El Camino Central Forum banner

1 - 20 of 23 Posts

·
Registered
Joined
·
196 Posts
Discussion Starter #1
I was wondering if anyone on the list has, or knows of anyone who has, installed a 350/290 crate motor in their EC, using the ECM and CC Quadrajet etc? If so, I would like to compare notes on how theirs runs and any problems they had.

Jim
 

·
Registered
Joined
·
775 Posts
A mild build 350 is going in my 84 Elky right now with the original quadrajet. I will let you know how it turns out.
RTT:nanawrench:
 

·
Registered
Joined
·
2,102 Posts
are you still haveing issues ?. i ran a flat top piston,vortec headed motor for a couple months with all of my emission stuff except for the egr and had no problems.i was however useing a 5.7 chip,est module and knock sensor
 

·
Registered
Joined
·
196 Posts
Discussion Starter #4
are you still haveing issues ?. i ran a flat top piston,vortec headed motor for a couple months with all of my emission stuff except for the egr and had no problems.i was however useing a 5.7 chip,est module and knock sensor
Still having problems with it. I'm taking it to the Chevrolet Dealership in the area that sells GM Performance Parts tomorrow. I want them to check the compression on it.
I had about a week right after the headers were installed when it ran fairly smooth. Then it started missing and I thought it was the spark plug wires because the mechanic hadn't gotten the new wires and protective boot covers on. Got new wires and boot covers, still had the miss under light load. Mechanic thought it was the 305 Carb, so I got a rebuilt 350 Carb., still missing.
Since it ran fairly smooth for that week (not great, but fairly smooth), I think something in the motor has failed, but I don't know. The mechanics that have worked on the motor so far don't think its the motor itself, I want to know for sure.

I have gotten three ideas on this situation:

#1. Some people are saying that this motor should run fine with the CC Quadrajet, stock distributor, and ECM. (this includes three distuators of GM crate motors)
#2. Some are saying the cam and the computor are fighting each other and it will never run correctly until I install a non computer carb and non computer distributor.
#3. One guy I spoke to recently at GM Tech Support said the 350/290 is really not good for computor controlled vechicles because of the cam. He said that some are having good results swapping out the 290 cam with the cam for the 350/330 HO crate motor. He said if I went this route, I would still have the 24 month, 50,000 mile warrenty on the motor unless it was a cam related problem. The 330 HO cam has more overlap than the cam in the 290.

Perhaps we will find something out tomorrow.

Jim
 

·
ZERO MPG
Joined
·
15,367 Posts
Still having problems with it. I'm taking it to the Chevrolet Dealership in the area that sells GM Performance Parts tomorrow. I want them to check the compression on it.
I had about a week right after the headers were installed when it ran fairly smooth. Then it started missing and I thought it was the spark plug wires because the mechanic hadn't gotten the new wires and protective boot covers on. Got new wires and boot covers, still had the miss under light load. Mechanic thought it was the 305 Carb, so I got a rebuilt 350 Carb., still missing.
Since it ran fairly smooth for that week (not great, but fairly smooth), I think something in the motor has failed, but I don't know. The mechanics that have worked on the motor so far don't think its the motor itself, I want to know for sure.

I have gotten three ideas on this situation:

#1. Some people are saying that this motor should run fine with the CC Quadrajet, stock distributor, and ECM. (this includes three distuators of GM crate motors)
#2. Some are saying the cam and the computor are fighting each other and it will never run correctly until I install a non computer carb and non computer distributor.
#3. One guy I spoke to recently at GM Tech Support said the 350/290 is really not good for computor controlled vechicles because of the cam. He said that some are having good results swapping out the 290 cam with the cam for the 350/330 HO crate motor. He said if I went this route, I would still have the 24 month, 50,000 mile warrenty on the motor unless it was a cam related problem. The 330 HO cam has more overlap than the cam in the 290.

Perhaps we will find something out tomorrow.

