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eschaider 11-19-2020 02:56 PM

The only way you can get away with 10 or 11:1 compression and a supercharger is very low boost and or timing. The detonation we all can hear occurs much later in the ignition event than incipient detonation.

Detonation in an n/a engine is tantamount to a tack hammer. Detonation in a blown gas engine is equivalent to using a short handled 5lb sledge hammer. Incipient detonation is undetectable by the human ear and falls somewhere between the carpet hammer and the 5lb sledge (but favors the sledge) and can do both impressive and considerable damage over time to pistons, blocks and heads.

This is what incipient detonation does to pistons over thousands of miles;

https://www.modularfords.com/attachm...0&d=1508175761

This engine did not smoke, felt responsive to the throttle but not surprisingly a little lazy. The thing that saved the throttle response was a PD blower. BTW notice how good the skirt looks. This was an example of a tuner (a big name one) who early on in his professional career subscribed to the mean is lean school of thought and produced tunes that felt very responsive to the throttl, until you put the engine under load. Then it was, well not so much ...

Over time, the slightly lean mixture, the occasional tank of not so good gas etc, etc slowly will eat away at the pistons. If this happens in an iron block you have the extra added attraction of ultimately cracking the block between the cylinders and/or down into the main webs.

In the end everyone is entitled to their own opinion about what is safe. The ultimate arbiter however is the engine. If it doesn't like what you are doing or how you are doing it, it will not matter what anyone says, thinks, or writes or who you are ... The incipient detonation will eventually catch up with the engine and cost someone a fair amount of cash to repair the damage.

The small amount (if any) of additional power obtained by engaging in an unscripted dance of death with detonation is vanishingly small compared to what the motor is capable of when built, fueled, and tuned correctly and safely.

There is no need to play Russian Roulette with a blown gas engine especially with more than one bullet in the gun.


Ed

joyridin' 11-19-2020 03:59 PM

Quote:

Originally Posted by eschaider (Post 1485485)
The only way you can get away with 10 or 11:1 compression and a supercharger is very low boost and or timing. The detonation we all can hear occurs much later in the ignition event than incipient detonation.

Detonation in an n/a engine is tantamount to a tack hammer. Detonation in a blown gas engine is equivalent to using a short handled 5lb sledge hammer. Incipient detonation is undetectable by the human ear and falls somewhere between the carpet hammer and the 5lb sledge (but favors the sledge) and can do both impressive and considerable damage over time to pistons, blocks and heads.

This is what incipient detonation does to pistons over thousands of miles;

https://www.modularfords.com/attachm...0&d=1508175761

This engine did not smoke, felt responsive to the throttle but not surprisingly a little lazy. The thing that saved the throttle response was a PD blower. BTW notice how good the skirt looks. This was an example of a tuner (a big name one) who early on in his professional career subscribed to the mean is lean school of thought and produced tunes that felt very responsive to the throttl, until you put the engine under load. Then it was, well not so much ...

Over time, the slightly lean mixture, the occasional tank of not so good gas etc, etc slowly will eat away at the pistons. If this happens in an iron block you have the extra added attraction of ultimately cracking the block between the cylinders and/or down into the main webs.

In the end everyone is entitled to their own opinion about what is safe. The ultimate arbiter however is the engine. If it doesn't like what you are doing or how you are doing it, it will not matter what anyone says, thinks, or writes or who you are ... The incipient detonation will eventually catch up with the engine and cost someone a fair amount of cash to repair the damage.

The small amount (if any) of additional power obtained by engaging in an unscripted dance of death with detonation is vanishingly small compared to what the motor is capable of when built, fueled, and tuned correctly and safely.

There is no need to play Russian Roulette with a blown gas engine especially with more than one bullet in the gun.


Ed

Sure. That is why about 90% of all the supercharged/turbocharged LS engines are running boost with almost 11:1 and greater. Because it doesn't work. Looks more like the tuner doesn't know how to tune the engine properly.

As i stated, 8-9 psi is easily obtainable without the need for water/meth injection. Thousands upon thousands of people are doing it in daily drivers with no issues and have a lot of miles on their cars already.

eschaider 11-19-2020 06:37 PM

You are missing the point here. I am not attempting to convert you to anything. I am offering you information you might find useful. If you want to boost your engine to what ever manifold pressure you like, I think you should absolutely do that. It's your engine, your parts, your money and most importantly your rules. Definitely go for what ever you think is best for your personal situation.

