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Rebuild current SBC 350 engine or go different route.


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.Hello guys, I’ve posted the same topic on S30 forum and I won’t to see if here can also get some information. 
I have my S30 and it already has a 350 in it, I found out some milky ( hard to see) stuff on the radiator cap so I assume it’s a blown head gasket, it has a custom driveshaft, turbo transmission, it has an Edelbrock  6073 aluminum heads conversion kit and performer manifold, 1406 carburetor , hooker headers, ceramic coated twin Anasa exhaust system... my concern here is that I might be in the need to rebuild the whole engine, and hope the heads aren’t cracked as aluminum heads tent to crack, and if that’s the case I am wondering if it’s cheaper rebuilding the current engine or buying a new one, and if the heads are reusable use them on the new or rebuild engine, or should I go a different route, with a different swap, I was thinking about a RB25, I’ve seen some around $2500 with Transmission online (but I’ve heard that parts are a pain to get them), if so do I need special modifications? In the conversion to a V8 350 I noticed  it was spent over $3300, i don’t want to complicate things and make it easier  with your advice and suggestions, I don’t want to get ripped off by a mechanic so I’ve been doing some research and what better place that with experienced Z drivers. Thanks for your support.

( I already spent many months in bed, about 8 months for cancer then 6 months in a hospital  so now that I can walk want to fly on my Z lol) 

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3 hours ago, Jaconense777 said:

 I found out some milky ( hard to see) stuff on the radiator cap so I assume it’s a blown head gasket,

 

No offense intended, but this is (a terrible way) not a good way diagnose an engine problem.  The engine barely cares what's in the radiator.  What's in the oil?  How does the dipstick look?

Edited by NewZed
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  IMG_20200408_095322_179.jpg.e457fc718e97d4d9094677267220d9a2.jpgWhen I bought the car I was running,  but then I changed the valve covers gaskets and header gaskets so it was smoking and I thought it was because of that.

But when I removed the valve covers I  noticed like milk or coffe color with the oil, the oil on the dipstick is clean, I wonder if is because the guy who sold me the car changed the oil to cover up any problem it might had, I did not have the chance to run the car enough after acquiring it as I was il ,   I also found antifreeze once by one of the intake manifold bolts, so I am trying to fix it now and a street mechanic i was told that it could be a blown head gasket  for the radiator cap. but once they start saying of it might be this or that and their prices it's hard to trust.  
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Possibility of head gasket issue:  perform a compression test on the motor.

 

"Smoking problem":  where is it smoking from....tail pipe or engine compartment?  (Edit:  your videos weren't loading for me earlier; but they seem to be now....I'll go back and review now that they're working.  I agree with NewZed's assessment for smoke in the engine compartment; as well as coolant sitting on top of intake manifold.)

 

(Another) engine swap:  How are your mechanic skills?  If you're doing the work, it can be done affordability or expensively, depending on how wild you get with it.  If it's a high-end swap like an RB, it will be expensive (quite a bit more than $3300).  If you're paying someone else to do the work, it will be WAY more expensive.

 

Goals for the car:  what are they?  You haven't mentioned why you bought the car or what you plan to do with it (I.e. Intended application), but that should guide all your decisions regarding mods and upgrades.

 

Budget:  unless you're Bill Gates, decide now what you want to spend on the car, and moderate your goals based on that budget.  Engine swaps and performance builds will go through cash like you wouldn't believe, and a lot of people unfortunately don't learn this until they're deep into the build....and end up selling the project, half-finished and torn apart st a huge loss.

Edited by jhm
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Smoke coming from the engine bay, assuming that the car has a full exhaust system on it, is usually from oil on the headers, from a leak or from recent work.  Headers get hot very fast and the oil will vaporize almost as soon as the engine starts.

 

In your second video whatever you were scraping at is barely visible, and the oil on the rocker arm and top of the head doesn't look bad.  It might be that you're just not familiar with what you're seeing.  If the engine has been sitting a long time there might a small amount of condensation that will burn off as the engine runs.  If you're really worried about coolant in the crankcase just drain the oil and see what comes out.  If there's a lot of water it will separate from the oil.  You'll get a layer of water then the oil.  Or the oil will look milky because the water has been whipped in to it by the crankshaft.