Jim

Jim I hope you don't mind me jumping in with you my motor is coming and I need all the info myself CCC has already got me going in the right direction on a couple issues with a 305/350 swap and the ECM chip. If anyone has had problems that have been resolved I'm sure both of us could use the knowledge .
Thanks
Robert
 

·
Registered
Joined
·
12,533 Posts
x2 on the knock sensor on an overall running problem.. check the timming then unplug it and check it..:dontknow:
how is the overall driveability and gas milage??

for finding a miss pull each plug wire while watching a vacuum gauge,,
even try your timming light on each plug wire watching the vac gauge to narrow it down..
keep the #5 and 7 plug wires seperated..:texas:
 

·
Registered
Joined
·
196 Posts
Discussion Starter #8
Just got home from the Chevrolet Dealership that originally sold the crate motor to the installer. They say compression is low on all cyclinders (averaging about 90 psi). They don't know why yet so I have to take it back next week and let them keep it for a few days.
So the story is to be continued...

Jim
 

·
Venerated Member RIP
Joined
·
2,918 Posts
Any updates? I used this same 350/290hp in a non-ecm elky - old 66. Having very low idle, if I boost up the idle setting, then in Park I'm idling at 1200 or even more....

I need a different torque converter with a higher stall.... but in researching this issue, my carb guy found this info/link....

http://www.nastyz28.com/forum/archive/index.php/t-138635.html

It concerns a CAM MISMATCH by GM... old style cam, low compression ratio, etc etc

Also had TCI 741500 torque converter recommended for my powerglide / 350 combo.
 

·
Registered
Joined
·
196 Posts
Discussion Starter #10
Any updates? I used this same 350/290hp in a non-ecm elky - old 66. Having very low idle, if I boost up the idle setting, then in Park I'm idling at 1200 or even more....

I need a different torque converter with a higher stall.... but in researching this issue, my carb guy found this info/link....

http://www.nastyz28.com/forum/archive/index.php/t-138635.html

It concerns a CAM MISMATCH by GM... old style cam, low compression ratio, etc etc

Also had TCI 741500 torque converter recommended for my powerglide / 350 combo.
The dealership never found out why the motor has low compression, but they have agreed to replace it. When I was talking to GM Tech. Support about the problems with the motor they said that people have put the cam from the 350 330 hp HO motor in the 350 290 and been pleased with the results. They said it work better with my ECM, EGR, etc. They also said it would lower the torque and hp curves and generally be a better running engine.
The dealership has agreed to make this change to the replacement motor for the price of the cam plus two hours labor. Tech. Support said this motor should be about 300hp with the new cam. There is no date set when I'm going to get it back so I'm just keeping my fingers crossed.

Jim
 

·
Deputy Director, Region 1
Joined
·
2,566 Posts
I put this engine in my 78 back in Nov 2010. I have an edelbrock AVS 650 cfm and performer manifold. Rebuilt TH350 and not sure what rear. It's not a posi and is probably like 2:? Have P235/60 TA's so that probably changes the ratio. But the car has plenty of power and low end torque. Gets crappy MPG's though. Best I can do is 10-12 city and maybe13-15 Hwy unless I'm not climbing hills allday.
 

·
Registered
Joined
·
2,039 Posts
Any updates? I used this same 350/290hp in a non-ecm elky - old 66. Having very low idle, if I boost up the idle setting, then in Park I'm idling at 1200 or even more....

I need a different torque converter with a higher stall.... but in researching this issue, my carb guy found this info/link....

http://www.nastyz28.com/forum/archive/index.php/t-138635.html

It concerns a CAM MISMATCH by GM... old style cam, low compression ratio, etc etc

Also had TCI 741500 torque converter recommended for my powerglide / 350 combo.
If the cam in that motor is indeed the old L-82 cam and is running low compression then your idle experience isnt far off especially if you have a tight convertor, for example my L-82 equipped corvette with that cam was fairly doggy in the bottom end until you got into the RPM's to where it made power.

The vette motor had over 9:1 CR and 3.70:1 rear gears, which your 66 likely doesnt. The factory idle settings for a L-82 vette....900/N 700/D
 

·
Registered
Joined
·
23 Posts
Here is my opinion. Nobody makes a good plug-in PROM to make your application work to your satisfaction. There is not that much difference between the cam in the 290 HP 350 crate motor and the 350 (Vortec) HO motor. They both will want to idle at about 1000-1200 RPM in neutral. As for my El Camino, I bought it in 1992 with 78000 (approx) miles. It now has 191,000 approx. miles, on the chassis with the following mods:

