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Old 08-07-2018, 11:37 AM   #1
icdpride
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Default Forged rods with out forged pistons worth it?

So I am rebuilding my 1986 b230f block and I am wondering if forged rods with stock na pistons with new rings would be worth it or just using 13mm rods is pretty much the same at that point because the limit is the piston.
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Old 08-07-2018, 11:53 AM   #2
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What’s your goal for the motor? Btw the 13mm rods are forged... but very bendy.
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Old 08-07-2018, 11:54 AM   #3
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Stock pistons are stronger than stock rods.

If the car is NA... the 13mm will be fine.
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Old 08-07-2018, 12:13 PM   #4
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Originally Posted by 740atl View Post
What’s your goal for the motor? Btw the 13mm rods are forged... but very bendy.
Yeah sorry I mean like aftermarket h beam forged rods.

My goal is start around 250hp probably around 300ish over all, I have done all the supporting mods I think, I have a big turbo, 1000cc injectors and megasquirt
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Old 08-07-2018, 12:13 PM   #5
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Stock pistons are stronger than stock rods.

If the car is NA... the 13mm will be fine.
Yeah its a +t
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Old 08-07-2018, 12:32 PM   #6
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In that case it can’t hurt. Add to your parts list the ma3 chip and get the internal knock sensor. The trick to keeping the ringlands intact is not detonating.
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Old 08-07-2018, 12:45 PM   #7
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Calling JohnMc..... pickup John.......
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Old 08-07-2018, 01:12 PM   #8
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Heh, I have broken both.

From my experience, yes, the 13mm rods are weaker than the stock pistons. I bent a couple of rods with some iffy gas and a little red mist once, the engine grenaded a few days later (presumably bent rods are on a short countdown to being broken rods).

Subsequent builds used H-beam rods and forged pistons. I never broke or bent a rod again, but I did damage a set of the pistons. And a very nice feature of a set of forged pistons isn't so much that they can withstand more abuse (they likely can) but that the failure mode is much more graceful. Instead of breaking, which quickly leads to rods and bock chunks flying out onto the road, they can (sometimes) just bend instead. Due (likely) to running short of fuel with a stock pump, I managed to shatter the rings and bend the upper ring lands on a set of Wiseco forged pistons. BUT: the engine did not blow up, all it did was start making lots of blowby and having low compression. Took it apart, put it back together with new pistons, a bit simpler and cheaper than starting over from scratch again with a new junkyard block.

Then I broke a wrist pin, and even drove it with a fair amount of vigor after I heard the ticking sound for the first time (it didn't sound very serious). The forged piston managed to hang together running 'one sided' while I did that, I'm pretty sure that a cast piston would have broken and I'd have scattered parts again.

Cliff notes: If you screw up and overstress the bottom end somehow, forged pistons are likely to help limit the damage.
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Old 08-07-2018, 01:13 PM   #9
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Quote:
Originally Posted by icdpride View Post
Yeah sorry I mean like aftermarket h beam forged rods.

My goal is start around 250hp probably around 300ish over all, I have done all the supporting mods I think, I have a big turbo, 1000cc injectors and megasquirt
750s, stock long block, stock manifold, cam.
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Old 08-07-2018, 03:46 PM   #10
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So what I am getting is its kinda sort of worth it but not necessarily worth it ?
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Old 08-07-2018, 03:49 PM   #11
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Stock block, rods are the limit. Upgrade rods, rods not the limit. Then it's probably pistons or head gasket.
Depending on where you are and what you do, pistons can take a lot of pressure, forged or not.
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Old 08-07-2018, 03:51 PM   #12
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Quote:
Originally Posted by icdpride View Post
So what I am getting is its kinda sort of worth it but not necessarily worth it ?
What you're getting is anecdotal advice from people that don't care if your motor pops three or four times, no sweat off their noses..


John McC said it: they forged pistons--don't shatter and leave the rod flailing around breaking everything in the whole motor.

