Couple of Questions for ya. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

etg · 12-05-2010, 02:16 PM

Hello all, I'm working on a 69 C20 lwb fleet. It's got a rebuilt 350sbc with a 700r4, eddy carb, and a freshly fixed radiator. Today I am reinstalling the radiator, and trying to do some final maintenance before I get this thing on the road. I have a few questions if you don't mind helping me out, answering any of it is helpful.

1. Here is the radiator I just had soldered and flushed. There a little bit of debris rattling around inside, is this ok or will it potentially cause damage to the fins on the radiator? I fished some out, but not all. Secondly I noticed the transmission was hooked up to the radiator, is this a replacement for a transmission cooler, or am I supposed to add one as well? Are heating problems common for a 700r4?

2. I've heard some troubling things about the TV cable on my 700r4 being a common reason to burn it. This is what it looks like now, you can see my finger pointing to the brass adjust tab and the wire running to the throttle linkage. Any tips on what to look for or measure to make sure it's ok? I ran the truck for a little bit before I stopped to do some maintenance and it seemed fine, then I adjusted the cable by pushing the tab and pushing the plastic line shroud/grommet back into the bracket until the clicking stopped, which I read online but can't find the source again. Lastly on the 700r4, what is this lockup I hear about, how can I tell if I have it, and is it ok to run without out?

3. There is a blue wire running from somewhere under the dash (it's a mess down there) out to behind the distributer, it's marked 14gw Oil. What the heck does this connect to?

4. Lastly, there are 3 ports on the front of my my eddy performer 600cfm carb. One I know is the vacuum advance to the distributer, the one on the left that is hooked up. What are the other 2?

feel free to ask questions or leave comments. I'll get back to this thread after I'm done out there and my hands are clean enough to use my computer again

60ratrod · 12-05-2010, 04:50 PM

generally the larger of the 3 nipples on the front of the carb is used for the pcv valve, which if you don't have one you need to get one. and the ports on the radiator for the tranny lines are usually sufficient for stock-mild performance, anything more and you need an external oil cooler in addition to the one in the radiator. the blue wire sounds like it is for an electric oil pressure gauge, which the sensor normally is installed in the back of the block by the distributor, but it can be installed by either the timing cover on the front of the motor or down by the oil filter like on newer engines.

etg · 12-05-2010, 08:39 PM

Hey thanks Ratrod, that's helpful. Now to do some research on pcv and finding my oil sensor. Things got outta hand today with the radiator out, decided to paint the inner grill, vertical blade on the core support, hood latch spring thing, and the upper radiator supports. Tomorrow I'm going to fab a way keep the hood from opening with just the stock latch, I'm worried about looky loos.

etg · 12-05-2010, 09:02 PM

Nevermind the stuff in red doesn't make sense. The blowby goes into the crankcase, up to be released by the valve covers. Therefore that doohicky in the middle needs to be connected to the intake manifold's pcv outlet via a rubber hoes, I think. Fortunately what might be that outlet is blocked by my thermostat housing....

So from what I've read the pcv valve relieve pressure from the crankcase that is leaked by the piston rings. This causes a buildup which mixes the fuel into air and needs to be bled in order to keep leaks from occurring and oil going bad. If you look in the picture above of the carb, you can see that my passenger side valve cover has a cap, this cap has vent holes on the bottom and what seems like a filter. Does this accomplish the same thing as the pcv valve, it's just positioned elsewhere? If so, should I have one on each valve cover or is that one sufficient?

60ratrod · 12-05-2010, 10:41 PM

you can run it to the large nipple on the front of the carb with no issues. actually i think that's where the stock pcv valve attached on the q-jets. the only direct manifold vacuum port that needs to be there is the one for the power brakes on the vacuum power booster

etg · 12-06-2010, 04:36 AM

Quote:

Originally Posted by 60ratrod

you can run it to the large nipple on the front of the carb with no issues. actually i think that's where the stock pcv valve attached on the q-jets. the only direct manifold vacuum port that needs to be there is the one for the power brakes on the vacuum power booster

Got it. So I figure that cap visible in the picture on the passenger side is a breather cap. It has ventilation holes on the bottom of it. This feeds fresh air to the crankcase, then the pcv nipple on the carb sucks fueled air from the crankcase so it can burn it off. This pcv nipple on the carb runs to the pcv valve on the drivers side valve cover. Only problem in my case is that there is a simple rubber grommet/cap on the driver valve cover. Do I need to drill a new whole for the pcv valve? Or can I find a pcv valve that comes as a cap and just replace the static cap? Thanks again for the help, you learn somethin new everyday!