350 HO (GMPP crate motor), installed in 2000 when car had 141000 miles with GMPP Q-Jet manifold.
200R4 Art Carr trans with 2800 RPM stall convertor.
Edelbrock TES headers
3.00" exhaust past high-flow cat convertor
Sean Murphy E-QJet
Double snorkle GM induction (for ZZ4 Camaro LG4 conversion)
3.73 posi from '87 Monte SS
Hypertech chip (for 1987 police car Caprice)
All (front and rear) suspension rebuilt with polygraphite bushings
350 knock sensor+all other GM pieces for ZZ4-to Camaro LG4 smog-legal conversion
new 3 row radiator (replacing leaky replacement 3-row radiator)
15X7 Centerline Wheels
225R1570 Goodyear GSA radials

Every thing has worked to suffice on the road, BUT it has never performed to my expectations for this motor/trans combination. It runs Okay under normal use and gets adequate MPG (16-20) as a daily driver, but the performance is just not there...under full throttle it is just uninspiring. I know this motor should make for more fun, since it should be making double the horsepower of the stock engine. I am not convinced that my PROM is good for this combination, or that anyone is up to speed to produce one which will work convincingly. Does anyone have suggestions for a PROM which will make this combination come alive? It works, but does not make the heart race.
BTW, I am recently retired, so my heart maybe should not be racing TOO much...but that is what we all live for, I believe.:twisted:
 

·
Registered
Joined
·
196 Posts
Discussion Starter #14
Here is my opinion. Nobody makes a good plug-in PROM to make your application work to your satisfaction. There is not that much difference between the cam in the 290 HP 350 crate motor and the 350 (Vortec) HO motor. They both will want to idle at about 1000-1200 RPM in neutral. As for my El Camino, I bought it in 1992 with 78000 (approx) miles. It now has 191,000 approx. miles, on the chassis with the following mods:

350 HO (GMPP crate motor), installed in 2000 when car had 141000 miles with GMPP Q-Jet manifold.
200R4 Art Carr trans with 2800 RPM stall convertor.
Edelbrock TES headers
3.00" exhaust past high-flow cat convertor
Sean Murphy E-QJet
Double snorkle GM induction (for ZZ4 Camaro LG4 conversion)
3.73 posi from '87 Monte SS
Hypertech chip (for 1987 police car Caprice)
All (front and rear) suspension rebuilt with polygraphite bushings
350 knock sensor+all other GM pieces for ZZ4-to Camaro LG4 smog-legal conversion
new 3 row radiator (replacing leaky replacement 3-row radiator)
15X7 Centerline Wheels
225R1570 Goodyear GSA radials

Every thing has worked to suffice on the road, BUT it has never performed to my expectations for this motor/trans combination. It runs Okay under normal use and gets adequate MPG (16-20) as a daily driver, but the performance is just not there...under full throttle it is just uninspiring. I know this motor should make for more fun, since it should be making double the horsepower of the stock engine. I am not convinced that my PROM is good for this combination, or that anyone is up to speed to produce one which will work convincingly. Does anyone have suggestions for a PROM which will make this combination come alive? It works, but does not make the heart race.
BTW, I am recently retired, so my heart maybe should not be racing TOO much...but that is what we all live for, I believe.:twisted:
I've had some people tell me that the ECM's and the proms in these early computer controlled vehicles really doesn't do to much. That they only change the timing a couple of degrees. The latest person to tell me this was a distributor of GM Performance crate motors.
I'd love to hear how much they do control and how, and their effect on performance. I currently have the ECM and prom from a 87 Monte Carlo SS in my 87 EC.

Jim
 

·
Registered
Joined
·
196 Posts
Discussion Starter #15
Here is my opinion. Nobody makes a good plug-in PROM to make your application work to your satisfaction. There is not that much difference between the cam in the 290 HP 350 crate motor and the 350 (Vortec) HO motor. They both will want to idle at about 1000-1200 RPM in neutral. As for my El Camino, I bought it in 1992 with 78000 (approx) miles. It now has 191,000 approx. miles, on the chassis with the following mods:

350 HO (GMPP crate motor), installed in 2000 when car had 141000 miles with GMPP Q-Jet manifold.
200R4 Art Carr trans with 2800 RPM stall convertor.
Edelbrock TES headers
3.00" exhaust past high-flow cat convertor
Sean Murphy E-QJet
Double snorkle GM induction (for ZZ4 Camaro LG4 conversion)
3.73 posi from '87 Monte SS
Hypertech chip (for 1987 police car Caprice)
All (front and rear) suspension rebuilt with polygraphite bushings
350 knock sensor+all other GM pieces for ZZ4-to Camaro LG4 smog-legal conversion
new 3 row radiator (replacing leaky replacement 3-row radiator)
15X7 Centerline Wheels
225R1570 Goodyear GSA radials

Every thing has worked to suffice on the road, BUT it has never performed to my expectations for this motor/trans combination. It runs Okay under normal use and gets adequate MPG (16-20) as a daily driver, but the performance is just not there...under full throttle it is just uninspiring. I know this motor should make for more fun, since it should be making double the horsepower of the stock engine. I am not convinced that my PROM is good for this combination, or that anyone is up to speed to produce one which will work convincingly. Does anyone have suggestions for a PROM which will make this combination come alive? It works, but does not make the heart race.
BTW, I am recently retired, so my heart maybe should not be racing TOO much...but that is what we all live for, I believe.:twisted:
How did you handle the EGR with that motor?

Jim
 

·
Registered
Joined
·
23 Posts
All factory emission controls are hooked up and functional. The heat riser was eliminated by the header system. The intake manifold has external provision for EGR input, since these Vortec heads do not have exhaust crossover under the carburator. I routed exhaust gas from the driver's side header where the AIR system normally is plumbed, so the AIR pump is only plumbed to the pass. side header and catalytic convertor.

Steve
 

·
ZERO MPG
Joined
·
15,367 Posts
#6
05-27-2012, 03:36 PM

Here's an article that my help but this is the same as I'm doing 350/260hp.
Robert


350 build
I found this article in Chevy High Performance Magazine. It is written by Kevin McClelland. I would do this. I throughly believe in his advice.​

Simple Crate

I have a daily driver ’87 El Camino with a tired 305. I’d like to put a crate 350 in it. Nothing radical, just a stocker with maybe 200-250 hp. It also must pass California smog. I remember reading an article (four to five years ago) about a crate motor with an Edelbrock manifold, carb, and a 305 cam, but I no longer have the magazine. Any suggestions? Thanks,
Doug Cole
Via email
Doug, for a simple crate 350 engine swap we recommend going with a factory GM Goodwrench crate engine. GM has been offering this engine forever. They were originally called the Target Master Crate engine and were renamed when GM started branding itself Goodwrench. GM has built millions of these engines over the years, and we’ve used them for truck and passenger car replacement engines, and whipped them on the dyno for run after run, without even a whimper. Give our good friend Ken Casey a call at the new John Elway Chevrolet (800.345.5744) for pricing and freight for a 350 Goodwrench engine (PN 10067353). This is a direct replacement engine for ’71-85 applications. This will drop right into your ’Elco and all you’ll need to pick up is a standard-balance 153-tooth flexplate (PN 471529). Yes, you will need to truck the engine out from Colorado, but Casey is very competitive with his pricing, we’re guessing under $2,000 for a brand-new engine. All this and a factory warranty on the engine for two years and 50,000 miles!
As you said, you had a story of a crate with a simple camshaft swap and manifold. We’d go with an Edelbrock Performer EGR manifold (PN 3701), and the matching camshaft (PN 3702). This camshaft shaft specs out at 194/214 duration at 0.050-inch tappet lift, 0.396/0.442-inch max lift, and is ground on 112 centers. You will notice that this is a very short camshaft. It was originally developed back in 1985 to work in the LG4 305s, which were computer controlled. Oh yeah, that’s the engine that’s in your ’Elco. This camshaft will work in concert with your factory computer calibration and pass emissions in the state of California. The short nature of this camshaft will produce great throttle response and make outstanding slow-speed torque. The engine will make strong power to 5,000 rpm and produce about 250 hp through the stock exhaust manifolds and cat.
If you wish to step up to headers, you could also add the Edelbrock TES system, which is emissions legal in California and will boost your peak horsepower on this package by around 20 hp. The TES system for your LG4 305-equipped El Camino is PN 68783. This kit will bolt right in to your El Camino’s factory 21/4-inch catalytic converter. If you wish to step up the exhaust to the high-flow Corvette four-bolt–style converter, go with PN 68793. This, in conjunction with a nice after-cat exhaust, will round out your emissions-legal engine swap nicely.
We know this engine won’t turn the world with its sheer power, but it will give you a great daily driver that will get decent gas mileage and produce over 100 hp more than the stock 305! This will make a big difference in the fun factory with your ’Elco. Good luck! CHP
Sources: edelbrock.com, elwaydealers.com
:yell:​