 

If you think that you might have coolant leaking in to a cylinder, just pull the spark plugs and examine them.  Coolant is a great cleaning agent in a hot combustion chamber.  You'll either have fouled plugs because of loss of compression and/or water, or clean plugs next to normal, or they'll look okay.  But there will be signs if you have a problem.

 

Coolant on top of the manifold probably has nothing to do with coolant inside the engine, unless the manifold i not seated properly.  But if that were the case you'd probably have intake vacuum leaks also, causing problems with the engine running.  Separate those two things in your mind. 

 

Good luck, the engine sounds pretty good, at least as far as phone cameras go.  You might create a youtube page and load your videos there.  Easier to share and they'll play faster.

 

 

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12 hours ago, jhm said:

Possibility of head gasket issue:  perform a compression test on the motor.

 

"Smoking problem":  where is it smoking from....tail pipe or engine compartment?  (Edit:  your videos weren't loading for me earlier; but they seem to be now....I'll go back and review now that they're working.  I agree with NewZed's assessment for smoke in the engine compartment; as well as coolant sitting on top of intake manifold.)

 

(Another) engine swap:  How are your mechanic skills?  If you're doing the work, it can be done affordability or expensively, depending on how wild you get with it.  If it's a high-end swap like an RB, it will be expensive (quite a bit more than $3300).  If you're paying someone else to do the work, it will be WAY more expensive.

 

Goals for the car:  what are they?  You haven't mentioned why you bought the car or what you plan to do with it (I.e. Intended application), but that should guide all your decisions regarding mods and upgrades.

 

Budget:  unless you're Bill Gates, decide now what you want to spend on the car, and moderate your goals based on that budget.  Engine swaps and performance builds will go through cash like you wouldn't believe, and a lot of people unfortunately don't learn this until they're deep into the build....and end up selling the project, half-finished and torn apart st a huge loss.

Thanks for your reply, I love Datsun s30’s so I got this one to keep it, well cancer had me in bed for over 8 months so my wife and some friends helped me out getting this car to keep my mind busy and to get up from bed, I started working on it, cleaned the under carriage and painted all the wheel arch’s, then again,  honestly I almost didn’t make it out alive form the hospital, many times I was told that I wasn’t  make it, internal bleedings, hoses in the chest (ports), intestines paralyzed, they said problems with the brain, like a stroke but is a new disease call Miller fisher syndrome and was diagnosed with guillian-barrel etc,   This was my 2018 and 2019 then you know what was 2020 for everyone else lol, I might sell it in the future, but I was told that the smoke is normal for the new exhaust gaskets to smoke, as they’re getting cured, I changed all the exhaust system gaskets from the the engine to the tail pipe, I changed them because smoke was coming out of the left side header by the gaskets and I had misfires, I replaced the spark plugs but one thing I noticed is that the engine had some spark plug Foulers , then the car was kinda weak, I didn’t found any oil on the spark plugs but the car was running kinda weak,  maybe like you guys said to check the compression, I also changed the power wires to the distributor as thy has some rust on them, and we’re lose. I had a “professional “ from Bristol audio to come and install a new alarm in my car, he broke the steering wheel column cover and after that the car’s battery dies very fast, I ever had this problem before. (I cleaned the fuel lines and rebuilt the fuel tank even it got ceramic coated inside and the fuel pump is a loud Holley red, there is fuel in the carburetor , ) what is the best tool to check the compression? And if that’s the case what can I do to fix that problem? Is it expensive? Man looks like I have time to write big essays lol

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6 hours ago, NewZed said:

Smoke coming from the engine bay, assuming that the car has a full exhaust system on it, is usually from oil on the headers, from a leak or from recent work.  Headers get hot very fast and the oil will vaporize almost as soon as the engine starts.