*mrhino* · 12-06-2010, 06:17 AM

You only need one pcv and one way to fill the engine with oil. if you drivers side has a rubber plug in it now. use that for your oil fill. Pick up a 710 cap form a late 80's Camaro, they push right into your existing hole in the valve cover . get rid of that stupid breather cap and put a pcv there. you can get new grommets at the parts store. all those breathers do is fill with oil and leak all over. The middle vacuum port goes to pcv, one goes to a vacuum advance, and the other would go to a modulator valve on the trans. ( 700r's dont have one)
Torque converter lock ups are inside the trans. Yes you should have one, it saves the life of the trans and would help with fuel economy.
The rattling in your rad. might be solder, what ever it is you should try to get out as much as you can.
You need a new detent cable (aka kickdown cable) yours appears to be broken, and someone has jerry rigged it. and you may not get the proper adjustment.
Yes the the blue wire sounds like its for oil pressure sender.
heat is the number one killer of transmissions. so hook up those lines to the radiator, you shouldn't need a seperate cooler unless your towing or something like that. and lastly, make your pictures a little smaller, no one likes to scroll back and forth to read a post..

12-05-2010, 02:16 PM	#1
etg Registered User Join Date: Apr 2006 Location: San Diego Posts: 147	Couple of Questions for ya. Hello all, I'm working on a 69 C20 lwb fleet. It's got a rebuilt 350sbc with a 700r4, eddy carb, and a freshly fixed radiator. Today I am reinstalling the radiator, and trying to do some final maintenance before I get this thing on the road. I have a few questions if you don't mind helping me out, answering any of it is helpful. 1. Here is the radiator I just had soldered and flushed. There a little bit of debris rattling around inside, is this ok or will it potentially cause damage to the fins on the radiator? I fished some out, but not all. Secondly I noticed the transmission was hooked up to the radiator, is this a replacement for a transmission cooler, or am I supposed to add one as well? Are heating problems common for a 700r4? 2. I've heard some troubling things about the TV cable on my 700r4 being a common reason to burn it. This is what it looks like now, you can see my finger pointing to the brass adjust tab and the wire running to the throttle linkage. Any tips on what to look for or measure to make sure it's ok? I ran the truck for a little bit before I stopped to do some maintenance and it seemed fine, then I adjusted the cable by pushing the tab and pushing the plastic line shroud/grommet back into the bracket until the clicking stopped, which I read online but can't find the source again. Lastly on the 700r4, what is this lockup I hear about, how can I tell if I have it, and is it ok to run without out? 3. There is a blue wire running from somewhere under the dash (it's a mess down there) out to behind the distributer, it's marked 14gw Oil. What the heck does this connect to? 4. Lastly, there are 3 ports on the front of my my eddy performer 600cfm carb. One I know is the vacuum advance to the distributer, the one on the left that is hooked up. What are the other 2? feel free to ask questions or leave comments. I'll get back to this thread after I'm done out there and my hands are clean enough to use my computer again Last edited by etg; 12-05-2010 at 02:31 PM.

