Duece
Duece
Thank you sir!
"Ran when pulled"
- Thread starter Duece
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Sedanman
67-9 Valiant specialist
They cut real good when fresh. I would do the piston tops first to dull the edges some or apply some thick oil or grease to the rusty area that your going use it on and use low rpm's and run it up and down the cylinder on the rust. It should polish it away pretty quick.
Factory used tin head gaskets, tin intake gaskets. These are signs that may say nobody has torn it down before.
If it's from the early 90's, it would have had a throttle body injection intake, and a roller cam.
If it's from the early 90's, it would have had a throttle body injection intake, and a roller cam.
Duece
Duece
Yes to all of those things, it was tin gaskets and TBI. Was the different pistons a thing on those engines?
Sedanman
67-9 Valiant specialist
Yep,I have the same year 360 motor. It has 8.1 compression,roller cam,193 hp/292 tq and a .410/.410 lift cam and 308 heads. The 318 is 9.2 comp,170hp,260tq,roller cam with .373in/.400ex and closed chamber 302 heads
Duece
Duece
Man you guys awesome, so much knowledge. One day I will make it to a meet and buy a round or two!!
I'm sure those are factory pistons. I've not had it that situation personally, but I've heard others running into similar situations.
I had an '89 360 TBI like you have listed. In a '89 D150 with 3.21 gears, factory manifolds and single exhaust (I cut off the muffler and put on a turbo muffler) it went 15.30's still using the factory TBI. I was impressed.
Sedanman
67-9 Valiant specialist
They just keep pulling. They have a good engine/trans combo. I wonder what the trans gearing is. I have a 94 5.2 Van and it will pull as long as I keep my foot to the floor
Sedanman
67-9 Valiant specialist
To the OP. If you ever take the timing cover off post a pic of the cam and thrust plate. I'm curious if the cam has a snout for a mechanical pump or not. I know the magnums don't.
Duece
Duece
Timing cover is off, I will snap you a pic when I get a chance.
my '89 not only had the snout, but it had the eccentric for the mechanical fuel pump. All I would have had to do is remove the plate they had blocking the mount for the mechanical fuel pump and I could have threw a carb intake on it with a mechanical fuel pump. Mine also came with a double roller chain.
Sedanman
67-9 Valiant specialist
Cool,my engine is still together and the later LA engine don't have the hole hogged out in the timing cover for the fuel pump,so I'm curious
Sedanman
67-9 Valiant specialist
Nice. I scored my engine from a 91 church van with 77,000 miles. The insides are super clean
I have a cam from a '89 360 TBI roller cam with snout. I'm going to use it in a 318 magnum so I can run a mechanical fuel pump. I'll gain about .030 lift putting it in the magnum because of the 1.6 rockers on the magnum.
Sedanman
67-9 Valiant specialist
The 360 magnums had a .474 lift cam. I'm not sure what the 318 had. My buddy took a stock magnum 360, added an airgap and 750,HEI module conversion with a 4spd behind it,323 gears and it does 13.40 in the 1/4
I don't think .474 lift.... I thinks it's .410 for the magnums also. The 318 mag had more lift than the 360 mag, not by much, but a little. They had 245 hp (net) from the factory, which is 5 more than the '72 340, and more torque.
But yes, 13.40's is very reasonable with that combo. With just a 4bbl and headers, it should be over 300 gross hp, and about 350 ft lbs of torque.
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Duece
Duece
nm9stheham
Well-Known Member
Hmmm... looking at the 3rd pix in the original post, the piston at the far right appears to have the valve pockets rotated 90 degrees from the normal orientation. WTF is up with that? And the valve pockets in the 2nd pix are also not in the right orientation. Sorry, you gotta see what is up there; I'd look underneath and then pull them. Something is definitely not right if I am seeing these pistons correctly.
No, it is not normal at all to have different pistons in an engine. Something is up and you need to partially tear it apart. Having the stock shim gaskets is meaningless as far as being a factory engine; someone could have just thrown it back together with old, used gaskets.
Duece
Duece
You are correct, those 2 pistons are different as well as different orientations....Sum beach
Well, I think that is the clincher...looks like time to do the bottom end as well
Duece
Duece
Anybody have a recommendation on a rebuild kit?
nm9stheham
Well-Known Member
Sorry to point that out! When I saw those 2 pistons, I had to wonder if there are actually con rods in those 2 holes....... or are the piston tops broken off or what? If not con rods, then I would question what happened and is the crank good and straight. But that is all speculation at this point.
IMHO, take it all down first to see what you have to work with. Check (or have checked) the top-to-bottom taper in the bores. If there is too much taper, you can hone it all day long but the rings won't last. Being EFI, hopefully they are pretty good.
FWIW, I tend to just piece together parts that I like. Is this for just a stock running engine? There are a few slightly higher compression ratio, flat topped, stock type cast, 318 pistons out there, at a cast piston price since you are on a budget. Not truly "high compression" but you don't want to end up with the old super-low-compression truck pistons. CR is IMHO the main deficiency in the 318's, so any steps to pick it up are good steps to take.
IMHO, take it all down first to see what you have to work with. Check (or have checked) the top-to-bottom taper in the bores. If there is too much taper, you can hone it all day long but the rings won't last. Being EFI, hopefully they are pretty good.
FWIW, I tend to just piece together parts that I like. Is this for just a stock running engine? There are a few slightly higher compression ratio, flat topped, stock type cast, 318 pistons out there, at a cast piston price since you are on a budget. Not truly "high compression" but you don't want to end up with the old super-low-compression truck pistons. CR is IMHO the main deficiency in the 318's, so any steps to pick it up are good steps to take.
Duece
Duece
It was a great catch on your part, that just saved me a ton of wasted time and energy. Thank you!!
I am going to take it to a machine shop and have them check and rebuild the bottom end of this thing. I am getting out of my comfort zone here and I had budgeted this in as a possibility if things didn't turn out, I really hoped I would get lucky. I like trying things I havent done before, but this may be a little much to bite off on my first motor build.
My plan is to eventually turbo charge this motor, so I dont want to get too high on the CR. I had planned to stay stock with the cam/lifters/pistons but I may as well look for some "better than stock" pistons for a reasonable price so I at least have a matching set
that depends what you want to do, a re-ring kit gaskets and all could be had for $100, and pistons another $100. If you're looking for extra performance it goes up from there
nm9stheham
Well-Known Member
How much boost are you thinking of? If you are going beyond the range of around 7-8 lbs of boost, then I would be looking at a strengthened bottom end. And IMHO, stock type cast pistons are out of the question; you might get by with them for a very low boost use, but maybe not. I have run both forged and hypereutectics in rally 4 bangers with 14-15 lbs boost with no problems, but forged is the preferred type.My plan is to eventually turbo charge this motor, so I dont want to get too high on the CR. I had planned to stay stock with the cam/lifters/pistons but I may as well look for some "better than stock" pistons for a reasonable price so I at least have a matching set
BTW, 318willrun's comment on the piston tops is what made me look more closely. So give him the credit. And I sure would like to know what is up with those 2 pistons, so let us know when you find out.
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