engine troubles

[4WDKC]

I'm still in the process of learning but I didn't know it was possible to get a set of vortec heads for a pre 86 350.

not from the factory but, the 96-99 vortec heads bolt on and only require a different intake manifold to mathc their ports and bolt pattern you can use stock rockers from a 96-98 chevy truck.

 

[78C10BigTen]

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Here you go. Might be kind of tough to hear, But it was louder in the cab plus I was driving about 55-70 here so there is some wind and road noise. Its the rattling towards the beginning of the video. The louder at the end I think is my keys.

Also even if it is a fuel issue, Its still a good idea to get a set of matching heads.

That exact sound my father used to call "spark knock" a lil timing tweak and better gas made it go away.

 

[Dutch Rutter]

That exact sound my father used to call "spark knock" a lil timing tweak and better gas made it go away.

Pretty much. On a smaller motor like say a 250cc two stroke atv motor running this way, it will eventually melt the piston. I know this from experience.
On a car or truck motor it can result in a valve being pulled up into the head, Very uncommon from what I was told when I did it with the 3.slow in my old Ferd ranger. This happened because of running a tuner in eco mode and driving it like a race truck while pulling a trailer up hills. Basically the same idea, starving it of gas while in higher RPM.

If one still wanted to run regular pump gas I bet they could retard (for lack of better words) their timing and it would go away.

Note to OP: Would also be a good idea to put a timing light on it and make sure everything is good there.

 

[Michael Nielsen]

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Here you go. Might be kind of tough to hear, But it was louder in the cab plus I was driving about 55-70 here so there is some wind and road noise. Its the rattling towards the beginning of the video. The louder at the end I think is my keys.

Also even if it is a fuel issue, Its still a good idea to get a set of matching heads.

that is pretty close to what mine sounds like. i filled up after school today with mid grade and as of right now i cant here it but i will find out for sure tomorrow. and let you know. i will definitely be looking into a matching set of heads. I have 2 sets I might just rebuild one set or just clean them up and put them on for the time being im not sure what to do cause i have different options. I pulled the original 4 bolt 350 out of the truck after I spun a bearing ( craziest thing i have ever seen it was melted all sorts of crazy i have pics if interested.) i could rebuild that one and put it back in (the one now is a 2 bolt) or just get a set of heads put them on and then when it comes to rebuilding the other i can swap them onto the new one. I'm just running out of time because I leave for college this summer. let me know what you think i should do.

 

[Dutch Rutter]

that is pretty close to what mine sounds like. i filled up after school today with mid grade and as of right now i cant here it but i will find out for sure tomorrow. and let you know. i will definitely be looking into a matching set of heads. I have 2 sets I might just rebuild one set or just clean them up and put them on for the time being I'm not sure what to do cause i have different options. I pulled the original 4 bolt 350 out of the truck after I spun a bearing ( craziest thing i have ever seen it was melted all sorts of crazy i have pics if interested.) i could rebuild that one and put it back in (the one now is a 2 bolt) or just get a set of heads put them on and then when it comes to rebuilding the other i can swap them onto the new one. I'm just running out of time because I leave for college this summer. let me know what you think i should do.

I'm sure there are a lot of guys here who can help point you in a good direction on which heads to go with, as well as everything needed to get this rattle/ping behind you. Definately check your timing on that motor if you can. Also make sure to post up the casting numbers of the different heads you have and maybe a photo because the heads for these motors vary quite a bit. Most I know is that you try to stay away from the lite heads (what my dad always told me) that is all I know about which ones are best. We do always like to see carnage pictures but It may be more beneficial to you if you start a build thread for your truck, that way it'll keep track of where your at with everything.

The 2 bolt will be fine to run so long as its all setup and working correctly, and your not trying to build it into some kind of 500hp monster. Definitely keep the 4 bolt for future plans, especially if its numbers match up with your truck.

 

[Obwonkonobe]

I just read through and seeing mismatched heads(not to mention a 305) on a 350 made me cringe, I would think you could put serious wear on the motor if the heads are mismatched because each bank is making uneven amounts of power.

Id defiantly go vortec, just grab a carb manifold from summit and some vortecs from summit or a yard(look for body damage on the car, its a good sign the motors decent), maybe craigslist if youre feeling risky

 

[Michael Nielsen]

I'm sure there are a lot of guys here who can help point you in a good direction on which heads to go with, as well as everything needed to get this rattle/ping behind you. Definately check your timing on that motor if you can. Also make sure to post up the casting numbers of the different heads you have and maybe a photo because the heads for these motors vary quite a bit. Most I know is that you try to stay away from the lite heads (what my dad always told me) that is all I know about which ones are best. We do always like to see carnage pictures but It may be more beneficial to you if you start a build thread for your truck, that way it'll keep track of where your at with everything.

