[L78toLT1]

Originally Posted by oldman

checked the ring gap on the 1st and 2nd compression rings on all pistons they spec between .010 and .011. Either I'm lucky or it is a myth of tight end gaps as low as .005. I am NOT saying .010 is a good gap for supercharged engines.

My pistons look great BTW..

http://blog.wiseco.com/everything-yo...about-ring-gap

This

My ring gaps measured around .010 as well. Pistons looked good as new after ~5k non-gentle miles at 568 whp

[Umbriel]

Which lifter is everyone going to from Johnson, the 2110, 2110R or 2116?

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[oldman]

2110, to be realistic with my sub .600 cam and gentle ramp profile, LS7 may be absolutely fine. I probably would go with 2116 is I had a bigger cam or even one of the axle oiling setups. at some point, the plastic tray is going to fail, at some point, you are going to need a roller rocker too. So instead of getting into the cubic $$$$ club, I just went with a lower lift cam and a gentle ramp. 30 HP here, 30 Hp there is no big deal on a street car since traction is not available. i.e. ain't going to make the car faster.

[Umbriel]

Originally Posted by oldman

2110, to be realistic with my sub .600 cam and gentle ramp profile, LS7 may be absolutely fine. I probably would go with 2116 is I had a bigger cam or even one of the axle oiling setups. at some point, the plastic tray is going to fail, at some point, you are going to need a roller rocker too. So instead of getting into the cubic $$$$ club, I just went with a lower lift cam and a gentle ramp. 30 HP here, 30 Hp there is no big deal on a street car since traction is not available. i.e. ain't going to make the car faster.

Yeah I'm trying to decide on spending $2000+ on pistons and rods and $600ish on new lifters or juts buying a forged short block.

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[oldman]

Texas Speed has a good one, so doe AMS racing. The balanced TxSpeed 416 looks mighty tempting too. About $3000 all in. For a centri, the 416 probably more useful, and worth more if you are going to sell it later sans supercharger. For a PD, there is more than enough torque so the less stress on the walls probably better (unless you are going to sleeve). Here I personally of the opinion the more power the engine can make with no boost, the better and the 416 falls in line with that reasoning, especially with centri or turbo for that matter.

[Umbriel]

Originally Posted by oldman

Texas Speed has a good one, so doe AMS racing. The balanced TxSpeed 416 looks mighty tempting too. About $3000 all in. For a centri, the 416 probably more useful, and worth more if you are going to sell it later sans supercharger. For a PD, there is more than enough torque so the less stress on the walls probably better (unless you are going to sleeve). Here I personally of the opinion the more power the engine can make with no boost, the better and the 416 falls in line with that reasoning, especially with centri or turbo for that matter.

Are you saying the Texas Speed short block is $3000 or the rotating assembly is $3000? If the short block is $3000 I'm buying one tomorrow.

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[Joshinator99]

Originally Posted by Umbriel

Are you saying the Texas Speed short block is $3000 or the rotating assembly is $3000? If the short block is $3000 I'm buying one tomorrow.

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Must have been a typo. Short block starts at $6K with stock crank.

[Umbriel]

Originally Posted by Joshinator99

Must have been a typo. Short block starts at $6K with stock crank.

That's what I was thinking.

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[oldman]

3000 is for the balanced rotating assembly,and bearings.... toss in your block. It is a really good deal. The only reason I did not go this route is the block mod for the cleevite mains on the thrust bearings. AFAIK the new bearings need no mods...

[Umbriel]

Originally Posted by oldman

3000 is for the balanced rotating assembly,and bearings.... toss in your block. It is a really good deal. The only reason I did not go this route is the block mod for the cleevite mains on the thrust bearings. AFAIK the new bearings need no mods...

Yeah after paying labor to put it in it would be about the same price as buying one already built. I know you so your own work but I am not in that position unfortunately.

