Help me smooth out and update my motor
05-06-2018, 07:46 PM
#1
Race Director
Thread Starter
Help me smooth out and update my motor
It seems like only yesterday that I blew up my stroker and replaced it with a cheap, throw away 350 that I picked up on Craigslist to keep the car on the road while I built a real motor. I didn’t pay much for it and sold the attached accessories for more than I paid for the whole thing. Perfect!
Fast forward more than 5 years and three moves, two back and forth across the country, and that throw away 350 is still in there. I know little specific about it but here’s what I know. It’s a Mexico built crate engine. CR unknown. The P.O. put an “RV” cam in it as well as a noisy gear drive. When I replaced the oil pan, it was very clean inside. 2 bolt mains.
The issue is that the cam is ridiculous. Idles like a top fuel dragster. Even more annoying is the acrid fuel fumes on idle. It’s also ridiculously cold blooded. Murder to keep it running until it warms up. Once past that, it actually runs pretty well, especially at RPMs.
It’s now getting to be summer here in Phoenix which means I probably won’t get to the new motor until after Thanksgiving. I also have a fall coastal run planned. I’m considering replacing the cam and timing set. Problem is getting an appropriate cam without having any idea of what’s in it. I could be convinced to pull and/or replace the heads......
Opinions? Please help me spend some money
Fast forward more than 5 years and three moves, two back and forth across the country, and that throw away 350 is still in there. I know little specific about it but here’s what I know. It’s a Mexico built crate engine. CR unknown. The P.O. put an “RV” cam in it as well as a noisy gear drive. When I replaced the oil pan, it was very clean inside. 2 bolt mains.
The issue is that the cam is ridiculous. Idles like a top fuel dragster. Even more annoying is the acrid fuel fumes on idle. It’s also ridiculously cold blooded. Murder to keep it running until it warms up. Once past that, it actually runs pretty well, especially at RPMs.
It’s now getting to be summer here in Phoenix which means I probably won’t get to the new motor until after Thanksgiving. I also have a fall coastal run planned. I’m considering replacing the cam and timing set. Problem is getting an appropriate cam without having any idea of what’s in it. I could be convinced to pull and/or replace the heads......
Opinions? Please help me spend some money
05-06-2018, 08:54 PM
#2
First off, what is the timing curve, and does it have a vacuum advance?
05-06-2018, 09:49 PM
#4
What type of carb? Just sounds like a good carb rebuild could solve most of the issues.
05-06-2018, 09:54 PM
#5
Le Mans Master
can you pull the valve covers off and get a number or some idea what heads you have .Then look for a cam that fits with your needs .what hp you want at what rpm.
05-06-2018, 10:34 PM
#6
Exploratory surgery is appropriate. Find out just what you have.
05-06-2018, 10:36 PM
#7
WARNING!!! Possible posts about rip it out and tear it apart is coming your way.
05-06-2018, 11:00 PM
#8
Race Director
Thread Starter
Originally Posted by Big2Bird;1597y146790
What type of carb? Just sounds like a good carb rebuild could solve most of the issues.
05-06-2018, 11:02 PM
#9
Race Director
Thread Starter
I'll be back next weekend and will pull the covers. I'll search my pics too as I think I took s few before.
Trying to avoiding going down this path. If I'm going to invest that kind of effort, might as well finish the other motor.
Trying to avoiding going down this path. If I'm going to invest that kind of effort, might as well finish the other motor.
05-06-2018, 11:24 PM
#10
Race Director
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"RV" cam and "idles like a Top Fueler" sound like two extreme opposites.
RV cams run like smooth butter......did you get any paperwork with what he put in it??
JIM
RV cams run like smooth butter......did you get any paperwork with what he put in it??
JIM
05-07-2018, 02:56 AM
#11
Race Director
Thread Starter
Nothing at all came with it. Extremely lopey idle and (I’m presuming) a ton of overlap. Never measured the lift but it can’t be too much on those stock, smog heads.
05-07-2018, 05:58 AM
#12
Safety Car
Sounds like a carb ptoblem, too lean while warming up. Is the choke working correctly? Are the idle mixture screws adjusted correctly? Is base timing with no vacuum in the 15 degree range?
05-07-2018, 08:36 AM
#13
Drifting
Sounds like you are going to have to start wrenching. Have you checked to see if the cam timing is off by a tooth? Check condition of plug wires and dizzy cap.
05-07-2018, 01:15 PM
#15
Race Director
Get a timing tape and a harbor freight vise grip base dial indicator. You will get your lift and all timing points. But it sounds like he thought RV stood for race vehicle.
05-07-2018, 06:07 PM
#17
Melting Slicks
The carb should run fine on another smallblock. Are you sure the float's not stuck after all the moving across the country while it's not been running?
05-07-2018, 07:15 PM
#18
Le Mans Master
I would start with measuring your vacuum level and what your timing specs are.
Too little vacuum and your vacuum advance drops out at idle and the carb will not run right unless you give it more idle bypass air.
Too little vacuum and your vacuum advance drops out at idle and the carb will not run right unless you give it more idle bypass air.
05-13-2018, 01:24 PM
#20
Race Director
Thread Starter
Pulled some codes off the block and head today.
Block: 3970010
Heads: 187
GM 12
83417369
Made in Mexico
Only took 1 pic but can get anything additional that would help. I did notice that the covers needed cleaning and polishing so that should increase the HP a little.
Block: 3970010
Heads: 187
GM 12
83417369
Made in Mexico
Only took 1 pic but can get anything additional that would help. I did notice that the covers needed cleaning and polishing so that should increase the HP a little.
Last edited by CA-Legal-Vette; 05-13-2018 at 02:36 PM.