Do both.
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Old 08-07-2018, 04:28 PM   #13
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What you're getting is anecdotal advice from people that don't care if your motor pops three or four times, no sweat off their noses..


John McC said it: they forged pistons--don't shatter and leave the rod flailing around breaking everything in the whole motor.

Do both.
Or just take it apart, inspect it, put it back together nice with some glyco rods and deves pistons if needed, and rock on? Or don't bother because a block can be swapped in a day by a half-decent home gamer?

For 250whp, don't bother.
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Old 08-07-2018, 04:30 PM   #14
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For 250whp, don't bother.
If this is your ONLY power goal, then I'm 100% in agreement. 250whp is well documented to be a safe number for a later B230 or B21/23ft.
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Old 08-07-2018, 04:46 PM   #15
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If this is your ONLY power goal, then I'm 100% in agreement. 250whp is well documented to be a safe number for a later B230 or B21/23ft.
Its not my only power goal its just the first goal as I don't have a t-5 to swap for the trans yet my plan is to go much higher after I have that
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Old 08-07-2018, 05:13 PM   #16
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Originally Posted by icdpride View Post
Its not my only power goal its just the first goal as I don't have a t-5 to swap for the trans yet my plan is to go much higher after I have that
How high? Whats your budget? What's your Turbo choice? Drivetrain etc.

That'll pretty much determine how we answer your question.
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Old 08-07-2018, 05:20 PM   #17
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Probably 325-350
Budget $400-500
Current turbo is
Gt35 (a/r .70) ebay turbo with external waste gate
M46 trans g80 in the rear
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Old 08-07-2018, 05:24 PM   #18
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Originally Posted by Harlard View Post
For 250whp, don't bother.
For 250 whp, don't bother with the rods either, then. Just keep it cheap, and accept that if you make a tuning error you're going to swing by a junkyard and pick up another bottom end.

Otherwise, you're putting some $$$ into rods that would get mangled along with everything else if you crack a piston with some unexpected detonation.

So either keep it all cheap, stock, pretty much untouched from the junkyard (13mm bottom end), or if you're going to try to make it stronger, don't half-ass it with rods only, do rods and pistons.

PS EDIT: And really, there is a lot to be said for just keepign a stock bottom end in the car, and learning to tune around it. It sounds traumatic(?) to blow up an engine, but really, the $$$$ worth of shiny super strong rods and pistons will still fail if you hammer the bottom end with a tuning mistake, the onl advantage is that you can (sometimes) still drive it home afterwards. You're still going to be pulling the engine out and apart, only with the $$$$ worth of shiny parts you're waiting weeks and spending another $$$$ to put it back together. With a scattered stock block, $400 and a trip to a junkyard and you're back in business again with a long weekend day worth of swapping motors. Just make sure you fix whatever made it blow up last time.
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Old 08-08-2018, 10:51 AM   #19
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Got it so don't have ass it got, I appreciate all the feed back. Unfortunately redblocks are not that readily available in any of the junk yards in Syracuse Ny.

On last question, should I at least be changing out the hardware on the rods? Are they like head bolts or are the reusable?
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Old 08-08-2018, 11:35 AM   #20
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That budget would be better spent on microsquirt so you can make sure you have good fuel and spark to maintain some reliability.
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Old 08-08-2018, 11:56 AM   #21
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That budget would be better spent on microsquirt so you can make sure you have good fuel and spark to maintain some reliability.
I already have Mega-squirt just working on the tuning part with that
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Old 08-08-2018, 11:58 AM   #22
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Quote:
Originally Posted by icdpride View Post
Got it so don't have ass it got, I appreciate all the feed back. Unfortunately redblocks are not that readily available in any of the junk yards in Syracuse Ny.

On last question, should I at least be changing out the hardware on the rods? Are they like head bolts or are the reusable?
They're not as readily available as they used to be anywhere, but still, it's not *that* hard to find one when you need one. They're not unobtanium.








Yet.
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Old 08-08-2018, 12:35 PM   #23
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Get hoarding. $50 serviceable blocks are still out there. If you want, I guess...
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