 

In your second video whatever you were scraping at is barely visible, and the oil on the rocker arm and top of the head doesn't look bad.  It might be that you're just not familiar with what you're seeing.  If the engine has been sitting a long time there might a small amount of condensation that will burn off as the engine runs.  If you're really worried about coolant in the crankcase just drain the oil and see what comes out.  If there's a lot of water it will separate from the oil.  You'll get a layer of water then the oil.  Or the oil will look milky because the water has been whipped in to it by the crankshaft.

 

If you think that you might have coolant leaking in to a cylinder, just pull the spark plugs and examine them.  Coolant is a great cleaning agent in a hot combustion chamber.  You'll either have fouled plugs because of loss of compression and/or water, or clean plugs next to normal, or they'll look okay.  But there will be signs if you have a problem.

 

Coolant on top of the manifold probably has nothing to do with coolant inside the engine, unless the manifold i not seated properly.  But if that were the case you'd probably have intake vacuum leaks also, causing problems with the engine running.  Separate those two things in your mind. 

 

Good luck, the engine sounds pretty good, at least as far as phone cameras go.  You might create a youtube page and load your videos there.  Easier to share and they'll play faster.

 

 

Thanks for your reply I don’t have much experience as a mechanic, everything I am doing is based on research and google, I had made many mistakes using you tube as sometimes they explain things as if you were knowledgeable of mechanics, I got the idea of the coolant in the engine as in the video if you look at the left lower corner of the heads looks like there is some coolant or water with the oil, and base on what I was told in the past I assumed antifreeze was getting in the engine mixing with oil, I’ll check the oil and see if there’s any mixtures, it still has the oil the previous owner put into the car, when I looked in to the oil it was good texture and color but he could of have changed the oil to sell the car for a higher price. Also I moved the distributor and it might be out of time as I watched a video on YouTube on scratching the distributor rotor makes better contact and better spark. But my main concern is the engine and the mechanics that always try to rip you off.

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24 minutes ago, Jaconense777 said:

. Also I moved the distributor and it might be out of time as I watched a video on YouTube on scratching the distributor rotor makes better contact and better spark. But my main concern is the engine and the mechanics that always try to rip you off.

 

The engine sounded good but it did sound like the timing might be retarded a bit.  Invest in a decent timing light, they're easy to use and not too expensive.

 

Since the engine ran well with no major knocking noises and the oil did not look bad I'd say don't do anything drastic until you know more.  Don't let anyone, or a youtube video, convince you that you need to replace head gaskets or manifold gaskets or whatever.  Engines can have many small problems and still run well without doing more damage.  Your main concern should be that you have good oil pressure, I'd assume that there is a working gauge, and the oil stays clean.  Low oil pressure is the main killer of all engines.  Most will survive the other stuff, but just run poorly in the meantime.

 

Your title says "rebuild" but there are no signs that you need to rebuild anything.  Besides oil pressure though, your other big concern is that that engine in a Z is just itching to get sideways and leave the road.  Be careful.

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10 hours ago, Jaconense777 said:

Sorry for the Newby questions. Could you please tell me what is that and the purpose? 

 

Very sorry to hear about the health problems.  Big props to you for pushing through all that and continuing to do the things in life you love.

 

Hard to tell from that picture....but I'm guessing it's just a fuel pressure gauge.  You shouldn't really need a fuel pressure regulator with a carb'ed system.  Take a closer picture and post it, if you have the chance to do so.  Mr. Gasket stuff?  My personal opinion is that it's mostly junk; but if it's working for now, I'd leave it until it fails.  I'd recommend sticking with major reputable companies like Holley, Edelbrock and Russell Performance when it comes time to replace components in the air and fuel system.

 

I would recommend changing that small air cleaner at some point, if you have the room to do so.  It's amazing how restrictive an inadequate air cleaner/air filter can be on the engine's performance.

