Mopar 350 Stroker

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MOPAROFFICIAL said:
Refresh maybe ? What heads?
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I can tell you our strong drag racing teams never run last seasons head and intake gaskets, never. Plus I bet they get there eyes and Mic's on it and make sure there is nothing that could blow apart and ruin a good block or heads, like you said, they are tore apart every season
 
Racingcowboy89 said:
Okay these are 3.97 piston. These are correct then.
View attachment 1716488988
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Did you remeasure your pin diameter and top of piston to top of pin bore yet? Calipers will be fine for these approximate measurements since all you are trying to do here is figure out what you have. Zero them out and hold them square when measuring. Figure out what you have first.
 
92b said:
Did you remeasure your pin diameter and top of piston to top of pin bore yet? Calipers will be fine for these approximate measurements since all you are trying to do here is figure out what you have. Zero them out and hold them square when measuring. Figure out what you have first.
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Someone from FABO that lives close to the guy should go help him. Im not sure he grasps the basics of what needs to be measured and how to do it accurately.

Trying to explain and teach this stuff on a forum is difficult at best.
 
Illahe said:
If you’re on a budget, you should scour the ads and wrecking yards within your vicinity for a donor 273 that has the adjustable rocker arms. You could use the crank and the valve drain off it and throw the rest in the dumpster.
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Being that the 318 engine has concrete filler in it, it take a lot to blow it. To build a 550 HP with either a 318 or 340 or 360 crank would have to be the goal and only option? I have as the pistons & rods were used for drag racing before. If I use a 340 or 360 crank as I understand that I have to downsize the journals for the rods, I would have to get a machine shop to rebalance a crank. I might as well pay the machine shop to fit the rods on a 340 or 360 crank.
 
Racingcowboy89 said:
Being that the 318 engine has concrete filler in it, it take a lot to blow it. To build a 550 HP with either a 318 or 340 or 360 crank would have to be the goal and only option? I have as the pistons & rods were used for drag racing before. If I use a 340 or 360 crank as I understand that I have to downsize the journals for the rods, I would have to get a machine shop to rebalance a crank. I might as well pay the machine shop to fit the rods on a 340 or 360 crank.
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With enough compression 475 hp may be achievable with enough cylnder head.

I would reach out to Locamotion or GTX JOHN. Without some experience in building a small bore it could be a stretch.

I’ll post up a photograph of a proper windage tray set up. Controlling is gonna be imperative for you for to achieve your goal.
 
Racingcowboy89 said:
Being that the 318 engine has concrete filler in it, it take a lot to blow it. To build a 550 HP with either a 318 or 340 or 360 crank would have to be the goal and only option? I have as the pistons & rods were used for drag racing before. If I use a 340 or 360 crank as I understand that I have to downsize the journals for the rods, I would have to get a machine shop to rebalance a crank. I might as well pay the machine shop to fit the rods on a 340 or 360 crank.
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Filling the block does little to fix it.

Im still trying to figure out what crank and pistons you have.
 

Okay. A little education may be in order here. 273/318/340 cranks all share the same stroke of 3.31 inches and 2.5 main journals and 2.125 rod journals. The only differences are cast or forged construction and balance factor. 273 and early (pre 1973) 318 cranks are going to be balanced for the smaller and lighter bushed rods that came in those engines. 340s are going to be balanced for larger rods and heavier pistons. Your early (pre 1970) 318 will have the most likelihood of having a forged crank. Being you don’t have a crank that was originally outfitted to your application, i myself would look at getting a mopar specific pre balanced rotating assembly and pistons. @PROSTOCKTOM here is a licensed Molnar and JE/Diamond/Icon dealer. First and foremost, though, I would be getting the cylinder bores professionally measured for concentricity and taper to see if what you have is usable before investing too much into it.
 