You should also remember a turbo does not hit the engine as hard on the bottom but hits it much harder on the top and of course you can't hear incipient detonation at lower engine speeds so you definitely can not hear it at higher speeds.

Like the song says, 'don't worry be happy".


Ed

incoming 12-02-2020 05:15 PM

When I first saw this, I was thinking 7.3 Powerstroke? I think that would be kind of interesting?

spdbrake 12-06-2020 07:33 AM

Some new info on what is in development and and a tease on the Megazilla in development.

https://www.autoblog.com/2020/12/04/...e-godzilla-v8/

joyridin' 12-06-2020 07:54 AM

Quote:

Originally Posted by eschaider (Post 1485494)
You are missing the point here. I am not attempting to convert you to anything. I am offering you information you might find useful. If you want to boost your engine to what ever manifold pressure you like, I think you should absolutely do that. It's your engine, your parts, your money and most importantly your rules. Definitely go for what ever you think is best for your personal situation.

You should also remember a turbo does not hit the engine as hard on the bottom but hits it much harder on the top and of course you can't hear incipient detonation at lower engine speeds so you definitely can not hear it at higher speeds.

Like the song says, 'don't worry be happy".


Ed

You probably want to read that article spdbrake just posted and click on the Hennessey's 800 hp Venom 800. 12:1 compression and they are running 8 psi of boost with a supercharger. Do a bit more digging and you will see they are plopping superchargers on the GT350 with a flat plane crank and 12:1. The days of running 8:1 CR on a supercharger engine are pretty much past history unless you are building a 1960's engine.

eschaider 12-06-2020 11:57 AM

Like the song says, "don't worry, be happy".

If it's your money, your parts then its your call. Once you start to supercharge 8psi will get old very fast and you will begin to increase boost. Shortly after that bad things will begin to happen.

There is a reason some manufacturers can successfully use 12:1 and 8 psi of boost. Most high octane gas can handle an effective c/r in the neighborhood of 11 or 12:1 even somewhat higher for a short periods of time. It is possible to get away with an effective or if you will operating compression ratio of 15:1 and with race fuels as high as 17:1. Pump gas at usually 93 octane or in some places as low as 91 octane is looking more like a 12:1 c/r limit for very short periods of time

When you boost an engine you raise the effective (or dynamic) c/r by the number of additional atmospheres you add to the intake. At 8 psi you are adding 8/14.7 or 0.54 additional atmospheres. A 0.54 atmosphere increase in manifold pressure means you increase the unmodified effective compression by 1.54 times. That makes a 12:1 compression ratio looks like 18,5:1 compression.

You can not run pump gas at 18:1 compression and MBT (maximum brake-torque timing) without killing parts in any production engines.

In the case of the Coyote, Ford has several tools they use to mitigate the detonation potential at these thresholds. The ECU will take two steps to prevent detonation. The first will involve stretching out the intake valve closing point with the variable cam timing the way a long duration cam would do. By stretching out the intake valve closing point the engine's dynamic (read effective) compression is dramatically decreased. Unboosted or lightly boosted you still have a very responsive high compression essentially n/a engine.

In addition to the delayed intake valve closing point the ECU begins to pull timing until it can no longer "hear" the detonation. The effect is to produce a lower compression, detonation free but still supercharged (at low boost) engine with better than n/a performance. The other manufacturers who offer high compression lightly supercharged engines take very similar steps to protect the engine and manage warranty exposure / expense.

When you buy a supercharged Coyote crate motor directly from Ford it comes with 9.5:1 compression not 12:1 and has a Ford ECU with the VCT logic to stretch the intake valve closing point and the knock detection to pull timing at the first sign of detonation. Even the Edlebrock supercharged Coyote's on the Ford website come the same way with 9.5:1 compression.

Encouraging someone to build a 12:1 supercharged engine is sending someone down an expensive path of broken parts they do not deserve to experience. There are guys on this site who may want to experiment with supercharging and they do not deserve to be steered into destructive engine combinations.


Ed

spdbrake 12-06-2020 01:00 PM

The 7.3 is an amazing motor.

This video shows some of the items already or coming soon in the way of internals.
https://www.youtube.com/watch?v=OKAl...re=emb_rel_end

This video has the dyno runs on the Boosted build 7.3 with 12.5cr Wiseco pistons but actually run without the blower as a warmup / teardown baseline. I want to see the boosted numbers....
https://www.youtube.com/watch?v=mHTXBRRzo-s

eschaider 12-06-2020 11:15 PM

Quote:

Originally Posted by spdbrake (Post 1486087)
The 7.3 is an amazing motor. ...

