550 hp @ 22 psi wtf? On e85

NoviBlownGT

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What cams? CR doesnt look to be the limiting factory as far as your power numbers. Something else is going on here. Also could be a super stingy dyno, seen it happen before.
 

palanza7

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What cams? CR doesnt look to be the limiting factory as far as your power numbers. Something else is going on here. Also could be a super stingy dyno, seen it happen before.

So they should be stock cams with stock springs.. I bought take offs on here from another member.. but its not like I actually verified any of that, maybe he didnt know what he had? Too many unknowns.. maybe I should pull a cover off and measure the cams verify they are stock.
 

stkjock

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Maybe it's the Dyno?

Get a lull elsewhere before opening shit up?
 

palanza7

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Maybe it's the Dyno?

Get a lull elsewhere before opening shit up?

Yeah that seems like my best bet for now, going to try and pull at another shop and maybe he can also verify my boost gauge is accurate and hopefully screw in his AFR sensor to verify mine as well.

Who knows whats going on at this point.

I had an idea of putting a piston at top dead center and filling it with heavy motor oil through the spark plug and measuring the volume of the dish that way, its not going to be super accurate but it should be enough of an idea to tell whether u have a -11 or -18cc dish. Suck out the oil then burn the rest off.

Might also do a compression test to see if i can verify that the cams are running similarly .

Reallllly not trying to take a head off especially if that isn't the problem. No idea what else could be the restriction.. if the cam's weren't stock I'd assuming it would run like shit. Maybe the stroke was also wrong from MMR and I'm running at like a 7 CR.

Really sucks to spend over a year working on something expecting a 700 rwph number and be greeted with 550 LOL.
If the CR is super low then it comes down to which is cheaper.. rebuilding the engine with the correct pistons or selling the TVS and buying a much larger S/C lmao
 
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mrt2you

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i make 650 rwhp. .020 over 4.6, 10-1 compression, ported first design tvs 2300. DOB intake with the smallest upper pulley they make, 10% overdrive lower, 20lbs peak boost, stage 1 FRPP heads, detroit rocker cams, 72mm L&N throttle body, 123mm cai, 1 3/4 american racing long tubes. not sure what the timing is. but that's on pump gas.
numbers from a dynojet dyno.
 

palanza7

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i make 650 rwhp. .020 over 4.6, 10-1 compression, ported first design tvs 2300. DOB intake with the smallest upper pulley they make, 10% overdrive lower, 20lbs peak boost, stage 1 FRPP heads, detroit rocker cams, 72mm L&N throttle body, 123mm cai, 1 3/4 american racing long tubes. not sure what the timing is. but that's on pump gas.
numbers from a dynojet dyno.

Yeah that sounds about right. With running e85 and a crap load of timing I'd expect to be at least there as well even with lower compression than you.
 

46addict

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A ton of timing isn't always a good thing. Once you reach the point of diminishing returns, not only is it more knock prone, you start subtracting power. I would reserve any judgment until you get some track passes in on a day with decent density altitude, and then think about bumping compression if you come back with substandard trap speeds.

If you have stock cams, you would benefit from more lift, and it would be an easier job than increasing compression. Also, I don't know what the IAT threshold for timing retard is on E85 setups, but it may also be time to upgrade heat exchanger parts and/or hood upgrades for heat extraction if the IATs are on the borderline.
 
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weather man

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i make 650 rwhp. .020 over 4.6, 10-1 compression, ported first design tvs 2300. DOB intake with the smallest upper pulley they make, 10% overdrive lower, 20lbs peak boost, stage 1 FRPP heads, detroit rocker cams, 72mm L&N throttle body, 123mm cai, 1 3/4 american racing long tubes. not sure what the timing is. but that's on pump gas. numbers from a dynojet dyno.

Healthy for pump gas. On pump 91 (597 rwhp) I could not go more than 12 psi and/or 15 degrees of timing without knock.
 

palanza7

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Na with e85 heat soak defo not an issue. Going to try and investigate cams, maybe they were timed incorrectly when they built the engine.
 