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[Red Lightening]

I broke down my motor this winter to go forged, more power, more fuel. I ran a D1x pro charger with a 4" pulley typically at 10-11 lbs. Lt4 fuel system, e85 1-7/8 looks long tubes no cats, awe exhaust. With a safe tune was at 724 whp 645 torque. Hearing all the horror stories, I wanted to share mine. With this tune in, I put over 7,000 miles of mixed daily driving, dig and roll racing, the cylinder walls and Pistons looked near perfect. My tuner felt that I could an extra 50hp out of the previous set up prior to running low on fuel, (as well as anytime North of 750 your messing with fire, there are plenty out there that even push 800whp) but at 724 was more reliable tune as most tuners will tell you that low to mid 700's is the limit on e85 without some type of additional low side beyond the lt4 pump. It is my experience that the Pro Charger set up and E85 both led to lower intake/engine temps likely kept it safer as the car rarely ran over 200 degrees even on hot days. Either way rings were mostly all around .015, so maybe I was fortunate?? It certainly sounds like the odds were against many LT1 owners in holding up over 600whp, but not in my case. This is not a fluff story, but real data, real experience, real people, (haha not actors), with a very reputable tuner in Colorado who did all the tuning, on a Dyno Jet. Based on the cars performance when racing and what other cars achieve those numbers also appeared legit.

[oldman]

With a 4.5 pulley, built engine, cam, heads etc, LPE HP pump, LT4 injectors, 33% cam lobe it is getting very close to running out of fuel. IMO for a 4" pulley and 7200 RPM, you need to go with the Lingenfelter injectors 10.5 CR, my comments are E85. Boost will be about the same but the engine is going to be breathing so much better. Start your own build thread, that would be cool!

[wnta1ss]

Originally Posted by Red Lightening

I broke down my motor this winter to go forged, more power, more fuel. I ran a D1x pro charger with a 4" pulley typically at 10-11 lbs. Lt4 fuel system, e85 1-7/8 looks long tubes no cats, awe exhaust. With a safe tune was at 724 whp 645 torque. Hearing all the horror stories, I wanted to share mine. With this tune in, I put over 7,000 miles of mixed daily driving, dig and roll racing, the cylinder walls and Pistons looked near perfect. My tuner felt that I could an extra 50hp out of the previous set up prior to running low on fuel, (as well as anytime North of 750 your messing with fire, there are plenty out there that even push 800whp) but at 724 was more reliable tune as most tuners will tell you that low to mid 700's is the limit on e85 without some type of additional low side beyond the lt4 pump. It is my experience that the Pro Charger set up and E85 both led to lower intake/engine temps likely kept it safer as the car rarely ran over 200 degrees even on hot days. Either way rings were mostly all around .015, so maybe I was fortunate?? It certainly sounds like the odds were against many LT1 owners in holding up over 600whp, but not in my case. This is not a fluff story, but real data, real experience, real people, (haha not actors), with a very reputable tuner in Colorado who did all the tuning, on a Dyno Jet. Based on the cars performance when racing and what other cars achieve those numbers also appeared legit.

With .015 ring gaps, yes you were somewhat fortunate in that aspect. You say that your car made 724hp, but what was the dyno correction factor applied (like 1.15 or 1.20 or ???)? With you being in Colorado, my guess is that your actual horsepower was much lower than 724, and the observed/uncorrected figure is what we need to know to properly evaluate your experience with that car. High altitude means thinner air which means less horsepower.

[95 imp]

Originally Posted by wnta1ss

With .015 ring gaps, yes you were somewhat fortunate in that aspect. You say that your car made 724hp, but what was the dyno correction factor applied (like 1.15 or 1.20 or ???)? With you being in Colorado, my guess is that your actual horsepower was much lower than 724, and the observed/uncorrected figure is what we need to know to properly evaluate your experience with that car. High altitude means thinner air which means less horsepower.

All that high altitude stuff goes out the door with supercharging....
You might have to run a smaller pulley to make the same HP at altitude though...

Besides, it isn't the rings. The failure in the pics doesn't support that theory.

If it were the rings butting, there would be seize marks all over the cylinder walls since the rings ends came together and bound up on the walls causing the lands to crack.

It's a detonation failure. Oil in the cylinder, going lean at WOT, bad tune, low octane, etc, is what everyone should be more worried about.