This video has the dyno runs on the Boosted build 7.3 with 12.5cr Wiseco pistons but actually run without the blower as a warmup / teardown baseline. I want to see the boosted numbers....
https://www.youtube.com/watch?v=mHTXBRRzo-s


My bet is they will drop the compression and run about 1 atmosphere of boost (~15 psi). I believe the Whipple gizmo has a built in intercooler so I would expect the numbers to be double the n/a numbers.


Ed

Gaz64 12-07-2020 12:59 AM

Quote:

Originally Posted by eschaider (Post 1486115)
My bet is they will drop the compression and run about 1 atmosphere of boost (~15 psi). I believe the Whipple gizmo has a built in intercooler so I would expect the numbers to be double the n/a numbers.


Ed

I can't see how you would get double, if dropping the CR down to start with, to allow 1 bar of boost.

780hp on 12.5:1, so 1560hp on 10.5:1 with 15 psi?

eschaider 12-07-2020 02:06 AM

Here is the rationale behind my guess Gary.

To make 100 HP it takes 10 lbs of air per minute or 600 lbs/hr depending on the scale you wish to use. The 7.3L Godzilla displaces 445 cubic inches. At 7600 rpm assuming 100% volumetric efficiency the engine should make a corrected (to STP) 730 HP because it processes 73.0 lbs of air per minute at that rpm and 100% Ve. If you give it and additional 8% for ram tuning you have the 789 HP figure.

The 789 number is probably a result of the short runners tuning at the elevated rpm and enhancing the Ve number because of the ram effect. The video did not say if the power numbers were corrected nor which SAE standard was used for the correction (SAE J1349 or SAE J607) — assuming they were corrected.

J1349 corrects to a temperature of 77˚F and a barometer of 29.31 in Hg. J607 corrects to STP, 60˚F AND 29.92 in Hg. The J607 correction will yield 4% more power than the J1349 correction because of the cooler temperature and higher barometer.

When you boost the engine to 2 atmospheres (~15 psi) you increase the volumetric efficiency by essentially 100%, which should put the power at ~1460 rather than 1580. The reason for the reduction would be the loss of ram tuning in the blower manifold vs the very nice n/a manifold. If the intercooler does its job, you should see the doubling. If the intercooler is really good you can get a little bonus like the ram tubes on the n/a manifold provided but for a different reason.

That's the essential logic behind my guess at the likely power level the engine will produce. One piece that is missing is the power to drive the blower. The new 3.0L Whipples have a new rotor profile that produces a substantial reduction in IAT2 temps (post compressor charge temperature) along with a substantial reduction in the power the compressor consumes compared to earlier designs.

The whisper/guess numbers I have seen on two different cars running the new 3.0L Whipple compressor are 75 to 85 hp to drive the blower. That means whatever the dyno shows the blower has already siphoned off some of that power to supercharge the engine.

The other unknown is the efficiency of the intercooler. The inverted blower positioning and the larger, dual (I believe) intercoolers (one for each cylinder bank) are capable of significantly dropping IAT2 temps to essentially ambient or cooler especially with unlimited cool water in a dyno room. That kind of IC performance can significantly boost indicated hp.

I am quite interested in seeing what the engine actually produces. I find a lot to like in this new Ford engine — especially with a PD blower.


Ed

Gaz64 12-07-2020 03:54 PM

Hi Ed,

I like your thinking, and I enjoy reading your posts.

If, under boost, (15 psi in this case), we could double the air packed into the cylinder before the intake valve closes, then we "could make" double the power.

But with 12.5:1 compression, would you then think it would detonate itself to bits? Or the ignition timing has to retarded so much that the compression increase is hardly worth anything?

Note that they are running .900 valve lift, since the heads are the restriction to power.

Considering it makes nearly 800 on 12.5:1, I would be happy 1000hp on 9.5-10:1 on 15 psi for a street car. Imagine the manners, something your wife or good friends could drive with 5 psi.

Gary

eschaider 12-07-2020 08:45 PM

Quote:

Originally Posted by Gaz64 (Post 1486151)
Hi Ed,

I like your thinking, and I enjoy reading your posts.

If, under boost, (15 psi in this case), we could double the air packed into the cylinder before the intake valve closes, then we "could make" double the power.

