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Forged shortblock limits without Meth

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Old Jul 3, 2018 | 06:58 AM
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Default Forged shortblock limits without Meth

What boost level should I limit myself to with running the shortblock below.
At this time, i want to avoid a methanol kit. My goal is 600rwhp on straight 93.

I have a built 347 shortbkock. Wiseco flat tops, Eagle H beams, New OEM crank. Stock 241s, 10:1 compression.

D1SC kit, 8 rib, Aster bracket, twin 4.5 intercoolers.

I know guys with stock shortbkocks have done 10psi on straight 93, so with mine being forged, what do you think is a safe boost level?

Thanks
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Old Jul 3, 2018 | 07:09 AM
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Swap heads to stock 317s if you want to avoid methanol.
I've been 22 PSI on a stock shortblock on straight 93 and no meth. I'm pretty sure you're not going to be having any issues with a forged shortblock.
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Old Jul 3, 2018 | 07:49 AM
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Originally Posted by JoeNova
Swap heads to stock 317s if you want to avoid methanol.
I've been 22 PSI on a stock shortblock on straight 93 and no meth. I'm pretty sure you're not going to be having any issues with a forged shortblock.
Why go through the trouble of swapping heads if my goal is only 600rwhp and people with stock shortblocks are doing that on 93 octane, a blower cam and 10psi?

I just want an idea on how far i can SAFELY push the forged shortblock before I need methanol. Im guessing with my 10:1 cr, maybe 12psi??.
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Old Jul 3, 2018 | 09:30 AM
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Without meth? Well, as much boost as you can throw at it with timing retarded.

Check plugs as you go to see.

I could see 700rwhp... but the twins and the fuel system will be the bigger issue. Guys have been doing 650+ with high compression procharged LS1s for like 15 years and for a lot of those years, no meth was involved.

With meth, a D1X, ported heads, upgraded FMIC, and the right fuel system, you could do 900.
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Old Jul 3, 2018 | 09:34 AM
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I've had your exact setup before same cubes same pistons rods and even the same heads at 12psi on a cheapo 88mm I made 620 and with less than 1k miles on it I spun a bearing may be it was my tune mayve my engine builders fault I can't say for sure but you asked for input and that's mine
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Old Jul 3, 2018 | 09:37 AM
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But what I forgot to add was I changed to 317 heads dual methanol nozzles on on pump gas and 100% meth same setup I said before except I went with s476 turbo and I'm in the 22-26 psi range most of the time now and that's more hp than u want but it's reliable either way I would drive this **** box to cali race and drive home no worries
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Old Jul 3, 2018 | 10:01 AM
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Originally Posted by 30th t/a
Why go through the trouble of swapping heads if my goal is only 600rwhp
Why go through the trouble of forging the shortblock for only 600whp?

At some point, you're going to want more. 317s will allow that. So will meth. You're crutching yourself for no reason.
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Old Jul 3, 2018 | 10:13 AM
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Originally Posted by JoeNova
Why go through the trouble of forging the shortblock for only 600whp?

At some point, you're going to want more. 317s will allow that. So will meth. You're crutching yourself for no reason.
Because a stock LS1 shortblock on straight 93 on 10psi or more is a gamble. I dont care about how many guys are doing it. I wouldnt trust it. With my luck, id be that guy and melt a piston.
Id rather do it right the first time with a forged shortblock.

Meth might be in the future but 317s are not. That 1/2 point of less compression and a tad more flow isnt needed for my goal.
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Old Jul 3, 2018 | 10:24 AM
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Originally Posted by Dimeomboost
But what I forgot to add was I changed to 317 heads dual methanol nozzles on on pump gas and 100% meth same setup I said before except I went with s476 turbo and I'm in the 22-26 psi range most of the time now and that's more hp than u want but it's reliable either way I would drive this **** box to cali race and drive home no worries
Nice, thanks for the info!
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Old Jul 3, 2018 | 03:39 PM
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Why is it a gamble? Are you trying to run 22 degrees timing? Run 10 degrees and 16psi.

