Options for engine longevity

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mathews8pt

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I'm looking for opinions on what I should do to decrease the risk of an engine failure. Right now the truck makes a little over 800hp with a set of 64/71/14 & 80/96/1.32 compounds. Full boost is achieved around 2400 rpm, and I'm a little nervous about the torque it's making for the mostly stock bottom end. I know some guys make a lot more hp and don't have issues but I've seen some die early deaths around this hp level.

Bottom end is stock besides loosening PTW and ring gaps when I built it.

I was just thinking about doing a larger secondary to move the Useable power band up and drop torque numbers some. This truck is just a toy that gets ran at the track for fun and at dirt drags. I'd like to up power a little more this winter so I can run closer to 10.50s then the 11.0s it runs now.

Would you do anything to the bottom end(studs, etc) and/or swap turbos to move the powerband?


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Mines similar to yours, a little over 900hp, but I did use ARP main studs and rod bolts. And I did go with a little larger turbos so it wouldn't spool as quick. Main thing I did though, was use a higher stall converter. It's suppose to be 2500, but I think it's more like 2600-2700. The higher stall keeps the extreme load off the engine until the rpms rise. Not a sure thing you won't bend a rod, but it should help some.
 
jasonc said:
Drop the compression down.
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I'd rather not pull the head off if possible. I'm sure that would help it live though.

The turbo and TC would be easy. My TC might need refreshed after these last 2 years anyhow


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Going with more stall on the converter will get on boost earlier and then pull it down hard at lockup. My way of thinking is that will be even harder on it, may run quicker though.
 
I agree lockup is hard on stuff but a looser TC won't make boost come on earlier. I would also be running a larger turbo so that would move rpms up as well.

Drothgeb, what turbo are you running as a secondary?


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More stall does create more shock at lock-up, but that's usually happening above 3000rpm. Getting off the line is where I break driveline parts, gotta be hard on the rods too. So I went up in stall to avoid the 2000-2500 torque band on the launch.

It's 66/71/13
 
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73mm clipped turbine would flow more and kill some bottom end spool. Are you tempted to get the connecting rods polish&peened?
 
56cummins said:
73mm clipped turbine would flow more and kill some bottom end spool. Are you tempted to get the connecting rods polish&peened?
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Not really. The truck will likely never be over 1k hp. My Goal for next year is 10.50s and I can always cut some more weight. It's about 6200 right now.

Might try a 66 or 69mm sxe with a 73/.91 ar


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I was low 800s running a relatively quick spooling 62/80 combo and a 2100 stall for a couple of years, and the stock rods did fine. Just don't go overboard on timing.

Before you change the secondary, I'd think about a bigger primary.
 
You lucky bastards with your 4.72 rod stroke. Makes me wish I never got a 6.7
 
Drothgeb said:
I was low 800s running a relatively quick spooling 62/80 combo and a 2100 stall for a couple of years, and the stock rods did fine. Just don't go overboard on timing.



Before you change the secondary, I'd think about a bigger primary.
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What are you running for a primary now?

I think my 80 will make more power with more fuel but I like to try new things as well


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On my 5.9 commonrail I had an S361.5 over 595 compounds that made peak hp at 3700rpm and peak torque at 3000rpm. Hp was 1200 and torque was 1800. That bottom end had stock VP rods in it and a colt stage 2 cam. Performed flawlessly for me for the past two seasons. Tuning was what kept my bottom end together, I was making peak boost by 2500rpm, but we limited the fuel delivery until 2800rpm.


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khaoskustoms said:
On my 5.9 commonrail I had an S361.5 over 595 compounds that made peak hp at 3700rpm and peak torque at 3000rpm. Hp was 1200 and torque was 1800. That bottom end had stock VP rods in it and a colt stage 2 cam. Performed flawlessly for me for the past two seasons. Tuning was what kept my bottom end together, I was making peak boost by 2500rpm, but we limited the fuel delivery until 2800rpm.
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That's a big gap in charger size. How's the 361.5 holding up? What sized wastegate? Is it a very obvious secondary then primary hit?
 
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