splitface454

iTrader: (1)

I'm running 193's setup for my lift...no porting done. 9.7cr.

Fast355

iTrader: (2)

I ran a GM 846 or 847 cam, forget which now in an otherwise stock internal 1995 Tahoe engine and it ran best about 28-29* of total timing.

splitface454

iTrader: (1)

I wonder why I have such a sensitivity to timing??...at 28* the tone of my motor goes flat and I lose rpm and power, it just revs without any pull.

sootie007

Drumroll please.....Ok modded the distributor to locked timing and put 30 * in it...no ping , is it burning tire all through first as someone said - no , does it finally feel like I thought it would at this hp level ~ 250 yes but it takes forever to climb .....BUT I still feel there should be more torque and snap present here for this combo....it just doesn't feel like 300-320 ft lbs ish. I guess all that's left here to do is I could take it down to say 26 locked then all the way up to say 34 and see if there is any noticeable change.....it still ran 160 and no pinging...My EGR passage is not blocked however so the manifold floor is getting heated. This carb also has annular boosters which should have helped the low end .

Looking back at what I expected here with the 2.73 I should have simply run a Comp Cams extreme 4 * 4 grind at like 252 or 258-470 lift . I think I simply picked the wrong cam .

splitface454

iTrader: (1)

Try to back off to 26* and see what happens. I had the slow rpm climb to and that's what fixed it for me. I ran the 252xfi comp cam with TBI before I ran this setup. That was a torque monster.

sootie007

Sure will try it tomorrow 26 *and let you know......

SouthSide2

So do you remember how it performed before all your modification?
Just wondering if you think your ahead or behide on power and where.
Any fuel milage loss or gain?
I'm thinking you are so focused on all out power (like your big bad *** buick) you forgot its a sissy little 305 .

I did a cam change with a Compu cam from Crane cams and was unhappy with it at first.
I thought I would have all the power every were I wanted it.
Wrong.
Lost low rpm power.(idle / 1500 ) Not alot but I could tell.
I did gain power from 2000 to 4500 .

This was with a 1990 rs 305 cid t5 trans 3.08 gear.

I bought a totaled 1985 trans am and replaced the rear gear/axle to 3.27 and and it has disc brakes (liked the disc brakes).
I also put on the HO exhaust from the tpi 305.

Now I had something I could feel. It was alot work for so little gain but at the time that's alI I was willing to spend or do.

So you may need a better gear and/or stall converter with your set up.

Ultimately GM has supplyed you/us with the best all around setup for a 305

KILLemALL

iTrader: (3)

Did you install new valve springs?

Fast355

iTrader: (2)

Must just be these whacky TBI heads. When I cranked up my tuning laptop and dug into my older stuff, I looked at the swirl port head timing table on my oldsmobile HO 307 powered cadillac that had the Q-Jet. FACTORY STOCK the WOT timing map started at 28* at 1,200 rpm and ended at 34* @ 2,600 rpm. Very quick, short advance curve with a ton of initial advance. 8:1 swirlport head engine with a nice roller cam.

sootie007

sorry guys I have been away .......unfortunately I have experienced a few more challenges...............

I put the timing back to 26 degrees (locked in my case) as someone suggested and as I started out of the neighborhood the car totally and abruptly died. Literally it felt like someone disconnected the battery. I immediately restarted it and began driving it again then 3 minutes later the same exact thing happened. I got out popped the hood and looked at the glass site plugs -float levels and they are both fine hitting 50% of the carbs windows. Got in drove it again 5-7 minutes this time - then it died abruptly again. Limped home held the rpm at 1500 rpm in my garage in park and it died the exact same way -abruptly /cleanly again - NO backfires , stumbles etc ..... I think the +12 line to the distributor must have some sort of issue where the harness is heating up and dropping that voltage down far enough to where the HEI simply cuts out. I am going to run a +12 line directly to the battery to the distributor to test out this theory. Its not carb -because it dies so abruptly, cleanly each time - not stumbling etc . Just simply BOOM - its totally dead . Lights are all still on - on the dash ect . Restarts immediately each time.

