believe it or not we had them before we even met. We really want to have them both there at the wedding. The other problem is that I don't have alot of time, or money. Between working and building our new house I'm going to be lucky to get an hour or two a couple evenings a week. So a quick cam swap while I switch over motors would be ideal. Fast, you have to remember that the l-69's in the SS's got the vett cam stock. I liked the power band, and the duration numbers where much like the LT-1 cam. The only problem I have with a bigger cam is that their expensive and I don't want to mess with different springs or any machine work on the heads. I'm only going to have 150$ in the LO3 so a 200$ cam doesn't make financial sense at the moment.

As for tuning issues, the RPM intake and huge TB would require some changes, but it's completely tunable with either ecm. The 746 does draw out the TPS pump shot, but thats changable, just gotta know where to look. I am running a 747, and will be switching over to the U-tbi code when it comes out.

I also have an older low profile single plane that's going to be fitted for 8 injectors over the winter. I think I may have the perfect MPI vs. TBI setup come spring. I'm planning on using the BB TB on the MPI setup, so it would very easy to run each setup back to back. The motor I was wanting to build this winter was going to see some not so natural aspiration in the future that would completely surpass what TBI was capabable of. Then again I was looking at an LS-1 6-speed combo.....never enough time or money.

Any one have a cheap LT-1 cam they want to sell?

 

The L82 cam is not the one that cam in the L69, that was your standard L81 350 cam. The L82 cam is the one that GM should have put in the L69. It has 224/224 @ .050, .450/.460" lift on a 114* lobe center.

 

Ohh.... didn't know that. Yeah that cam would work with the stock springs. Hummmmm.

 

Neither do I.

Subtract Subaru, add 3 kids. Now you know why I avoided another optispark LT1 engine and jumped retro into the TBI. Power is fun but breakage and too many opti/waterpump jobs gets old fast. And you'll (eventuallly) get a return on the house investment -- you won't by sinking a lot of money into a 20 year old car.

Look at what Dewey316 has done with his stock-headed LO3: 208 rwhp. If the heads were as bad as claimed, he wouldn't be put down that at the rw nor would he have run mid 14s. The theme for you IMO should be to stay cheap and see how far you can go. Keep them, and port them if possible before installation. Get a spare factory TBI intake manifold and port that too. Stay cheap. If you can get a 2nd set of heads, 187 or 081 or other, port those while you drive the LO3s.

Lo-tec went mid 13s on stock SP heads and the usual mods in a 350; you might be able to go high 13s or better with a ported LO3. So long as the rings are good and the valve guides not excessively worn, you ought to get mid to high 20s mph highway. Check the condition of the engine before you buuy/install if possible.

 

Cheap is the theme, I'm going to checkout the motor tonight. It's sitting on an engine stand so I can't do much other than turn it over and listen for funny noises. Hopefully it still has the plugs in it and I can tell if it's burning oil. It's a close friend, so if the motor is DOA he'll refund my money no problem.

I say the motor will be put in just like it is, with my headers and performer RPM and 454 TB. In theory the TB and intake are way too big for a 305 and mismatched to the cam and heads, should be interesting to see how it reacts. Once everything is in and running, I'll definitely entertain the idea of a cam and head swap. I also have a 2000 rpm converter, this thing should be able to blow the tires off. With the 350 it didn't really scream till 3 grand so you could get it moving before the power came on.

If I can eventually get this thing in the low 14's I would be very happy. The fiancé said this was the last half *** motor job I get to do, the next one has to bad *** and done right, LOL maybe that’s why I'm marrying the girl.

 

Since it's TBI, it might not matter that you use the 454 unit, so long as you can get the idle controlled and the fueling set up for a stock 305. Dewey, IIRC, only had a cam swap plus the usual external engine mods so it sounds like you are poised to repeat what he did. A cam swap before engine install would be easier IMO, if you can find one ASAP.