But with 12.5:1 compression, would you then think it would detonate itself to bits? Or the ignition timing has to retarded so much that the compression increase is hardly worth anything?

Note that they are running .900 valve lift, since the heads are the restriction to power.

Considering it makes nearly 800 on 12.5:1, I would be happy 1000hp on 9.5-10:1 on 15 psi for a street car. Imagine the manners, something your wife or good friends could drive with 5 psi.

Gary


Thanks for the kind words, Gary. I could be wrong but I don't think I am when I say they will have to drop the compression and pull timing if they run any significant boost over the 8 psi number. At 8 psi (1.5 Bar or 1.5 atmospheres) the 12.5:1 compression will look like ~18:1 compression unless they stretch out the intake valve closing point.

Without reduced timing, an 18:1 c/r even for brief periods of time will severely detonate on 93 octane, It is possible to both stretch out the closing point on the intake cam and also drop the timing to likely be able to reach a detonation free space for say 2 seconds or so in the middle and upper rpm but the compromised timing will cost some horsepower down lower but still possibly put a big number up top.

My instincts say go to an 8.5:1 c/r run 2 BAR of manifold pressure, reasonable timing (very small retard), no delay or a very small delay in intake valve closing point and you should get pretty impressive numbers across the board.

The normal decrease in low speed throttle response and engine torque and an 8.5:1 c/r with a PD blower will be all but unnoticeable. With the immediate boost availability the PD design provides, the 8.5:1 c/r will immediately look like 17:1 compression. That's the good news. The bad news is the 93 octane has as much trouble with the 17:1 c/r as it has with the 18+: 1 c/r and it will most likely require some sort of crutching in the intake valve closing position and also the ignition timing.

I think it might be possible to soften the rate at which the timing comes in and also delay the intake valve closing on a decay style curve where the higher in the engine speed you go the greater the ignition timing and earlier the intake valve closing. this is the kind of stuff the ICE engineers and their first cousins down in the dyno cells are really good at noodling out — guys like us take more time and sometimes use a couple of parts up to get to the same or similar space.

I think the Godzilla may be the biggest bang for the buck (power-wise) in the entire Ford engine line up today. I really am interested in this next build phase they intend to put the engine through. I hope they are clear about things like c/r, timing and boost. Great engine at a very opportune time, love to see it with an aluminum block and heads.


Ed


p.s. Almost forgot. Your observation about the 0.900 lift cam could not be more on target. It is possible with the PD blower they might be able to soften the cam profile a whisker or so providing similar power potential while improving reliability.

FredG 01-19-2021 08:06 PM

Tooling around on You Tube I came across this video on the Godzilla engine.
https://www.youtube.com/watch?v=OUXFzpbVyjY

eschaider 01-20-2021 02:08 AM

Quote:

Originally Posted by eschaider (Post 1486119)
Here is the rationale behind my guess Gary.

To make 100 HP it takes 10 lbs of air per minute or 600 lbs/hr depending on the scale you wish to use. The 7.3L Godzilla displaces 445 cubic inches. At 7600 rpm assuming 100% volumetric efficiency the engine should make a corrected (to STP) 730 HP because it processes 73.0 lbs of air per minute at that rpm and 100% Ve. If you give it and additional 8% for ram tuning you have the 789 HP figure.

The 789 number is probably a result of the short runners tuning at the elevated rpm and enhancing the Ve number because of the ram effect. The video did not say if the power numbers were corrected nor which SAE standard was used for the correction (SAE J1349 or SAE J607) assuming they were corrected.

J1349 corrects to a temperature of 77˚F and a barometer of 29.31 in Hg. J607 corrects to STP, 60˚F AND 29.92 in Hg. The J607 correction will yield 4% more power than the J1349 correction because of the cooler temperature and higher barometer.

When you boost the engine to 2 atmospheres (~15 psi) you increase the volumetric efficiency by essentially 100%, which should put the power at ~1460 rather than 1580. The reason for the reduction would be the loss of ram tuning in the blower manifold vs the very nice n/a manifold. If the intercooler does its job, you should see the doubling. If the intercooler is really good you can get a little bonus like the ram tubes on the n/a manifold provided but for a different reason.

That's the essential logic behind my guess at the likely power level the engine will produce. One piece that is missing is the power to drive the blower. The new 3.0L Whipples have a new rotor profile that produces a substantial reduction in IAT2 temps (post compressor charge temperature) along with a substantial reduction in the power the compressor consumes compared to earlier designs.