 

For repairs and modifications that you're not comfortable doing yourself, stay away from shady mechanics and repair shops (and there's a million of 'em.)  Go to some car shows or "Cars & Coffee" events, to find out where local car enthusiasts take their cars to be worked on.  Once  find a good mechanic/repair shop, you'll never want to take your car anywhere else.

 

Keep the questions coming....that's what this forum is for!

 

 

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  • 1 month later...

The ideal solution would be to find a local mentor... somebody who knows what to see/smell/touch/hear, whose intuition would quickly diagnose things.  To be learning on one's own, could be intensely rewarding - but just as intensely frustrating.  The learning-curve is easier to ascend, if there's a fellow-traveler.  Unfortunately this is all the harder in the present 'rona cataclysm.

 

I'm going to make a potentially specious, but not entirely phone speculation: the engine is just worn.  Nothing is seriously damaged, but it is "out of tune".  It likely needs some carb and distributor adjustments.  Maybe some gaskets.  Maybe there are carbon deposits, or worst case, bad valve seals.  

 

Can the car be driven as-is?  Does it run sufficiently well, to brave California's highways?  That may be the best (if risky) way to test it.

 

Good luck, and as goes without saying, congratulations on your recovery!

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  • 3 weeks later...

Hello guys, I Also decided and was brave enough to take off the heads (LoL) and found out that there was in deed coolant mixed with the oil. I already sent the heads to a machine shop for a rebuild. A mechanic told me that my crankshaft sounds like a 383 stroker, the pistons has 0.030 written on them and I did a research and shows that a 195cc inner runner volume and 70cc combustion chamber was enough for that type of engine. Could you confirm that? I am going on a 383 direction, it has an edelbrock 1406 and I was told that with spreas modification ( carburetor jet kit) can improve its performance and cfm ratio, as it’s only 600 cfm , it’s in great shape though or should I get a bigger carb? Thanks for all your support.

99C864B9-FB4F-49FA-973A-930B835AF1D3.jpeg.89ca0f54bbee9930ebb77072c3e3fccc.jpeg
Shows rust like in the holes closer to the distributor .

31EE5F11-2834-4D79-928D-3C049F9AD007.jpeg.33b307a2d50419d4a8408754895d62df.jpeg
This how the pistons looks before and after i cleaned them out

 5B823528-67B1-40C2-BA12-B3D8B3E38F47.jpeg.6135f390c99d97b034f597e5a3988f9b.jpeg
as you see the pistons have 0.030 on them.

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Posted (edited)
On 2/12/2021 at 7:54 PM, Michael said:

The ideal solution would be to find a local mentor... somebody who knows what to see/smell/touch/hear, whose intuition would quickly diagnose things.  To be learning on one's own, could be intensely rewarding - but just as intensely frustrating.  The learning-curve is easier to ascend, if there's a fellow-traveler.  Unfortunately this is all the harder in the present 'rona cataclysm.

 

I'm going to make a potentially specious, but not entirely phone speculation: the engine is just worn.  Nothing is seriously damaged, but it is "out of tune".  It likely needs some carb and distributor adjustments.  Maybe some gaskets.  Maybe there are carbon deposits, or worst case, bad valve seals.  

 

Can the car be driven as-is?  Does it run sufficiently well, to brave California's highways?  That may be the best (if risky) way to test it.

 

Good luck, and as goes without saying, congratulations on your recovery!

 

thanks for your wishes. The previous picture shows a lot of carbon buildup on the pistons.I did looked out for a mechanic but he gave me wrong information on how to remove the heads, however it ok as I like to think out of the box and was able to send the heads to a machine shop. Can’t wait to get the heads back and put them back on the car, I am getting a digital torque wrench so I can put them back using proper procedures.

Edited by Jaconense777
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10 minutes ago, Jaconense777 said:

Hello guys, I Also decided and was brave enough to take off the heads (LoL) and found out that there was in deed coolant mixed with the oil. I already sent the heads to a machine shop for a rebuild. A mechanic told me that my crankshaft sounds like a 383 stroker, the pistons has 0.030 written on them and I did a research and shows that a 195cc inner runner volume and 70cc combustion chamber was enough for that type of engine. Could you confirm that? I am going on a 383 direction, it has an edelbrock 1406 and I was told that with spreas modification ( carburetor jet kit) can improve its performance and cfm ratio, as it’s only 600 cfm , it’s in great shape though or should I get a bigger carb? Thanks for all your support.