 

I couldn't find diddly squat on e-bay but I have 3 leads on cams under 50$ from the thirdgen classifieds So I'll probably have the LT-1 cam in this motor. I just need to find some cheap springs and a timing chain and I'm in buisness.

I'm going for the record with this engine swap. I can have the motor out in 1.5 hours, should only take 2 hours to swap the cam in and swap over my intake and headers to the LO3. Then another 2 hourse to reinstall. It seems like the bolts see me coming and fall out of the motor. That can't be a good thing.

 

Cheap springs: use 94-96 Bcar LT1 springs from GM. Bcar owners often use Dal at Vandevere for internet parts sourcing:

lockitup @ bright.net

(877) 448-5451

Or go with your favorite GM internet parts source. Also get a price on retainers + locks for the above too (so you can dump the exh rotators).

 

I've gotta friend that can get me GM parts at cost plut 10%. So I'll probably go that route. I'll need some spring shims to make up for the exhaust rotators. You think GM will have those? The local machine shop charges too much for them. I'd rather not have to tear down the heads on my current motor just for the shims, If I do I'll probably just use those springs, their actually pretty expensive springs and are good to over .550 lift. I'll have to measure and see what the heads are good for.

 

Project L-cheapo exploded to life 11:30 PM Saterday evening. The beast vocalized through open headers with an authoritive howl that would wake the dead, well it did wake the neighbors. I'll update tomarrow when I have some more time

 

Can someone give me the idiot version as to what the U-TBI is and will allow us to do? I know it's some PROM mumbo-jumbo, but that's it.

 

Why o' why don't you live close to me? I have a 95k mile LO3 sitting on an engine stand that I'm having thoughts of playing with, even though I don't have a car for it. With you in the area I would have this thing set in no time.

 

Whats the final combination and how does it run?

 

Project L-cheapo is basically a stock long block LO3 with the following upgrades

High-pressure oil spring
96 LT1 cam
upgraded springs with 110lb seat and 280 lb open pressure
Performer RPM intake
454 TB with 70 lb/hr injectors
½” open spacer/adapter
1 5/8 mid length headers
2.5” dual exhaust with x-pipe and warlock muffler that dump at the rear end
Of course DIY tuning on a 747 ECM

I just backed the FPR down a few turns and started it up. It ran fine, idled like a dream with no hint of a lope. All this with my last iteration of the 350 chip. I took it for a quick spin on Sunday after chasing some problems, which I’ll get to in a moment. Ended up I went too far with the FPR and was a bit lean. My pump shot was way too much for this engine, it would puff black smoke every time I would snap the throttle. I set my initial timing to 6 deg and then realized that the chip was set at 0* so I had way too much timing for this engine. I’m going to pick up the car from my parents house (aka the garage) tonight and start doing some tuning. On it’s maiden voyage it ran fine once in closed loop, it pulled decent for no tuning, but there is a LOT left in it obviously. The motor sounds much quieter at idle but about the same once under way. It also is much smoother than the 350, probably because of the cam.

Now for the problems I ran into during the build. First, the damper was welded on to the crank with rust. I stripped the pulley bolts and had to tap them to the next size bigger to get the damper off. Then the lower timing gear literally pulled off with finger pressure…not good. The new timing gear pressed on fine, so I guess it was just a problem with the stock one. The motor was completely full of what I thought was sludge from neglect. Once I started cleaning up the sheet metal I quickly realized it was just gelled oil. It would easily wipe off with a rag where coked on oil from lack of changing is usually stuck for good. Which leads me to believe that this motor has sat for a long time. This was further reinforced by the discover of the most retarded problem an engine could have…I have an oil leak in the side of the pan. The motor had a fresh coat of paint on it so I didn’t notice the rust till it started spewing oil all over the ground when I started it. It’s a pinhole, but is enough of a leak to cause problems. I found some sealer at the parts store that’s supposed to be for gas tanks and oil pans. I slathered on two coats and let it dry. It appears to be holding, we’ll see when I get some miles on it.