BruceH

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What was the deck height of the pistons? I'm thinking you have a lot lower compression than you think you do.

Two things would result in significantly lower than expected compression and both result in the pistons being deep in the hole. My guess is that either the compression height for the pistons is wrong or the wrong connecting rods were used.

FYI deck height should be about -.008" in the hole with a 4.6.
 

palanza7

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What was the deck height of the pistons? I'm thinking you have a lot lower compression than you think you do.

Two things would result in significantly lower than expected compression and both result in the pistons being deep in the hole. My guess is that either the compression height for the pistons is wrong or the wrong connecting rods were used.

FYI deck height should be about -.008" in the hole with a 4.6.

Sigh I really hope that this isn't the case but of course it could be. You'd think I'd be able to tell when the cars off boost like that it would really struggle to get up and move but maybe I can't tell?

Deck height.. no idea. Being that this was my first engine being built I didn't have the experience to make sure they documented all the critical dimensions to reference all of this. At the end of the day I probably won't know any of that until I pull a head off. Which is going to be a real bummer. Can't really hold anyone accountable a year and a half later, but I will definitely be calling MMR and raising hell if they sent the wrong everything.
 
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BruceH

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Sigh I really hope that this isn't the case but of course it could be. You'd think I'd be able to tell when the cars off boost like that it would really struggle to get up and move but maybe I can't tell?

Deck height.. no idea. Being that this was my first engine being built I didn't have the experience to make sure they documented all the critical dimensions to reference all of this. At the end of the day I probably won't know any of that until I pull a head off. Which is going to be a real bummer. Can't really hold anyone accountable a year and a half later, but I will definitely be calling MMR and raising hell if they sent the wrong everything.

It's measuring the pistons at tdc. Distance from the top of the block (deck) to the top of the piston. On a stock 3v it's -.008". IIRC my current motor is around -.004" but it's been too long since I put it together to remember. I have it written down somewhere along with the bearing clearances, ptb, ring gaps, etc.

Measuring how far the pistons are in the hole at tdc is a qc step, it's the last thing to measure that will give an indication if something is out of spec.

It happens. A friend of mine had a shop put together his shortblock. He couldn't make more than about 550rwhp with a D1 procharger pushing over 22psi. Something was wrong. He tore the motor down himself and the pistons had a compression height of 1.150". They should of been 1.220". This meant the pistons were in the hole an extra .070" and the compression was super low.

Once he figured it out and contacted DSS (the company he got the pistons from) new pistons were sent out, the motor reassembled, and he ended up making around 670rwhp with pump gas and meth. Clocked off a 9.998 with that setup, a manual trans, and slicks. Only one time, the track got real upset.
 

BruceH

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I didn't pick up on the stock cams and springs until now. The stock springs could be blowing off that extra boost. Also, the stock cams will work with high boost but they aren't the best choice.

By any chance did you try it with a bigger pulley? If so what were the results with less boost?
 
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01yellerCobra

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What about the blower just not being able to keep up? One of the signs of an eaton being done is that it has a higher torque reading than horsepower. It can't keep up with the airflow on the top end.
 

BruceH

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FWIW I once had a similar setup but it was 9.4 compression, stock bore and stroke, Whipple at 16psi, comp 127300 cams and 26113 springs. It made 599rhwp on E85. Fastest trap speed was 127.
 

46addict

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Is there a sizeable difference in compression when the deck height is -.004 versus -.008? Using a calculator online that only netted a .09# change in compression.
 

BruceH

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Is there a sizeable difference in compression when the deck height is -.004 versus -.008? Using a calculator online that only netted a .09# change in compression.

Why do you ask? It's negligible just like the calculator showed. When building a motor you never know exactly what you will get, especially when the block is decked. Hence the measurement just to make sure.
 

palanza7

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Yeah there are definitely a lot of possible issues to consider here. I didn't think about the springs being an issue either. I do have a bigger pully that drops things down to 18 lbs, could give that a go just to see what happens but yeah, having a lower than what I thought CR would explain a lot of this.
 

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