Posts by Bugzilla

Quote from TravAZ

I get it. I just like to poke at people that estimate power, especially when its that high. Most people don't hit their estimate on a dyno and to me it looks like an aggressive number for that setup at 9psi. Looking forward to seeing the dyno charts to see how close you are to your estimate.

To illustrate your point above, it will be cool to compare your chart to mine. Ill dyno my built motor at 9psi and then turn it up to 15psi. There are several different variables, but it still would be interesting to see the differences for those thinking of building a 2.4.

Poke away all you want. I dont care but I still say it makes 425hp at the crank. Have you ever seen another Ecotec rev to 8k and peak power around there? RPMs play a big role in the power considering HP is just a math equation based on TQ and RPM. Would you believe me if I said I built a carbureted 2.4L that did 300 whp @ 8800 rpms NA?

We can compare dyno charts all day. It would be cool to see. But at the same time, its a dyno. Every dyno reads different. With the click of a button, I can make the dyno say I make 500 whp. But either way, I will throw it on the dyno to get some numbers. It will be going on a Mustang dyno.

Quote from Slingrazor

A good example of the different built motors would be DDMs new cams.
Their SC with the smaller pulley is making 320 HP at 10.5 psi. With the new cams allowing the head to breath better the motor make around 385 HP at the same 10.5 psi.

Great example! I bet the one with cams also peaks power about 5-700 rpms higher. Do you know what the specs on those cams are? Dont see them on DDMs website. I would love to see them add in a ported head to the mix and post results.

Quote from TravAZ

Low compression at 9psi making around 375hp at the wheels?

I need some more education to understand how this works...

I'm hoping to run 15-16psi through my built 9.5 compression motor and make 400hp at the wheel. I guess ill see what the dyno shows when I get to that point.

Its not really how much boost you run that determines how much power you are going to make. You can have 2 engines (we will call them both 2.4Ls) that both make 400 whp but one does it at 9 psi and the other at 15 psi. The power band will be completely different between the engines. The one that makes 9 psi is actually more efficient. That is mostly due to the head / cams combo. If the head can flow more air in and out of the combustion chamber, then the turbo/supercharger isnt trying as hard to force air through it. Hence, the reason why less boost still makes the same power. At the end of the day, both engines flow the same amount of air, just in a different way and at a different RPM.

Another example.Think of boost like a pressure washer. Even though it makes 150 psi, you are flowing the water through a 1/8" hole. We will call that stock head and cams with lots of boost. Now take your average hose. It has about 15 psi behind it flowing through a 3/4" hole. This will be the low boost engine with a good flowing head. Take the pressure washer and stick it in a bucket for 30 seconds and spray away. Then do the same with the hose. Measure the difference and the hose will be the winner. Not because of how much psi it has behind it (cause the hose does have less psi), but its about the minimal restriction in front of it.

Thanks guys. More to come soon. Just did a photo shoot tonight! Ok so obviously the ecotec isnt powering a slingshot, but it still looks good!

Well its been a while since I have been on here. Not that it really matters. Anyways, I finally got my destroked 2.4L done and running. I had an eight month setback with JE so it took way longer then I wanted. So here is a quick run down of what I did.

- 2.4L Block
- Eagle H-beam rods for a 2.2L
- 2.2L crank (2007-08 is 58x)
- Custom JE pistons setup for 9.25:1 compression
- 2007 style 2.2L head CNC ported intake runners, exhaust runners and combustion chamber (same head as a 2.4L but without VVT. My ECU does not support VVT)
- Comp cams with adjustable cam gears #113400 The cams are for the 1st gen head and have been modified to work with the 2nd gen head
- Oversized Inconel intake and exhaust valves
- ZZP 82# valve springs
- LSJ supercharger modified to fit a LS1 throttle body without an adapter. 2.7" pulley making 9 psi
- ZZP Neutral balance shafts

So the big question, why make a 2.4L smaller? More RPMs, less bottom end power with a smoother powerband helps with traction. This thing turns 8000 rpms and is still pulling. The bad news is that the blower is maxed out with my combo. Cant get boost over 9 psi. So I have a feeling I will be swapping it out for a turbo soon (already have the turbo). I really was shooting for 15 psi. No dyno numbers yet since the build is still fresh but I am estimating around 425 hp at the flywheel. A turbo running more boost should get me over 500 hp at the crank with ease. When I get dyno numbers I will post them.

The good part of the video is at 2:30.

https://youtu.be/wJ2XGcMhgtA

@TravAZ - Sorry I thought you meant something along the lines of having physical turbo issues. Not boost issues at low rpm.

But having said that, throw a roots style blower on and see what happens! I get full boost around 2000 rpms...

Quote from JoeF.

I missed the part where anybody said this couldn't happen to a supercharged engine, it can, but your problem sounds like bad machine work that had nothing to do whether you had a turbo or super installed.