I had this same exact symptom on a 70's car I had with a Pertronix conversion ignition on it - the previous owner had scabbed +12 off an inappropriate +12 wire and when the harness heated up after about 15 mins of driving the voltage dropped down to around + 8vdc and then the car would die abruptly the same exact way. It took me a month to find that issue on that car - but finally fixed it ...it frustrated me to no end , stranded me a few times and I wanted to simply get rid of the car .

So when I fix this issue then I can report back on the regression to 26 degrees of locked timing - down from 30 degrees locked.

This ones fighting me for sure lol.

jwfirebird

iTrader: (2)

thats how they are sometimes

sootie007

[QUOTE=sootie007;5769903]sorry guys I have been away .......unfortunately I have experienced a few more challenges...............

I put the timing back to 26 degrees (locked in my case) as someone suggested and as I started out of the neighborhood the car totally and abruptly died. Literally it felt like someone disconnected the battery. I immediately restarted it and began driving it again then 3 minutes later the same exact thing happened. I got out popped the hood and looked at the glass site plugs -float levels and they are both fine hitting 50% of the carbs windows. Got in drove it again 5-7 minutes this time - then it died abruptly again. Ran it home held the rpm at 1500 rpm in my garage in park just to see what would happen and it died the exact same way -abruptly /cleanly again - NO backfires , stumbles etc just died immediately ..... I think the +12 line to the distributor must have some sort of issue where the harness is heating up and dropping that voltage down far enough to where the HEI simply cuts out. I am going to run a +12 line directly to the battery to the distributor to test out this theory. Its not carb -because it dies so abruptly, cleanly each time - not stumbling etc and fuel is in the bowls . Just simply BOOM - its totally dead . Lights are all still on - on the dash ect . Restarts immediately each time and runs for x minutes then dies .

I had this same exact symptom on a 70's car I had with a Pertronix conversion ignition on it - the previous owner had scabbed +12 off an inappropriate +12 wire and when the harness heated up after about 15 mins of driving the voltage dropped down to around + 8vdc and then the car would die abruptly the same exact way. It took me a month to find that issue on that car - but finally fixed it ...it frustrated me to no end , stranded me a few times and I wanted to simply get rid of the car .

So when I fix this issue then I can report back on the regression to 26 degrees of locked timing - down from 30 degrees locked.

This ones fighting me every step of the way for sure lol.

Fast355

iTrader: (2)

[QUOTE=sootie007;5770104]Its hard to say as I have seen several different parts cause that issue with the HEI. Had a condenser go out that was causing the module to overheat. Had a module go bad. Also had a coil with an intermitent open when it was hot. Best bet is to get external power to the distributor and see what happens. It would be funny if the car suddenly picks up alot of power. On a TBI truck I had an ignition switch go bad and it would kill the 12VDC power to the transmission only and put it into fail safe while knocking out the speedo. Cycle the key and it would work fine for a while.

jwfirebird

iTrader: (2)

i had that happen to my jeep, gm engine, the module in the dist would fail when hot

sootie007

Yep , so to cut to the chase and avoid changing a bunch of ignition parts incrementally to get to the bottom of this -I just ordered a cheaper procomp HEI distributor for $50 off ebay and will be done with it hopefully ...will let everyone know what happens when I slap it in there .

KILLemALL

iTrader: (3)

I was wondering if you changed the valve springs,also could the dcr be a factor?
I am doing a similar build and I was worried about detonation.The ivc for the 395 cam is 24,what grade of fuel are you running?

