Speedmaster Rods, can i trust them?

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Blaine Davis

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So my dad is building a 340 for his drag car, its been in the works for a while and hes got most of the engine parts
The basic rundown is its a 30 over 340 block with a stock stroke forged eagle crank, mopar performance .590 solid lift cam, forged speed-pro pistons at 12.5/1 compression, edelbrock performer RPM heads, Harland sharp rockers, a Wieland Tunnel ram topped with 600cfm Holleys, and of course speedmaster H-beam rods
We've recently had some issues dealing with speedmaster and their chevy rocker arms, so its shaken our faith in the company, but he all ready bought the rods before hand, with all that money he has in everything else i would hate for a thrown rod to destroy it all in a moment, so were wondering if anyone has used their rods for higher performance use and what was your experience?

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I would use ohio crankshaft rods.
Its not where they are made as many are forged overseas... its who is checking/QC and machining them...and is speed master a in house machine shop ..or a parts warehouse. Find out the weight too.
 
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I wouldn't lose sleep over them, they are stronger than OEM and even those were strong!
 
I would use ohio crankshaft rods.
Its not where they are made as many are forged overseas... its who is checking/QC and machining them.
Yea, i think all the rods are pretty much forged in the same place anymore, i will say these look really nice actually, and they all weigh exactly the same, i think where they cheep out is the rod bolts, they dont use ARP bolts and they dont give much much info on what they do use, the least we would do is use ARP bolts and have the rods checked and resized if needed

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Kinda depends on how fast you spin em.
I'd trust them no problem to 6500, maybe 7000, if the bottom end clearance is right.
9000 rpm, not so much.
If I were buying rods tomorrow ? Molnar.
 
Speedmaster H beam rods weight 725 grams....I have used a set in a bracket motor spinning 6500 with no problem...

I have had H beam rods that weight 660 grams and 680 grams....
 
Kinda depends on how fast you spin em.
I'd trust them no problem to 6500, maybe 7000, if the bottom end clearance is right.
9000 rpm, not so much.
If I were buying rods tomorrow ? Molnar.
I think the most it would ever see is 7000 and that would be screaming, i know i definitely dont have it in me to crank it up to 9 grand lol
 
Why the heavy piston ?
He bought them when he first built the motor in the 90s and his plan is to reuse them i think, but this was when there wasnt a hole lot of other good options, then the 340 had a cast crank, 508 cam, .202 j head and a M1 intake, it ran 12s then, also it had a factory frame and floor stil

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nope.....have no access to dyno...and dont care what the dyno says cause they are usually inflated....but the 75 Duster ran 11.19 @ 118.56 in Vegas air.
 
I consider that moving along pretty good, what other internals did you have?

.030 360 stock stroke...Speedmaster cnc heads,Speedmaster rods, MP571 cam, Holley SD, TTi headers, Crane rockers, 904 tranny, 4.30 gears...8 inch converter
 
Thats good to know, do you know roundabout what the engine put out?
nope.....have no access to dyno...and dont care what the dyno says cause they are usually inflated....but the 75 Duster ran 11.19 @ 118.56 in Vegas air.
Assuming 3300lbs with driver, Wallace says 465hp, at sea level. Probably closer to 500 to run that in lousy air, at altitude.
 
.030 360 stock stroke...Speedmaster cnc heads,Speedmaster rods, MP571 cam, Holley SD, TTi headers, Crane rockers, 904 tranny, 4.30 gears...8 inch converter
Thats sounds like a good set up, and his 340 has a shorter stroke so thats gonna put less strain on the rod that way
 
I would go with the scat I beams good light rod.
I had a friend build a 360 with scat I-beams and a scat stroker crank, something was real wrong with that build, the big ends of the rods varied in thickness and he had to pair thinner with wider ones so they had clearance and didnt bind
 
I had a friend build a 360 with scat I-beams and a scat stroker crank, something was real wrong with that build, the big ends of the rods varied in thickness and he had to pair thinner with wider ones so they had clearance and didnt bind
Wow that would really suck! I haven't heard nothing but great reviews and plan on using them on my 372 build.
 
360 has a lighter piston....less stress on rod and crank....revs up faster
Im just talking about as far as the stress from a farther throw is concerned, he does have the big old speed pro pistons and i dont remember their weight off the top of my head, they were lightened though, but they have 12.5/1 compression so that makes forces on the rods way higher
 
The old 7035 speed pro piston weights about 660 grams..plus a 160 gram pin......stock rods weight about 740 grams.....
 
Wow that would really suck! I haven't heard nothing but great reviews and plan on using them on my 372 build.
Yea it sounds crazy, i wouldn't have believed if it i wouldn't have seen it myself, it was probably just a freak thing because i think everything about that build ended up being cursed lol
 
And as always, have all of them checked. "Out of the box" can bite you in the butt.
 
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