That is exactly my point. It was not the supercharger that caused my problem, it was machine work. I don't think it was Rabs turbo that cause his problem either. Was it something that was in the innercooler beforehand? Maybe some leftover sand from things getting blasted? Maybe it was a combination of an unknown pre existing engine problem and something getting sucked through the engine? Who knows... It could have been something to do with the turbo install but until the actual cause is found, its all a guess. What if it comes down to 2 innercooler pipes rubbing on each other inside one of the couplers? That wouldn't be a problem with the turbo kit or engine. Just install.

All I am saying is that Rab is in a bad spot. Stuff like this is very hard to pin point. I am not a person who points fingers and blames people. I find the reason why the issue happened and make sure it doesn't happen again. Live and learn. If it was an obvious issue and the builder/installer can admit to it, then they should be fixing it.

I am a little late on this thread but wanted to share something.

Some of you say this wont happen with a supercharger. Well it happened to me and I have a supercharger. A LSJ unit at that.

I had metal shaving run through my whole engine recently. My cause of death, valve springs. Lasted 365.3 miles. The place I had do the port work to my head failed to clearance the head for my bigger valve springs. I did not catch this on assembly since I really couldn't see where it was rubbing. After my engine started knocking, I pulled it out and tore it down. Couldn't find anything that caused the shavings (besides wasted bearings). So I started to tear my head down since it was the only thing left. Found the valve springs rubbing on the inside of the head. Bad enough to fill the motor with shavings... And to top that off, my guides were wasted (probably never replaced) and cause my beautiful oversized valves to hit the cylinder walls which also bent all my valves.

So Rab, sorry to hear about your loss. I know the feeling all too well. But in this industry, anything can happen. One little thing will cause a huge issue. Not pointing blame at anyone as your issue could have been from a number of different things.

This is all I see in your future....

You can always convert the Sling to a boat... Looks like the side by sides are doing it and 2 wheeled motorcycles

You are correct. But in order to do it the right way, you have to pull one bolt at a time. Do not pull all the head bolts and then put the studs in. Pull a bolt, put in a stud, and TQ in place. Then move on to the next one. Do it in the correct sequence as posted earlier by @Tripod.

Quote from Tripod

There are 10 bolts around the cylinders - those are 22 lb-ft; the 4 bolts at front of engine are 26 lb-ft. I'll come back with a pic for torque sequence...

Don't forget after you do the 22 lb-ft, you need to turn the bolt another 155°. Missing that step will cause all sorts of issues! Stock junk GM bolts only. I do the ARP studs to 75 lb-ft (in steps) even though ARP recommends more.

Yet another reason why I hate that GM loves using the angle TQ method on those bolts... ARP only for me on any build.

Thanks for the correction. Was at work and had LS brain going on. All ecotecs use the same length plug except the lsj which uses the shorter LS style plug. The TR series plugs will work in the lsj not the 2.4s. I believe it is the LTR series that would be the correct ones.

Quote from Dave@DDMWorks

Are you sure about that heat range on the LNF spark plugs? We have always been told that the stock LNF spark plugs after 2008 are a 5 heat range, NGK's site also crosses the 41-108 over as a heat range 5 - ILTR5C11, I have never seen them listed as a "7" heat range. Thanks!

I am pretty sure they are in the 7 heat range. I thought the 41-105 was the one in the 5 range. Physically looking at the 41-108 plug and comparing it to a NGK #7, they look almost identical.

@Dave@DDMWorks

I agree. I have not seen any detonation issues with the iridium plugs. I actually think they help with detonation. It is more of a spark plug heat range issue that will cause detonation to happen. (or just a bad tune)

Non iridium plugs that would be comparable are the NGK TR7 for boosted and the TR6 for NA applications. Some people even use the TR55 for NA applications. Not sure what the 4 digit part numbers are off the top of my head.

On mine I used a factory GM iridium tipped plugs. They are the one out of the LNF. 41-108. Same heat range as the NGK TR7IX. Stock gap which should be .043". Do not use the ones out of the LSJ as they are too long and will hit the piston!

@iNewton You have had a week. Where is our update on your findings?

My work is about 15 min north of Corona. I am sure you can swing by and check out all the off road stuff we have in the shop and see a few of the Ecotec builds we are doing. No Slingshots in the building at the moment....

That is not good at all! Never like seeing things like this. I can tell your pistons were a bit on the loose side but that really doesnt explain metal in the oil. They didnt lose enough metal to contaminate the oil. I know you said your valve springs were super close, do you see any rubbing signs? The metal came from something else and i bet that was where the noise was from.

Just listened to the video.... Not piston slap for sure. Sounds more like something with the timing chain. I would say pull the valve cover off and try to look down the front to see if the chain is still on the passengers side guide. There is a chance it is only halfway on the guide.

Its not the valve springs or pistons. I have the same compression, bigger springs, big cams and mine is as quiet as a stock engine. Although it does idle at 1100 rpms which could change things up.