Great thread and lots of info,thanks!

sootie007

Simply no time to finish this thing up....tonight I finally got a volt meter on the distributor +12 line and started the car - it only took 5 minutes for it to die ..front fuel bowl is full..... .when it dies the 12 volt line is still at 13.4 solid - so my theory about the supply line heating up and dropping the voltage down to an unacceptable voltage / shutting off the distributor is NOT what the problem is. So I will be dropping in the entirely new HEI distributor I got that finally arrived. Its probably the module inside heating up and simply dropping out. Will report back when I do .

I sold some stuff, so I am also ordering a rear gear and posi for it too as the 2.73 has simply GOT to go !

sootie007

Killem , there is NO detonation whatsoever - even with 32 locked timing it is dead quiet , rattle free and runs smooth / cleanly as can be . You don't have to worry about detonation here. Alot of guys chimed in here on timing and they all agree it can take a lot of initial and not ping. I didn't change the valve springs , the previous owner had the heads gone through within 5k miles of when I purchased it and I am not trying to set the world on Fire here ....I think the sloooow climb is simply due to the 2.73 .....My suggestion to you is run a hotter cam than this GMPP RAMJET -its just too docile...if I had it to do over again I think I would go with a comp cam at like 258 ish duration .4xx 110 or 112 or Mellings P/N MC1335 which is 252 258 .449 .460 (92-94 Vette cam) at least even for a daily driver.

Thanks, I have tried to make a good thread here for all to refer to when doing this popular swap. Including p/n's and prices when possible and all challenges along the way ......I hope to close it out after the distributor swap.


UPDATE 1-2015 later I pulled the heads off I discovered an .051 head gaskets on this engine ...that put quench at .076 ...LOOOOW compression .

sootie007

Ps FWIW after I purchased the GMPP ramjet cam I talked to Lunati and they recommended

20080642.......................259 263 416 447 on 112
or the slightly bigger

20080660.......................263 269 447 471 on 112

GMPP RAMJET to compare 246 256 431 451 109

For a combo like this their Tech support said he would lean to the smaller 642 cam . Another issue is I am not sure however if 305 TBI swirl port heads can handle the .471 on the larger cam without a spring upgrade ? Maybe some of the knowledgable gurus here can answer that question.

SouthSide2

Thanks for all your up dates and info. Very good !

I'm still wondering your thoughts on the was it worth it?

I Think GM refined this engine to maximize fuel economy and power as a daily driver. And did not leave much room for simple up grades to really make for greater performance. As so some my say these engines are crap. I say they are a very efficient,and perform just like their deigned to.

To make more power from this platform, the control of fuel...be it fuel injection or carburated is limited to how much said engine can flow or move air threw it, and how well or fast or efficient it can burn the fuel. With out changing things like heads it not going flow more than deigned. Also for more power from a small 305 as in stock from it must rev higher RPMs.

I Know you did not expect much from your swap. What do you think you gained or loss?

Oh yeah, ignition module malfunction is a sneaky Pain In The...

sootie007

Well if I could keep it running long enough to drive it and reflect I would let you know lol.....dropping the distributor in tomorrow night hopefully . Then I will take it for a spin and give my thoughts .........

Fast355

iTrader: (2)

You could always add power the way I did with my daily driver. Barely even notice it unless you are looking for it. With the 75 hp pills and 950 psi bottle pressure on a rich jetting with 2° of timing removed from 3,000-6,000 I gained 67 rwhp from 332 to 399 and gained 127 rwtq from 388 to 515. By far the cheapest power I have added so far.

sootie007

Well the good news is it WAS the distributor to blame for the instantly shutting off issue after heating up running for 3-5 minutes. I replaced the distributor with an Ebay HEI unit last night and all is well. I have timing set to 30* locked and will bring it down to 26 * locked timing to see if it makes any difference (slow climb issue) after driving it tonight. It starts great and ran for 20 mins straight in the garage -no issues. The bad news is it rained cats and dogs here in Orlando yesterday so I couldn't take it for a spin .....so tonight hopefully I will be able to drive it , tweak timing one time and give my final review of the TBI to carb - small cam swap.