The whisper/guess numbers I have seen on two different cars running the new 3.0L Whipple compressor are 75 to 85 hp to drive the blower. That means whatever the dyno shows the blower has already siphoned off some of that power to supercharge the engine.

The other unknown is the efficiency of the intercooler. The inverted blower positioning and the larger, dual (I believe) intercoolers (one for each cylinder bank) are capable of significantly dropping IAT2 temps to essentially ambient or cooler especially with unlimited cool water in a dyno room. That kind of IC performance can significantly boost indicated hp.

I am quite interested in seeing what the engine actually produces. I find a lot to like in this new Ford engine especially with a PD blower.


Ed


Here is their next video with the engine supercharged. Click here => Supercharged Godzilla The dyno measured 1450 HP @7000 rpm which is a whisker down from the 7800 rpm number they used for the n/a version of the engine.

The boost was 2 BAR (2 atmospheres) which should have doubled the power. If you can produce 790 @ 7800 a linear reduction to 7000 would be about 710 HP @ 7000 rpm. Double the mass airflow and you double the power which calls for 1420 HP @ 7000 rpm. The dyno showed 1450 HP. The difference was close enough it is likely atmospheric differences. Additionally at 1450 HP the dyno's margin of error could easily be 15 to 20 Hp. Quite impressive!

I was a bit disappointed when he was asked about compression and he deftly avoided speaking to the actual number he used. I would bet dollars to donuts he reduced the compression from the n/a 12:1 number in the previous test. My guess is he is right around 9:1 which would make sense at that boost level even intercooled.

All things considered, a very impressive engine!


Ed

joyridin' 01-20-2021 06:31 AM

He makes a comment about running 12.5:1 pistons, but then said the heads are massively reworked. He also stated he ran on BP gasoline, but if you look at the top of the dyno chart, it says C16 fuel, which I believe is about 117 octane. Hardly any type of pump gas. Everything you are seeing is reasonably common in LS engines, except they are all running E85 or even E100.

With that gas, what he is running is feasible. It will be interesting to see what happens when he increases the boost though.

Anthony 01-20-2021 07:34 AM

cool engine build !!!

he stated the engine was built to be a blower motor, with appropriate heads, cam, compression (12.5), and made 790 HP. he thought that if he were to built it to be a NA engine, with ? 16:1 compression, different heads, cam, and dry sump, vacuum pump, bigger throttle body, it would make closer to 900 HP.

when he installed the supercharger, he also installed a dry sump , and ran the boost at 16.5 psi. he never mentioned the difference in air supply temperature.

eschaider 01-20-2021 10:43 AM

Quote:

Originally Posted by joyridin' (Post 1487895)
He makes a comment about running 12.5:1 pistons, but then said the heads are massively reworked. He also stated he ran on BP gasoline, but if you look at the top of the dyno chart, it says C16 fuel, which I believe is about 117 octane. Hardly any type of pump gas. Everything you are seeing is reasonably common in LS engines, except they are all running E85 or even E100.

With that gas, what he is running is feasible. It will be interesting to see what happens when he increases the boost though.


He was sufficiently non-specific in his commentary that it was not clear whether or not the c/r comments were specific to the n/a or boosted engine. He also completely avoided answering the question at the end of the video when he was directly asked.

I think we need a clear answer. That said, I'll still bet dollars to donuts it is down in the 9:1 area.


Ed

eschaider 01-20-2021 10:57 AM

Quote:

Originally Posted by Anthony (Post 1487897)
cool engine build !!!

he stated the engine was built to be a blower motor, with appropriate heads, cam, compression (12.5), and made 790 HP. he thought that if he were to built it to be a NA engine, with ? 16:1 compression, different heads, cam, and dry sump, vacuum pump, bigger throttle body, it would make closer to 900 HP.

when he installed the supercharger, he also installed a dry sump , and ran the boost at 16.5 psi. he never mentioned the difference in air supply temperature.

In the n/a video he actually did say it was built to be supercharged and at that time it was sporting 12:1 c/r pistons. Again, his ambiguity and decision to avoid answering the c/r question in the second video with the supercharged engine makes what he actually used in the blown engine build difficult to determine, at best. I suspect with a little more time (and vids) the answer will become clear. My bet is still on the reduced compression number.