99C864B9-FB4F-49FA-973A-930B835AF1D3.jpeg.89ca0f54bbee9930ebb77072c3e3fccc.jpeg
Shows rust like in the holes closer to the distributor .

31EE5F11-2834-4D79-928D-3C049F9AD007.jpeg.33b307a2d50419d4a8408754895d62df.jpeg
This how the pistons looks before and after i cleaned them out

 5B823528-67B1-40C2-BA12-B3D8B3E38F47.jpeg.6135f390c99d97b034f597e5a3988f9b.jpeg
as you see the pistons have 0.030 on them.

About the carburetor I found this on google 5871DC68-D0C9-42C1-848C-391B704FF357.png.98b5587c378dfe26375a4573e2f81064.png

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The coolant/oil mix suggests a blown head gasket (best case), cracked heads (can be repaired) or cracked block (a serious problem).  it may make sense to pull the engine, and to completely disassemble it.  The machine shop will then perform tests to ascertain if the blocks is cracked.  Even if the block is fine, there may be merit to installing new bearings (crank and rod) and new rod bolts.

 

The stroke of the crank can be easily confirmed by measuring the vertical displacement of a piston across one half-revolution.  If it's a 383, that displacement (which is the stroke!) will be".  If it's a "normal" 350 (nominally) engine, the stroke will be 3.48".  The difference is sufficiently large, that it can shouldn't require precision gauges (like a dial indicator) to measure it.

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  • 1 month later...

Hello guys I just want to give you guys an update and continue with this old tread, I already rebuilt the engine and it worked good, I took the heads to machine shop for a rebuilt (it was a blown head gasket antifreeze got mixed with the oil)however I decided to change the distributor harness because it was kinda loose, so because the wires were a lil different to the stock one I decided to adapt it, it started right up. I went for a ride and the car was running really good, the problem is that i heard a big sound by the distributor  and smoke coming behind the car , then my dad decided to bring me gas and put some on the carburetor, it was causing a lot of flames, I towed the car back home and the mechanic opened the distributor but it looks good but it makes a noise when I am trying to start the engine, and the fuel comes right up the carburetor, like explosion the mechanic checked inside the engine by the distributor and looks very clean and the rotor it gets aligned all the time, he thinks it might be the timing chain, now it won’t start, he said. The distributor rotor doesn’t turn the way it supposed to, I’ll record it next time he tries to start it.he is coming next Tuesday so I am getting a new distributor and have it handy just in case that’s the problem.

now the golden question.... which distributor is better for my application it’s a good wrench gen 1 4 bolt pre 1985, 6073 heads,performer intec, 1406 carb, I was looking into ACDelco 93440806, MSD8362,  or autozone Duralast Gold New Distributor BDLG-GM08 just because I have $50 store credit(could use it on oil change though) I want to get the best option for the money, budget is around $200s, spans do you guys have any idea or suggestions about what could be related to my problem? 
thanks guys for your support on this matter. Sorry guys for the Rocky questions.

 

5DBADC72-C6FD-40C3-914F-20E65C1481E3.jpeg.f8f642dfa52a20e249c76642109d753f.jpeg

 

 

 

 

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Remove the valve covers and inspect the rockers and pushrods.  The latest malady sounds like what happens with a "wiped" flat tappet cam and bent pushrods.  Also manually turn the crank-bolt and check that the valves are opening correctly (that whole 18436572 firing-order thing).  Re-do the "quarter turn trick" if it's a hydraulic cam, and re-set the lash if it's a mechanical cam.

 

It's conceivable that the distributor was installed 180 degrees backwards, so to speak.  That is, spark hits the #1 piston as it's coming up on the... exhaust stroke, instead of the intake stroke.

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