NMB2 drive video with gauges

[Agnem]

Well guys I have to say, I don't care what his dyno numbers are or what he breaks next. NMB2 has done more to advance the "can do" attitude of the IDI than anyone since Flatlander. From the intake and exhaust setup to the better turbo and the smaller things, everything about this build has been positive. I think he may have even learned from the bashing he got here, that you have to document what you do and share it. Secrets only irritate people. And he seems to have done a much better job this time around. What I hope floats to the top after all this, especially now that he has started breaking it.... which is necessary to find the new upper limits of things... but I would hope a new known boost number and piston mod can come out of this. People will always be able to play with more fuel, more air and so forth externally to the engine. But the known internal engine mods are far more valuable, since it will save any future performance enthusiast time when trying to build upon a solid base. Many thanks to those who have been following this thread off of OB, and keeping us updated. If there is an opportunity to collect the known mods and put them in a solid article here, I'd like to post it in the tech articles, with full credit to NMB2 and my thanks.

 

[Black dawg]

I have not been around high boost related hg failures, but it seems odd to me that such a big part of the gasket was blown out.

 

[towcat]

I have not been around high boost related hg failures, but it seems odd to me that such a big part of the gasket was blown out.

where it blew is a common failure point for IDI head gaskets. "normally" you don't see this until 150k on the odo.

 

[typ4]

Lookmat my link to gasket, it is the first type, we need the second type.

Its a simple matter of avoiding extrusion.

 

[towcat]

Lookmat my link to gasket, it is the first type, we need the second type.

Its a simple matter of avoiding extrusion.

it's a known problem area due to the water jacket passing through. there's just not enough material for clamping down onto.

 

[Black dawg]

it's a known problem area due to the water jacket passing through. there's just not enough material for clamping down onto.

I wonder if some center punch marks would help hold it in place?

 

[typ4]

no

 

[wmoguy]

Well guys I have to say, I don't care what his dyno numbers are or what he breaks next. NMB2 has done more to advance the "can do" attitude of the IDI than anyone since Flatlander. From the intake and exhaust setup to the better turbo and the smaller things, everything about this build has been positive. I think he may have even learned from the bashing he got here, that you have to document what you do and share it. Secrets only irritate people. And he seems to have done a much better job this time around. What I hope floats to the top after all this, especially now that he has started breaking it.... which is necessary to find the new upper limits of things... but I would hope a new known boost number and piston mod can come out of this. People will always be able to play with more fuel, more air and so forth externally to the engine. But the known internal engine mods are far more valuable, since it will save any future performance enthusiast time when trying to build upon a solid base. Many thanks to those who have been following this thread off of OB, and keeping us updated. If there is an opportunity to collect the known mods and put them in a solid article here, I'd like to post it in the tech articles, with full credit to NMB2 and my thanks.

This is what I like about the members of this site. It takes a real man to compliment someone else, whom otherwise chose to publicly mock and belittle you and your products and own achievements. A man of honor can identify someone elses achievement, regardless of how said invidividual may have acted towards you or others wrongfully. Keep up the good work folks, this is what keeps the site at the top of it's game in terms of knowledge, and moreso, integrity and honor.

 

[88 Ford]

I broke in my studs doing that about 7 or 8 times for good measure. Still blew the head gasket out.

Did you torque them only to what ARP says or did you go a lil further?

 

[Diesel JD]

I've had awhile to think about this and I've heard of a few failures with ARP studs both here at OB and on a 5.7 GM diesel forum. Yes we know the ARP studs are good but it appears they can be rather temperamental. Then again it could just be the 38psi is far too much boost for a streetable IDI. I think if he keeps it below 30-ish it should be fine. Most of the improvements Justin has come up with will still be effective at much lower boost levels.

 

[gatorman21218]

So a good 7.3 can get 450 psi of compression. So what happens to the total compression when you add boost? would 1 psi of boost add 21.5 psi of compression? so at 38 psi of boost you would be running 1267 psi of just compression. plus a shot of diesel and its no question that something is going to give. I may be wrong here though on my math

 

[Diesel JD]

I imagine that boost does increase the dynamic compression ratio some. I was looking at the math on wikipedia and it looks out of my depth except for the easy stuff for static CR, Recall that NMB2 is down around 18:1 which isn't much more than a 7.3 PSD (17.6:1) and I think they can push 25-30 on stock bolts and much more with studs. It would be great to know what the weakest link is, or if it was one of those unusual ARP failures I mentioned. I've seen it bite some people that apparently did everything right, good torque wrench, clean surfaces etc.

 

[DeepRoots]

double posting is awesome!

 

[DeepRoots]

So we're saying that studding an engine is going to cause this kind of distortion? What should be done to prevent that? There are an awful lot of studded engines that have run for years on this forum without incident and even NMB2s builds which were overtorqued and pushed a lot harder than most of us would push an IDI haven't blown up. I know that doesn't mean it's ideal or right..but it has been done.

Hi JD!

 

[88 Ford]

The common rules of thumb is that for every 2psi of boost it increases dynamic by 1. So if you add 10psi it bumps compression to 21.5. This is just what I have read and is not an exact figure. It is just a generalization.