Ed


p.s. We have often heard the old saw that an engine is just an air pump. In fact that is why cams and head selections carry the significance they do. We are attempting to optimize the pumping efficiency of the engine. the short block is only about reliability.

As luck would have it it takes 10lbs of air to produce 100 horsepower. The interesting thing is it is fairly constant across fuel choices, i.e. gas, methanol, ethanol but not nitro — because nitro is a monopropellant.

Once we achieve a 100% Ve the only way (with out boosting) to increase power is ram tuning of the intake which tends to be rpm specific and not a uniform increase across the operating rpm band. So where does c/r fit into the picture?

Remember when we were kids and got out contraband fireworks for the 4th or July? We all had some with fuses that never lit the firecracker. When we cut them open and ignited the gun powder with a match it just burned with a flash. The event was sort of like the photographers before flashbulbs were invented — just a flash, lots of smoke and light.

Well take that same gunpowder and wrap it tightly in its firecracker paper and external shell and it wouldn't burn it would go bang! Same thing with fuels. If you pour gas on the ground and light it, it burns with a yellow flame but not explosions. Put the same fuel in a hot cylinder, start compressing it and ignite it 30 or 35 degrees before TDC and you have a controlled but very fast burn. The pressure of the burning gases peaks, pressure-wise, somewhere around 7 to 10 degrees or so ATDC, pushing the piston down with a lot of gusto.

If you run too much timing the in cylinder pressure rise is too steep (quick) and the mixture literally explodes at or very near TDC creating the engine killing knocking sound we all recognize and try to avoid. Increasing octane slows down the burn rate and allows a wider window in crank degrees for the burning mixture's pressure to work on the piston.

A Internal Combustion Engineer (ICE) tries to engineer his engine design metrics and ignition curve for the most commonly available fuels to produce the advertised horsepower target. He does this by manipulating the in chamber rate of burn (measured in feet per second).

Once you have fit the completition of the burn event into that 7 to 10 crank degree window ATDC you have not only done all you can for that charge but it has provided all it can for engine power production. If, for example, you were to increase c/r for this event in this engine there would be no increase in power.

Why, you say. Well you have already previously converted all the fuel and air through their normal oxidation (burning) process into pressure energy. There is no more fuel to convert therefore no more power to be made.

Yes but, you say, all we need to do is add more fuel to fix that problem. Well, yes and no. If you just add more fuel the engine will go rich and get lazy. Well what about more air? Sort of late to the dance there also. The engine is already at 100% Ve, there is no more air to be had w/o supercharging.

in general when you play with gasoline your optimum if not maximum c/r is right around 17:1, if you have the octane to support it. When you have a 12:1 c/r you can safely boost the engine by about BAR (atmosphere). When you multiply 12 by 1.5 BAR (1 BAR is ambient) you get an effective c/r 18:1 — well dang don't that just beat all!

How about my engine 8.8:1 c/r with 2 BAR (atmospheres) of boost and an effective compression ratio of 17.6:1! Well dang! Don't that just beat all, again.

For gasoline and short bursts of performance your threshold max target operating compression is essentially 17 or 18 to 1. Higher and you detonate, lower and you leave power on the table. Other fuels have higher target compression ratios associated with their autoignition and critical points.

The 10 lbs of air per 100 horsepower is an excellent rule of thumb to tell you when you have gotten all there is to get for a particular mass flow of air. At that point fiddling with timing or c/r will bring no benefits to the table. If you want more power you need to process more air — it's really that simple. The rest of the dials will have no effect until you process more air. That means either a bigger engine, higher engine speed or a supercharger.


Ed

joyridin' 01-20-2021 03:22 PM

Quote:

Originally Posted by eschaider (Post 1487908)
He was sufficiently non-specific in his commentary that it was not clear whether or not the c/r comments were specific to the n/a or boosted engine. He also completely avoided answering the question at the end of the video when he was directly asked.

I think we need a clear answer. That said, I'll still bet dollars to donuts it is down in the 9:1 area.


Ed

It is higher than 9:1. I think 12.5:1 is not realistic either, but 10.5:1 or even 11:1 with what he has is very realistic. He said he had 12.5:1 pistons, but did not actually say the cr was 12.5:1. I doubt if he could massage those "factory castings" (head) as he states a few times, to get the cr down to 9:1. They don't have enough material on them. If he cranks that blower to 22 psi, he better start mixing that C16 with Nitro. Guys are running what he has in LS engines right now getting about the same HP if not more, but they have about a zillion intake/cam/head options.


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