12-05-2010, 04:50 PM	#2
60ratrod yes, i do Join Date: Jun 2007 Location: Spokane, wa Posts: 2,734	Re: Couple of Questions for ya. generally the larger of the 3 nipples on the front of the carb is used for the pcv valve, which if you don't have one you need to get one. and the ports on the radiator for the tranny lines are usually sufficient for stock-mild performance, anything more and you need an external oil cooler in addition to the one in the radiator. the blue wire sounds like it is for an electric oil pressure gauge, which the sensor normally is installed in the back of the block by the distributor, but it can be installed by either the timing cover on the front of the motor or down by the oil filter like on newer engines. __________________ ERROR 404....... SNAPPY COMEBACK NOT FOUND _______________________________________________________________________________________________ -60 Chevy C10, dead 350/good th350 combo, sitting on a 76 c10 blazer frame, built from 11 different vehicles "the abomination" -07 gmt900 silverado 1500 lt xcab z71, granite blue -81 suzuki gs650g "shelah"- current project -81 kz1000m1 csr "sarge" -next project (just beautification) -07 kawasaki vulcan classic vn900

12-05-2010, 08:39 PM	#3
etg Registered User Join Date: Apr 2006 Location: San Diego Posts: 147	Re: Couple of Questions for ya. Hey thanks Ratrod, that's helpful. Now to do some research on pcv and finding my oil sensor. Things got outta hand today with the radiator out, decided to paint the inner grill, vertical blade on the core support, hood latch spring thing, and the upper radiator supports. Tomorrow I'm going to fab a way keep the hood from opening with just the stock latch, I'm worried about looky loos.

12-05-2010, 09:02 PM	#4
etg Registered User Join Date: Apr 2006 Location: San Diego Posts: 147	Re: Couple of Questions for ya. Nevermind the stuff in red doesn't make sense. The blowby goes into the crankcase, up to be released by the valve covers. Therefore that doohicky in the middle needs to be connected to the intake manifold's pcv outlet via a rubber hoes, I think. Fortunately what might be that outlet is blocked by my thermostat housing.... So from what I've read the pcv valve relieve pressure from the crankcase that is leaked by the piston rings. This causes a buildup which mixes the fuel into air and needs to be bled in order to keep leaks from occurring and oil going bad. If you look in the picture above of the carb, you can see that my passenger side valve cover has a cap, this cap has vent holes on the bottom and what seems like a filter. Does this accomplish the same thing as the pcv valve, it's just positioned elsewhere? If so, should I have one on each valve cover or is that one sufficient? Last edited by etg; 12-05-2010 at 09:21 PM.

12-05-2010, 10:41 PM	#5
60ratrod yes, i do Join Date: Jun 2007 Location: Spokane, wa Posts: 2,734	Re: Couple of Questions for ya. you can run it to the large nipple on the front of the carb with no issues. actually i think that's where the stock pcv valve attached on the q-jets. the only direct manifold vacuum port that needs to be there is the one for the power brakes on the vacuum power booster __________________ ERROR 404....... SNAPPY COMEBACK NOT FOUND _______________________________________________________________________________________________ -60 Chevy C10, dead 350/good th350 combo, sitting on a 76 c10 blazer frame, built from 11 different vehicles "the abomination" -07 gmt900 silverado 1500 lt xcab z71, granite blue -81 suzuki gs650g "shelah"- current project -81 kz1000m1 csr "sarge" -next project (just beautification) -07 kawasaki vulcan classic vn900

12-06-2010, 06:17 AM	#7
mrhino Account Suspended Join Date: Aug 2007 Location: USA Posts: 1,223	Re: Couple of Questions for ya. You only need one pcv and one way to fill the engine with oil. if you drivers side has a rubber plug in it now. use that for your oil fill. Pick up a 710 cap form a late 80's Camaro, they push right into your existing hole in the valve cover . get rid of that stupid breather cap and put a pcv there. you can get new grommets at the parts store. all those breathers do is fill with oil and leak all over. The middle vacuum port goes to pcv, one goes to a vacuum advance, and the other would go to a modulator valve on the trans. ( 700r's dont have one) Torque converter lock ups are inside the trans. Yes you should have one, it saves the life of the trans and would help with fuel economy. The rattling in your rad. might be solder, what ever it is you should try to get out as much as you can. You need a new detent cable (aka kickdown cable) yours appears to be broken, and someone has jerry rigged it. and you may not get the proper adjustment. Yes the the blue wire sounds like its for oil pressure sender. heat is the number one killer of transmissions. so hook up those lines to the radiator, you shouldn't need a seperate cooler unless your towing or something like that. and lastly, make your pictures a little smaller, no one likes to scroll back and forth to read a post..



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.