Your present sbc Chevy piston and rod combo limits you to the 3.31 inches stroke size. I’m thinking those pistons could also be LS specific, or possibly custom made. I can’t see it as originally being built for a high rpm drag race application without valve reliefs in the pistons, though.
 
Newbomb Turk said:
You can’t accurately measure a piston with calipers. Damn.

You need help from a machinist. You are incapable of taking critical measurments.

Just friendly advice.
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While this is true, calipers measurements are close enough to get him to the point where he knows what he is talking about a bit. Look at where he was before started this thread. I've seen racers hone cylinders measuring with the piston and feeler gauges. And these guys were well respected diesel mechanics who owned an established repair shop using a honing machine, not a ball hone and a hole shooter.
 
Garrett Ellison said:
Your present sbc Chevy piston and rod combo limits you to the 3.31 inches stroke size. I’m thinking those pistons could also be LS specific, or possibly custom made. I can’t see it as originally being built for a high rpm drag race application without valve reliefs in the pistons, though.
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The rods are the only thing Chevrolet. Ross told me that they are Mopar pistons, that they were custom made, and Ross said they were a 3.97 bore. That is what Ross told me when I called them back in April of this year.
 
Illahe said:
If you’re on a budget, you should scour the ads and wrecking yards within your vicinity for a donor 273 that has the adjustable rocker arms. You could use the crank and the valve drain off it and throw the rest in the dumpster.
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The closed chamber heads too. Just send them to Charles servedio for porting withe magnum size 1.94/1.6 valves with 8mm stems. Send him your intake and your fuel makin happener as well for the full port job. That will definitely get you down the road right quick.
 
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You may also check around with Eagle or Scat for a blemish 3.31 inch steel crank being that you'd have to have the rod journals turned down anyway. A forged 340 crank from here would also be a good proposition for modification being that it should only need weight taken from it with the SBC rods and (hopefully) lightweight Ross pistons. I would still take the block and pistons for measurement first. The pistons are hopefully marked to the individual bores they were originally sized for, but could be matched back up.
 
Garrett Ellison said:
You may also check around with Eagle or Scat for a blemish 3.31 inch steel crank being that you'd have to have the rod journals turned down anyway. A forged 340 crank from here would also be a good proposition for modification being that it should only need weight taken from it with the SBC rods and (hopefully) lightweight Ross pistons. I would still take the block and pistons for measurement first. The pistons are hopefully marked to the individual bores they were originally sized for, but could be matched back up.
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I could build that 318 block for road racing instead of drag racing as I have a 2nd 3.31 cast iron crank ( casting number #3751841). I understand it handle up to 500 HP. With road racing it's about a fast driver instead of fast car?
 
If your hoping to get 475 hp out of your short block, the attached parts should get you in the neighborhood with 12:1 compression.

106 would be my choice on the lsa, but Keven @Schnidercams will know what it’s going to take.

IMG_4443.jpeg




IMG_4441.jpeg


IMG_4440.jpeg


IMG_4442.jpeg


IMG_4439.jpeg
 
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Newbomb Turk said:
Right. What are you, four pages in and NO ONE here told you the truth? Lots of “pros” on here who should have told you from the first 5 posts you’re using the wrong tool.

So skip it. Don’t buy the proper tools. Just keep struggling.

Edit: cranks are cheap enough today that turning the mains down on a 360 is just dumb. Even if you already have the crank.

Sell it buy the right ****.
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I'm just watchin. This is better than a dan the man thread.
 
Newbomb Turk said:
Then spend the money to buy a set of MICROMETERS and learn to use them. Throw those calipers in the drawer and only use them when the **** you are measuring doesnt matter.

And make sure the micrometers have standards in the set.

https://www.amazon.com/Anytime-Tools-Micrometer-Machinist-Precision/dp/B000JMW4AS/?tag=fabo03-20


Here you go. 0-6 inch micrometers with standards. This is what you use when **** matters.
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Thanks for that. I actually need a new set. Mine is OLD.
 
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