Gunny, The U-tbi code is Rbob’s own code that basically fixes all the little annoying things that GM did to either comply with emissions or just because they didn’t know of a better way at the time. The board that they are going to be selling is basically a lockers board that intercepts what’s going on in the ECM without using the on board processor to spit it out the ALDL. It also by passes the stock chip as well as the on board rom that holds the other half of the stock TBI code. This lets you run your own code, hence the U-tbi code.

 

Well the last week has been.......interesting. On Monday we got hit with a freak snow storm that knocked out power for most people in WV, the problem was there were still leaves on the treas so the snow stuck to the trees and broke down trees like they were twigs. So me, my wife, the rehearsal dinner place, the caterer's house and the reception hall all were without power.........then it went down hill from there. We still ha 90% of the prep work to do for the wedding without power. We all moved in with family and friends and made do with what we could. We found out on tuesday that half of the guys tuxes didn't fit, and had to have them overnighted, we then found out the day before the wedding that my wifes dress didn't fit......she took it like some one ran over her cat with a mower. Her dad being the resourcefull type, came up with the fix, he made 2" extensions for her shoes which made up for the extra length of the dress. She had tried it on before, but never tried walking on carpet with the dress, the extra height got the dress up enough it wasn't folding under anymore. The power came on at the rehearsal dinner place the day before, and the reception hall scrounged up 3 generators and enough candles to light the place. Now for where project L-cheapo fit into this fiasco.

I got the LO3 swaped in weekend before the wedding, it ran fine. I had it 90% tuned in 2 chips, just had some WOT tweakinga and pump shot tuning to do. I had only ran it around town a few times in the evenings, and finally took it to work on thursda (100 miles round trip). On the way home from work I started to pull. the mountain that I have to go up right before I get off the highway to my house. About half way up it starts knocking somthing terrible and oil pressure starts dropping. By the top I'm floored doing 50 mph with 10 psi of oil pressure. I was able to get it home, but it sounded BAD, like every single rod was smacking the block. Remember this is 2 days before my wedding, and the monte HAS to be at the wedding. We both have identical 84' monte ss's and have had our cars since we were 16, way before we ever met, our plan was to drive seperatly from the church to the reception. I left the car sit till the morning of the wedding, my best man met we with 2 quarts of 90-w120 gear oil, we dumped it in and fired her up and luckily it started with just a slight peck. We jumped in and made a hail marry run for the church. It made it, the peck got louder as the oil thinned down, but never locked up. It then started fine after the wedding and made it to the reception, we were then able to do a tandem burnout in the parking lot of the reception before the engine stalled out....ahhh man if that doesn't sound ******* I don't know what does.

All in all the wedding went off with out a hitch, everything went perfect. My brother was able to drive the car back to the house after the reception. We had the subaru all packed up for the honeymoon and left from the reception. So thats where I'm at right now, we're in Atlanta enjoying midtown with it's art museums and fine dinning. We're going to Emeril's restraunt tonight. It's been a nice getaway, and nice to spend some "quality" time with the wife instead of the monte.

 

MonteSS, congratulations on getting hitched. Now that's a story you can tell the grandkids some day. Even your kids (you are gonna' have a few, right?), once they get older it is fun to tell them the story's about how things went, as you and the Misses' reminisce and laugh together (I think I'm showing my age).

Enjoy the time together while away from it all. . .

RBob.

 

Well, if you're going to throw a rod during your wedding, better that it's done in the engine (which can be replaced) than in the honeymoon suite.

I'll let someone else take "gear lube and honeymoons for $200."

CGs.

 

Awesome thread-
Congratulations and enjoy!
S-D

 

no record there. i've swapped engines in demolition derby cars between heats before. that is, removing/rearranging mangled sheetmetal so it will come out, getting the new one back in, and everything secured and reconnected. hell, by the time we got done, the stacks werent even cool enough to touch. we got it done in just under 40 minutes.

 

Ok you got me, it's a record for me....besides you only have a fuel line and one power wire in a demo car, and you can just hammer anything that gets in the way.