The 2 bolt will be fine to run so long as its all setup and working correctly, and your not trying to build it into some kind of 500hp monster. Definitely keep the 4 bolt for future plans, especially if its numbers match up with your truck.

It's not gonna be a high horsepower motor it's just a daily driver so I'm totally okay with going to rebuilt stock heads. I'll keep the 4 bolt for later probably after I get out of college. I Just need it to run good to make a 300 mile trip several times as that's how far away my school is. If I end up finding time to swap the heads I'll definitely post some pics up. I'll think about putting up a build thread for my truck.

I just read through and seeing mismatched heads(not to mention a 305) on a 350 made me cringe, I would think you could put serious wear on the motor if the heads are mismatched because each bank is making uneven amounts of power.

Id defiantly go vortec, just grab a carb manifold from summit and some vortecs from summit or a yard(look for body damage on the car, its a good sign the motors decent), maybe craigslist if youre feeling risky

I thought the same thing and I was really upset with the guy that sold it to me when I found out. I can't get a set of heads from summit they are to expensive. I'm still in highschool right now. I might go check a local yard though.

I put mid grade gas in and drove it today and the ping went away for the most part but when I came to a stop after doing about 70 and took off again I heard it pretty loud. I also believe my a/f ratio is off cause when I punched it to about 1/2 throttle it sucked air and died for a second

 

[4WDKC]

It's not gonna be a high horsepower motor it's just a daily driver so I'm totally okay with going to rebuilt stock heads. I'll keep the 4 bolt for later probably after I get out of college. I Just need it to run good to make a 300 mile trip several times as that's how far away my school is. If I end up finding time to swap the heads I'll definitely post some pics up. I'll think about putting up a build thread for my truck.

I thought the same thing and I was really upset with the guy that sold it to me when I found out. I can't get a set of heads from summit they are to expensive. I'm still in highschool right now. I might go check a local yard though.

I put mid grade gas in and drove it today and the ping went away for the most part but when I came to a stop after doing about 70 and took off again I heard it pretty loud. I also believe my a/f ratio is off cause when I punched it to about 1/2 throttle it sucked air and died for a second

The thing about vortec heads from a yard is by the time you have them check for cracks, decked to guarantee they are flat, valve job, new seals, springs to match a cam and screw in studs you are at about the same price as https://sdparts.com/i-23901396-sdpc...der-head-with-0-525-valve-spring-upgrade.html . I am finishing up swapping my truck

 

[Dutch Rutter]

Being on a tight budget your best bet might just be to rebuild your 350 heads, Plus what 4wdKC just said above. For the Vortec heads, they are easy power with great flow if you can swing them. They do come up on my local Craigslist time to time for not too bad of pricing. Most yards around here pull all of the motors and sell them separately but you can get just a set of heads from them. With both of these options I would end up rebuilding the heads anyway, or at least getting them inspected.

I'm going to guess that your timing is too far advanced which is causing the rattle. The higher grade of gasoline at this point is a temporary "bandaid". We do still need to find the underlying cause. This link talks about it in great detail http://www.onestopauto.com/What-causes-spark-knock.html Your A/F mixture will attribute to it but I would check that timing out first, make sure its good then adjust the carb. While doing this its a good idea to run the fuel you will normally be running. You do not want to set everything for running a higher octane, then expect it to run the same with lower octane gas.

The 305 head on a 350 also will need to be addressed as that wont be a long lasting solution. I've never heard of that so someone else will need to touch on if that could be a cause of this noise.

 

[1987 GMC Jimmy]

If it were me, I’d keep the driving to a minimum with the heads like that. You can get this done quickly and cheaply if you throw on a set of stock heads that you have. If it were me, I’d have them rebuilt so they’re fresh. Hopefully, you can trust the bottom end after a, knowing how the builder took care of business and b, after putting it through a tumultuous combustion situation with those heads.

 

[4WDKC]

Being on a tight budget your best bet might just be to rebuild your 350 heads, Plus what 4wdKC just said above. For the Vortec heads, they are easy power with great flow if you can swing them. They do come up on my local Craigslist time to time for not too bad of pricing. Most yards around here pull all of the motors and sell them separately but you can get just a set of heads from them. With both of these options I would end up rebuilding the heads anyway, or at least getting them inspected.

I'm going to guess that your timing is too far advanced which is causing the rattle. The higher grade of gasoline at this point is a temporary "bandaid". We do still need to find the underlying cause. This link talks about it in great detail http://www.onestopauto.com/What-causes-spark-knock.html Your A/F mixture will attribute to it but I would check that timing out first, make sure its good then adjust the carb. While doing this its a good idea to run the fuel you will normally be running. You do not want to set everything for running a higher octane, then expect it to run the same with lower octane gas.

The 305 head on a 350 also will need to be addressed as that wont be a long lasting solution. I've never heard of that so someone else will need to touch on if that could be a cause of this noise.