jwfirebird

iTrader: (2)

this ebay one isnt adjustable? why lock it? if you set it at like 18-20 idle maybe 35 total that would be better overall

Fast355

iTrader: (2)

NOT with TBI heads!! 35° is way too much advance for them.

jwfirebird

iTrader: (2)

ok, i was guessing by what my stock vortec 350 map is, tbi is likely a little less aggressive must be

Fast355

iTrader: (2)

On the street and at the track, I have never even seen a vortec setup like more than 32-34* to make peak power. I ran my 8.8:1 350 vortec at as much as 38° timing on 87 octane and never had it knock, but power fell off above 34° total advance.

jwfirebird

iTrader: (2)

i have a all stock 99 yukon with a vortec 350 and i can watch live data. the idle advance is 20 and it will get to 36 if you put it in first and put the throttle about 3/4. i have seen the oem map and they took out a few degrees for wot, probably to save warranty trans work. people who tune them put it back and it has more power

jwfirebird

iTrader: (2)

stock for a truck is 9.5 CR

sootie007

"I Know you did not expect much from your swap. What do you think you gained or loss?"

So my final thoughts and driving impressions.....

I set out to get rid of all the pollution crap , have a simple small block in there that I didnt need a computer to tune. I was shooting for a small but decent performance gain , old school technology etc for about $1500. That I could open the hood at shows and be proud .

So I got rid of all the emissions garbage . Now in the future I can drop a potent small block in there that isnt hidden by all the piping , devices,pump etc..... .

I did primarily bolt ons , Headers ,MILD GMPP cam, intake ,carb, downstream exhaust I had done just after I bought the car...DYNOMAX super Turbo,3 inch int pipe., 2.5 tips.

So it starts great , idles too stock for my taste - no poppyness , no chop etc. 19 inches of vacuum . Doesnt even sound as radical as a 70's station wagon. The single biggest disappointment was this RAMJET camshaft ...while noticeably larger than the PEANUT CAM it really only adds mild power gains from say 2500-4800 then its flat . If you punch it from a roll it moans with the 2.73 and steadily climbs slow - due to the gear and heads is my guess - more the gears fault based on my experiences. It will not break them loose from say 25-30 mph roll (2.73) . You NEVER feel it get into any sort of power band ...just a slow steady climb all the way up.

Off idle snap is a little down from the TBI / peanut BUT I mean VERY minimally. The RAMJET cam however will burn the tires further once it breaks them loose off idle ...it takes it longer to regain traction.

Highway crusing if you nail it - it pulls a little harder than the TBI did....but again nothing eye opening.

My Butt Dyno says I have only 220 hp and MAYBE 280 TQ ..the motor had 170 stock. So at the end of the day I added maybe 50 HP . Dragstrip math says the car is only half a second quicker in the quarter after all this work. Hp gain estimates 15-20 headers ,10-15 intake,20-25 cam.

What would I do different ....

CAM I would have gone with the LT1 B car cam (more torque grind ) than F car LT1 cam OR the L98 cam with 1.6 RRS or the Comp Cams 258 ground on 112. I tried to save a little money using the GMPP RAMJET cam and based its projected performance in the 305 on the 383 hi torque Gm crate motor and the 350 hp hi torque crate motor ...it didnt work out that way in the 305.

Looking back I could have saved money by going mechanical fuel pump pulling through the stock fuel pump with its fuse removed. Some guys have said you can run-pull fuel that way - through the "dead" electric pump. Then you do away with the regulator , oil pressure switch fiasco,computer running the fuel pump show etc......much simpler setup - mechanical pump.

This is my hobby I enjoyed this build, reconfiguring it all ....but I have to admit I am disappointed by this 305 build and its performance gains - my first 305 and LAST 305 lol .

To save face I still may throw a 4:10 in it - to wake it up and make it snappy....if I do I will come back here and tell you all if it was the missing link to making this motor combo work as I expected it to .