 

·
Registered
Joined
·
196 Posts
Discussion Starter #18
Here is my opinion. Nobody makes a good plug-in PROM to make your application work to your satisfaction. There is not that much difference between the cam in the 290 HP 350 crate motor and the 350 (Vortec) HO motor. They both will want to idle at about 1000-1200 RPM in neutral. As for my El Camino, I bought it in 1992 with 78000 (approx) miles. It now has 191,000 approx. miles, on the chassis with the following mods:

350 HO (GMPP crate motor), installed in 2000 when car had 141000 miles with GMPP Q-Jet manifold.
200R4 Art Carr trans with 2800 RPM stall convertor.
Edelbrock TES headers
3.00" exhaust past high-flow cat convertor
Sean Murphy E-QJet
Double snorkle GM induction (for ZZ4 Camaro LG4 conversion)
3.73 posi from '87 Monte SS
Hypertech chip (for 1987 police car Caprice)
All (front and rear) suspension rebuilt with polygraphite bushings
350 knock sensor+all other GM pieces for ZZ4-to Camaro LG4 smog-legal conversion
new 3 row radiator (replacing leaky replacement 3-row radiator)
15X7 Centerline Wheels
225R1570 Goodyear GSA radials

Every thing has worked to suffice on the road, BUT it has never performed to my expectations for this motor/trans combination. It runs Okay under normal use and gets adequate MPG (16-20) as a daily driver, but the performance is just not there...under full throttle it is just uninspiring. I know this motor should make for more fun, since it should be making double the horsepower of the stock engine. I am not convinced that my PROM is good for this combination, or that anyone is up to speed to produce one which will work convincingly. Does anyone have suggestions for a PROM which will make this combination come alive? It works, but does not make the heart race.
BTW, I am recently retired, so my heart maybe should not be racing TOO much...but that is what we all live for, I believe.:twisted:
Very nice, the prom from a Monte Carlo SS might be a better match (I hope it is, that's what I'm using in mine). The SS had the L69 motor and the cam in it is Lift .403L/.415E duration 202o I, 206o E, separation 114

The cam I'm going to be using (and I think is in yours also)is pn 24502476 Lift .435"I,.460"E Duration @.50 212 I, 222 E, separation 112.5

I'm also going to be using the Edelbrock 3701 intake.

I think GM should footnote these crate motors as having 15 to 25 percent less horsepower at the rear wheels than at the flywheel with no drive line friction or accessories attached. I'm just hoping to have the acceleration and towing capacity of my 235 hp Grand Cherokee.

Jim
 

·
Registered
Joined
·
23 Posts
The tech guy at Hypertech suggested the police Caprice PROM over the Monte Carlo SS one at the time because of the change from 305 to 350 CID. I didn't argue with him.

If I had it all to do over, I would probably ditch all of the PC plumbing stuff and put on long tube headers with X-pipe, true duals, a non-computer 750 CFM carb and conventional HEI distributor. I would be much closer to the rated HP for this engine. At the time, Oklahoma required that all factory PC equipment be intact and had yearly visual state inspections. Since then they have changed the law. Keeping the car "compliant" probably cost me an extra $1000 ten years ago for the special headers, hi-flo cat, electric spark control module, 350 knock sensor, etc., etc., etc.

On the plus side, this combination probably gets 4-5 MPG better gas mileage...maybe more. With that other stuff, I would probably have my foot in the throttle more often.

Steve
 

·
Registered
Joined
·
2,039 Posts
I think GM should footnote these crate motors as having 15 to 25 percent less horsepower at the rear wheels than at the flywheel with no drive line friction or accessories attached.
Jim
Its the same for cars, HP ratings have always been this way - at the flywheel - crate motors are rated gross as opposed to net, because there is no way GM can know what accessories or even driveline are going to be attached to the crate they are selling. Converting gross to rear wheel HP is more than 15 to 25% to be sure.
 
1 - 20 of 23 Posts
Top