It was common practice yesterdecade when there wasnt good heads available and this practice increased compression the smog motors were missing. But pairing it with a different head on the other side is not normal practice.

 

[Dutch Rutter]

It was common practice yesterdecade when there wasnt good heads available and this practice increased compression the smog motors were missing. But pairing it with a different head on the other side is not normal practice.

Here you go @Michael Nielsen You have a few things that need addressed. The higher compression from the 305 head would also contribute to the ping/rattle noise. Plus end up causing some havoc else where down the line.

If it were my truck and I was in your shoes, tight budget and needing something reliable, I would do exactly as @1987 GMC Jimmy said. With changing the heads out you will also end up addressing several of the other possible problems. Such as possible air Intake leak, the compression, should also set your timing, then as everything is getting finished up adjust the carb.

 

[Michael Nielsen]

The thing about vortec heads from a yard is by the time you have them check for cracks, decked to guarantee they are flat, valve job, new seals, springs to match a cam and screw in studs you are at about the same price as https://sdparts.com/i-23901396-sdpc...der-head-with-0-525-valve-spring-upgrade.html . I am finishing up swapping my truck

I'll look into it and see what I can find. I'll have to call them and see what the price is gonna be. I don't have a whole lot of cash to work with.

Being on a tight budget your best bet might just be to rebuild your 350 heads, Plus what 4wdKC just said above. For the Vortec heads, they are easy power with great flow if you can swing them. They do come up on my local Craigslist time to time for not too bad of pricing. Most yards around here pull all of the motors and sell them separately but you can get just a set of heads from them. With both of these options I would end up rebuilding the heads anyway, or at least getting them inspected.

I'm going to guess that your timing is too far advanced which is causing the rattle. The higher grade of gasoline at this point is a temporary "bandaid". We do still need to find the underlying cause. This link talks about it in great detail http://www.onestopauto.com/What-causes-spark-knock.html Your A/F mixture will attribute to it but I would check that timing out first, make sure its good then adjust the carb. While doing this its a good idea to run the fuel you will normally be running. You do not want to set everything for running a higher octane, then expect it to run the same with lower octane gas.

The 305 head on a 350 also will need to be addressed as that wont be a long lasting solution. I've never heard of that so someone else will need to touch on if that could be a cause of this noise.

I've got a set of stock ones at home that came off my old 350 that I could have freshend up. I actually just backed the timing off the other day I went back to far to the point it would idle bad and diesel after being shut off. So I moved it forward until it ran okay and wouldn't have any problems shutting down.

If it were me, I’d keep the driving to a minimum with the heads like that. You can get this done quickly and cheaply if you throw on a set of stock heads that you have. If it were me, I’d have them rebuilt so they’re fresh. Hopefully, you can trust the bottom end after a, knowing how the builder took care of business and b, after putting it through a tumultuous combustion situation with those heads.

Sadly it's my only car and it's my daily driver I'll have to wait for either a long weekend or until I know I can get it done in a weekend. When I got the engine i took the pan off and looked inside and it was brand new. The pistons where new the rods didn't even look like they had been run yet. I'm pretty sure it's okay if not I've got 2 other 350s that are good for a rebuild.

Here you go @Michael Nielsen You have a few things that need addressed. The higher compression from the 305 head would also contribute to the ping/rattle noise. Plus end up causing some havoc else where down the line.

If it were my truck and I was in your shoes, tight budget and needing something reliable, I would do exactly as @1987 GMC Jimmy said. With changing the heads out you will also end up addressing several of the other possible problems. Such as possible air Intake leak, the compression, should also set your timing, then as everything is getting finished up adjust the carb.

I've got a lot of things to think about. Ill bust a set of my old heads when I get home and see what's going on. Bout.ti drive 70 down the highway and pray nothing goes wrong.

 

[1987 GMC Jimmy]

I’m sure it’ll work out. I feel you on the school situation. Some people have a situation where they can depend on others for rides and what not. That wasn’t me. My high school was three and a half hours from home, and only one girl from my town went there. I didn’t want to ride with her, though. I’m also going to summer school in June to pick up six hours so my senior schedule isn’t hellacious.

 

[Michael Nielsen]

I’m sure it’ll work out. I feel you on the school situation. Some people have a situation where they can depend on others for rides and what not. That wasn’t me. My high school was three and a half hours from home, and only one girl from my town went there. I didn’t want to ride with her, though. I’m also going to summer school in June to pick up six hours so my senior schedule isn’t hellacious.

I'm at school before anybody else so can't get a ride I also have to take my brother. So I'll figure it out. I gotta pull down a set of my old heads and take a look at em to see what's going on. I can get a set of rebuilt ready to bolt on stock 882 heads with 1.94/1.5 valves in them for 300 bucks