86LG4Bird

iTrader: (1)

I wouldn't be second-guessing yourself so bad on cam choice.
~50 hp added to that little motor with very limited head flow is not so shabby.
I have a feeling with more cam, you'd have paid more penalty down low and midrange for a miniscule gain at the top. Like was said a long way back in this thread, more gearing and a good TC are really required to make use of more cam. With your gearing and converter, no cam on earth is going to give you that low end punch that you say it lacks.
Trust me, that cam is not limiting you. If your timing and fuel is optimized (are you sure your secondaries are opening!?), then the heads are limiting you right now in upper rpm power. With Vortec heads and tuned properly, you'd be over 250 rwhp with the Ramjet cam, given your exhaust and intake.
Oh, and don't think the B-car LT1 cam would have worked any better. You'd never see a difference.

jwfirebird

iTrader: (2)

the lumpy idle comes from tuning. you have to set the idle screws for best vacuum, set your timing about 18-20 then turn the idle stop screw out as low as it will go with your electrical loads on and not stall.

sootie007

Bird, yes secondaries are opening I confirmed doing the loose tie wrap trick awhile ago. I am tuned optimally - it has nothing left in it trust me . Bird writes -"Oh, and don't think the B-car LT1 cam would have worked any better. You'd never see a difference." I will defer to your experience and agree -probably not. Yes vortecs would definitely have to help breathing and torque here - there would probably be 15 -30 hp there with that swap which would put me at 250 and maybe what 20 lbs ish more torque.

JW I understand how you can make it sound a little different with tuning. Im running 30 locked right now which feels the absolute best of all the different timing setups I tried. So as you know 30 is going to smooth out any slight choppiness this cam has at idle. Even when I ran 8-10, 14-16 initial and functioning mechanical advance and had it idling in the weeds it still had no rumpety rump, chop -laaaazy sounding. Its just a wheezey smooth grind IMO at the end of the day. What cam is that idling in your video ?

Fast355

iTrader: (2)

Not trying to be rude, but what else do you expect from a TINY Marine cam that is designed to make power under 5K and not pull water back into the engine from the wet marine manifolds. I have a 215/220* @ .050 cam in my Express and it sounds STOCK at 700 rpm with 30* idle advance.

86LG4Bird

iTrader: (1)

more like 30-50 hp
I'm assuming your L03 heads are stock/unported.?

sootie007

Didn't take it as rude...expected something sounding along these lines ...ramjet 350 crate which has this exact same cam in it .....figured being a 305 it would have a little more rump than this 350 in the video .

sootie007

Y stockers.....I heard vortecs are worth that much on 350's but this is a 305 plus loss of compression etc so .......

86LG4Bird

iTrader: (1)

I wasn't suggesting you swap heads, just trying to emphasize your heads are the choke, and your cam choice isn't a very big hill of beans

Fast355

iTrader: (2)

Dual vs Single exhaust will definately add to the rumble. The Ramjet also has 1.6:1 full roller rockers which will make the cam seem a little bigger at the valve.

Fast355

iTrader: (2)

Honestly in a Ramjet 350 in the same car as yours really doesn't sound much healthier than your car.

sootie007

Fast - you are right, near exactly the same sound and he even has the louder Flowmaster"s" single chamber ...I have a quieter single Dynomax super turbo crossflow in mine....amazing how that 65 sounds healthier than the pair of these cars with the same cam and in one instance the same exact engine. That 65 has 3 inch pipes too I think -that could account for some difference in sound .Wasn't aware of 1.6 to 1.5 difference. However I know we are splitting hairs here but the 305 has 9.3 and the gmpp crate has 9.0 if I recall. So we are talking .029 more intake lift and .029 more exhaust lift with no noticeable idle sound change - interesting.

Bird you are correct - no hill there for sure.... just a pimple of a cam. Im sticking with my original impression this cam SUCKS lol.

