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redblockpowered converts from 240 to 940

The carnage:
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All 8 bent. Signs of coolant burning in #4, never smelled or noticed a loss of coolant but it was crusty.

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Pistons were fine. Could barely feel anything. Glad to see the crowns didn't look like the surface of the Moon being that this was the turbo car I learned to tune.

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#1
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#2
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#3
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#4

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The cam gear. This is the one a friend redrilled to have a few adjustable positions.

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The nose of the cam (dowel pin installed as part of field repair attempt)
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It's sort of smeared across the nose. I won't be running this V15 anymore but maybe someone else will.
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Other side for comparison.

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I was afflicted by terminal "while you're in there" disease and did a very mild amount of porting.
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And .040" came off the head. I measured the chambers at 49 cc. Should be 8.9:1 compression.

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No more roll pins. Never. An A cam that was hanging around comes in off the bench until I find whoever in Sweden grinds the biggest cams.

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And it all comes back together almost exactly a week later. Dad helped a lot (and I borrowed his car for the week).
 
As for what happened? I think the cam gear was overtorqued when I did the front cam seal the Friday before. I imagine that coupled with the lack of bevels for strain relief on the "adjusted" positions on my gear meant the roll pin cracked on reassembly and failed on startup.

I found the missing chunk of roll pin on top of the water pump during disassembly.

Failure mode was pretty odd. Was driving in traffic and noticed a very slow and progressive loss of power. It died while I was pulling into a mall parking spot, I took a brief walk assuming something had overheated perhaps (and not wanting to look too broken down) and it obviously had zero compression on restart. Did plenty of field repair type stuff (does the cam still turn? is the belt in time? crank sensor???) then called dad, we tried to retime it to limp it home to no avail. Thankfully a friend was around to steal his brother's truck and dad's trailer and stay up with me until like 3 AM (good friend, clearly) moving trailers around and delivering my dead car back home.
 
You sure it wasn’t under torqued? The roll pin is basically there for positioning during install. Once the cam gear is torqued the face friction between the gear and the cam is transitioning the drive torque. I’ve run roll pins on steep ramp +14mm cams with 110lbs of seat pressure.
 
I know the solid dowel can’t hurt, it just shouldn’t be holding that much of the load. Good reason for improvements though.

You could talk to Reine at Kyrk Motorsports for your big Swedish cam.
 
Do they do normal sized ones too? I was looking at AGAP stuff mostly, I think the 234-11.5 or whatever they call it seems like a good fit for this car. Looking for maybe a little more? But not too much more. Enem's V16 is maybe a little big and not very modern from what I've seen.

Also process improvement: found out while assembling this that it wasn't actually impossible to hit the torque spec without the cam holding tool like I thought. We had a nearly identical roll pin failure on the lemons car way back when too. I see your point though. It's like wheel nuts. The hub should be holding the load.
 
Do they do normal sized ones too? I was looking at AGAP stuff mostly, I think the 234-11.5 or whatever they call it seems like a good fit for this car. Looking for maybe a little more? But not too much more. Enem's V16 is maybe a little big and not very modern from what I've seen.

Also process improvement: found out while assembling this that it wasn't actually impossible to hit the torque spec without the cam holding tool like I thought. We had a nearly identical roll pin failure on the lemons car way back when too. I see your point though. It's like wheel nuts. The hub should be holding the load.

I'm not sure on Kyrk, but my impression is there's a wide variety and the option for "roll your own" if you can account for a ~30mm base circle custom grind. Kyrk basically specs profiles and they are produced by Axelsson.

When I was working with Erland Cox over the winter (hey I should update my thread) he had some opinions on AGAP cams; primarily that he changes the ramp "because his are too aggressive from constant acceleration to constant velocity". He also stated that the finish on AGAP cams is not as nice on what he gets from Kyrk. He also said for a cheap COTS part he likes the KLR T5 but that's a 12.9mm cam so a little bigger than an RSI stage 3.

You could drop Erland a line and ask for his 2c, he has been super generous with his input and time from my experience. I think we've traded like 150 emails in the past 8 months!
 
I think I'll give that a try, nothing is really sticking out to me as an obvious choice for this car and what I'm looking for is realistically pretty tame.
 
He also said for a cheap COTS part he likes the KLR T5 but that's a 12.9mm cam so a little bigger than an RSI stage 3.
Lol when the RSI Stage 3 is a small cam, and you're not wrong. The T5 will do about 180-200 crank NA HP on a stock valve head. Should work well with a turbo!
 
We've got a bunch of bottom-of-the-page-cam recommendations in here like it's some Mopar forum.

The roll pin failure is sucky, and like Cam said, we had it on the race car too. Common denominator was custom modified stock cam gear with roll pin, I think the answer lies in there somewhere.
 
Regarding the TiAL TD04HLA turbine wheel, i just stumbled upon a research paper from a Korean tech university. They were doing research for/with Hyundai where they compared the stock Inconel turbine wheel with the TiAL one. This was done on a 2.0 GDI engine with a TD04HL-19T turbo. There wasn't any real steady-state performance benefit, but the transient response was improved as expected. These graphs tell it all really:
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They also measured the weight of the complete rotating assembly:
- Inconel wheel: 202g (TD04HL)
- TiAL wheel: 149g (TD04HLA)
 
Regarding the TiAL TD04HLA turbine wheel, i just stumbled upon a research paper from a Korean tech university. They were doing research for/with Hyundai where they compared the stock Inconel turbine wheel with the TiAL one. This was done on a 2.0 GDI engine with a TD04HL-19T turbo. There wasn't any real steady-state performance benefit, but the transient response was improved as expected. These graphs tell it all really:
View attachment 22881
They also measured the weight of the complete rotating assembly:
- Inconel wheel: 202g (TD04HL)
- TiAL wheel: 149g (TD04HLA)
Very cool. What's up the with extra torque on the inconel wheel though?
 
I think I read this report. I think there was something to do with the shape of the blades or something like that. If it's the same test, there was some nuances about the differences that didn't come down to just weight, but the materials used also allowed/did not allow some changes to the overall design of the impeller. Maybe one had thicker blades? Dang I can't remember.
 
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