Well, I'm back and feeling rested. The monte is getting parked till it can get a motor done right. Strangly you can start it now and it doesn't even rattle. Something is deffinately screwy, I say the 90 wt oil is doing it's job even though the rod bearings are in the oil pan. I put a high pressure spring in the stock pump while I had the pan off, and the pump looked brand new. I don't know if someone had been in there and replaced the old one or if all the damage happened after startup. Like I mentioned earlier the motor was pretty sludged up and probably had lots of sludge in the oil galleys that starved a few bearings. Ehh who knows

The snow is going to fly soon and I have all winter to get it running again. I might just entertain my LSX with a t-56 swap idea again. I had a friend tell me they know where a good running 383 is that I could pick up for a decent price.....then again I had a "friend" sell me this motor. I really want to stick with TBI since it's what I'm comfortable with, but where I want to go with this car is going to be above and beyond what TBI is capable of. If I stay with TBI it will only be a step in a progression of bigger and better things to come.

 

you're forgetting starter wires, alternator wires, gauge wires (oil, temp, tach, volts), fuel feed and return lines due to the electric pump, plus the fact that its 250*+ while working on it.

 

Just dragging this thread back up to update where I'm going with my car. I tore into the old 350 to check it out.

When I pulled it I had 5 to 10 psi of oil pressure at a hot idle. The lifters were starting to collapse at idle from the lack of oil pressure. The sad thing was this is with a HV pump, and 20w-40 oil. I was also burning about 1.5 quarts of oil every 1000 miles. Cranking compression was great at 200 psi. I had the oil pump pickup fall off about 10k ago, but caught it pretty quick. I lost about 5 psi right away and slowly lost pressure over the next 10k.

The cylinders looked great, you could still see the cross hatch, this motor was bored .030 about 60k ago, and it got a fresh set of bearings about 20k ago when I wiped out a cam lobe. The bearings looked bad, but not totally toasted. There were obvious signs of the debris putting some deep streaks in the bearings and no. 1 main was just showing signs of copper on the bottom shell. I assume the lack of oil caused some galling and ate most of bearing clearances, and the motor just slowly ate itself over time. The back of the intake valves had some pretty nasty carbon buildup, so I assume thats where my oil burning is coming from. You could also wiggle the valves a good bit in the guides.

I think I'm going to just slap a cheap crank kit in it and get it running. I'm also going to port the non-SP 305 heads, get a valve job and get the guides done. This should get me in the neighborhood of vortec head performance for cheap.

I'm also going to try some more compression, since I was able to run 89 octane with 36 deg of timing, and 87 with that backed down to 34 deg. I usually run 93 anyway. The other reason I'm going to try more is because I found out my pistons are .045" in the hole.....ickk. Combine this with a .042 head gasket and a .020 head gasket shim (because I'm running 305 heads with flat top pistons) and you get a squish of about .107 with a compression ratio of 9.5 to 1. With a steel shim head gasket I can get my squish down to about .063, which would put me at about 10.65 to 1, which is a bit too high for my tast. So I think I'm going to try to open up my combustion chamber on my heads to about 62-64 cc's and drop that to about 10 to 1. Six cc's sounds like alot of metal, but if you think about it the valve relieves in your pistons are 4cc's so it shouldn't be to hard. The heads I have also have 1.94 intake valves, so their shrouded a bit.

I'm hopeing by closing up my squish clearances I can get away with the added compression without being timing limited. Now to sound like a hipocrite, I'm aiming to get 300 to the wheels, hopefully I'm going to be ditching the 700-r4 in favor of a 4+3 trans of of a mid 80's vett (if the deal goes through) which should help with the drivetrain losses. I was running 13.8's at 98 mph. I'd like to drop that down into the low 13's at around 102 MPH. I was also running 3.25's when I ran the 13.8, I'm now running 3.50's and hopefully the extra gear in the 4 speed will help with that nasty 1-2 bog that the 700-r is known for. The funny thing about this project is I'm going to have it all done for less than a grand.