Fast355

iTrader: (2)

Fairly certain the Ramjet is just a Marine 350 with a different intake and 1.6:1 roller rockers. The Marine 350 is advertised at 9.4:1.

http://gmpowertrain.com/pdfpage.aspx#M_57LV8_specs

sootie007

http://www.chevrolet.com/performance...m-jet-350.html

Chevrolet says 9:1 - who knows

"RAM JET 350 TECH SPECS
Part Number:
12499120 Engine Type:
Chevy Small-Block V-8
Displacement (cu. in.):350
Bore x Stroke (in.): 4.000 x 3.480
BlockCast-iron with two-bolt main caps
Crankshaft (P/N 10243068):Cast-iron
Connecting Rods (P/N 10108688 ):Powdered metal steel
Pistons (P/N 12571703):
Hypereutectic aluminum
Camshaft Type (P/N 14097395):
Hydraulic roller
Camshaft Lift (in.): .460 intake / .481 exhaust
Camshaft Duration (@.050 in.): 196° intake / 206° exhaust
Cylinder Heads (P/N 12528913):Vortec iron; 64-cc chambers
Valve Size (in.):1.940 intake / 1.500 exhaust
Compression Ratio:9.1 nominal
Rocker Arms (P/N 12367346):Aluminum roller style Rocker Arm Ratio:1.6
Recommended Fuel:92 octane
Ignition Timing:Base 10° BTDC, 32° Total




Maximum Recommended rpm:


5500




Balanced:


External

Fast355

iTrader: (2)

Whats even funnier is they contradict themself in the text just above the specifications.

sootie007

Lol...maybe it depends on what kind of day the builder is having lol.....

sootie007

I told you guys I may throw a gear at it ...well I bit the bullet and bought a 4.10 and posi for it. Today I drove it 26 miles the longest trip so far and it ran great all the way and at 160 degrees. I then parked in my buddys driveway. He is a GM line mechanic and is going to install it for me.

So after about 20 mins sitting talking about the swap with him I tried to start it and it immediately started but idled like absolute crap to the point of dying a few times. I then started it and revd it to 1500 for like 15 seconds and it cleared things out and it ran fine as I pulled it up into his garage onto his lift etc....

So this sounds like the old fuel or carb heat soak issue so many have and someone warned me about during this thread. I even made all my braided stainless lines longer on purpose to help dissipate any heat in the lines. My carb has a 3/8th spongey rubber type base gasket so I don't think the heat is getting into the fuel from the intake .......any suggestions ? When I get the car back from him in a week I will be troubleshooting this issue next (heat soak - percolation ?) .....its always something .

KILLemALL

iTrader: (3)

It is always something!
I am stoked to hear about your experience with your new gears.

jwfirebird

iTrader: (2)

4.10's are too steep for a 26in tire, i wish i went with 3.73. i run out of rpm at the track. i got them when i ran 1/8th but i moved and the local is 1/4 now. and its impossible to hook up with street tires on the street. what trans do you have?

i have a big cam but i was just pointing out it wouldnt be near as lumpy at idle if i had the timing so high and the rpm up

sootie007

JW I have the 700R .....I went 4:10 because I have run 3:73;s before with a 700r I liked it but you always want more.....if its ridiculous (when I put a real engine in here in a few years ) I can always run a taller tire to compensate,,,with this "radical" 305 at 220 HP I am not headed to the track anytime soon lol......

Ps I never understood why these 7.5's got a reputation for breaking....when I lifted the Richmond gear set box off my front porch when I received it from UPS I about hit myself in the head with the box it was so light compared to 12 bolt gears I have dealt with in the past. This ring gear is damx near the size of an oversized Crueller Donut LOL...no wonder they break.

KILLemALL

iTrader: (3)

An extra 100-150(or more) horsepower will be nice when you can get it in there,but I bet the fun factor is about to go way up