Grab a $700 methanol injection kit and install it. Problem over?
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Old Jul 3, 2018 | 04:37 PM
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Originally Posted by 30th t/a
Because a stock LS1 shortblock on straight 93 on 10psi or more is a gamble. I dont care about how many guys are doing it. I wouldnt trust it. With my luck, id be that guy and melt a piston.
Id rather do it right the first time with a forged shortblock.
.....
I used to think like this, and build a forged 383 to get my 600whp goal. Then I learned.

600whp is cake and doesnt require forged anything. Centifugal is even easier than a turbo. Keep the timing right and you should be fine for your goal.
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Old Jul 3, 2018 | 08:46 PM
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I ran mine without meth at like 700rwhp but didn’t go any further. 10.7:1 cr and 93 octane. I’ve gone way beyond that since with meth and e85.
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Old Jul 4, 2018 | 07:15 AM
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Originally Posted by Detoxx03
I ran mine without meth at like 700rwhp but didn’t go any further. 10.7:1 cr and 93 octane. I’ve gone way beyond that since with meth and e85.
Awesome man!
How much boost were you putting to that LS3 when you were just running straight 93?

I actually had a oem stock 6.2 that I was use in this build but after I installed it, found out the it only had 20psi of oil pressure. Got burned on the deal. Sold it as is and put that money toward the forged 347 I have now. Killer deal. Coukdnt pass it up.
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Old Jul 4, 2018 | 08:56 AM
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12psi on a all stock 5.3 no problem for a year. I did run a FMIC. And that was with a centri blower and the cheapest 93 pump in town.

Same engine custom blower cam, ported stock heads and 9-10psi due to better cam and ported heads and same blower and pulley. Switched to a meth kit on top of the FMIC spray a small amount of wiper fluid. No issues for a year.

Now the engine is the same and FMIC and meth with wiper fluid and I’m turbo’d and I’ve been to 14-15psi and drive it like I stole it with no issues. Is the meth needed? Prob not bc my IATs are only 20-30* above ambient with a $90 Ebay intercooler but it helps with the varying quality of pump gas.

I would run meth, you can get a pump and some nozzles for like $200 and be done, spraying wiper fluid will get you 100octane about and you’ll never pop the motor. It’s a small investment when your already spent big bucks on the forged shortblock which is not neccessary for 600rwhp. I’m close to that and my shortblock is untouched and has over 150k on it.
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Old Jul 4, 2018 | 04:22 PM
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Originally Posted by 30th t/a
Awesome man!
How much boost were you putting to that LS3 when you were just running straight 93?

I actually had a oem stock 6.2 that I was use in this build but after I installed it, found out the it only had 20psi of oil pressure. Got burned on the deal. Sold it as is and put that money toward the forged 347 I have now. Killer deal. Coukdnt pass it up.
I think at that time it was making either 10 or 12 psi
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Old Jul 5, 2018 | 12:02 PM
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Originally Posted by 30th t/a
Awesome man!
How much boost were you putting to that LS3 when you were just running straight 93?

I actually had a oem stock 6.2 that I was use in this build but after I installed it, found out the it only had 20psi of oil pressure. Got burned on the deal. Sold it as is and put that money toward the forged 347 I have now. Killer deal. Coukdnt pass it up.
20psi hot oil pressure at idle? If so thats not horrible. My 5.3 has 20psi hot oil pressure at idle and shoots to 40psi on the throttle and Its been boosted this way going on 4 years and it also has 150k+ on the short block.
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Old Jul 5, 2018 | 03:00 PM
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A lot of the vvt motors only run 20-25 @idle . They have a high volume pump .my LY6 is like that
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Old Jul 5, 2018 | 07:32 PM
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Originally Posted by customblackbird
20psi hot oil pressure at idle? If so thats not horrible. My 5.3 has 20psi hot oil pressure at idle and shoots to 40psi on the throttle and Its been boosted this way going on 4 years and it also has 150k+ on the short block.
20psi cold. I did everything I could think of to gt the oil pressure where it needed to be with no luck. The machine shop found that the crank was cut .010" and standard bearings installed.
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Old Jul 7, 2018 | 11:36 AM
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Happy seeing 10.5+ compression and 93 pump gas...gives me hope with 10.7+/- and meth is do-able (cheaper than new heads)
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