Boost bolt ?

[pstillo]

Is there any problems in using a boost bolt which replaces a intake bolt for boost pressure. Will the gauge be just as accurate? Why would someone drill and tap the intake manifold when they could just replace a bolt? Also what is the torque spec for a intake bolt?

thanks Peter

 

[JARichard]

If you buy from Geno's they send you a nice piece of papersaying the following " do not torque over ?? lbs. This is the voice of experience" I thought it was funny myself. I installed my gauges this weekend and the boost bolt worked fine.

 

[RTuvell]

Originally posted by pstillo

Why would someone drill and tap the intake manifold when they could just replace a bolt?

thanks Peter

Here are a couple reasons:



1. Before the boost bolt there was drill and tap.



2. After invent of the boost bolt many still don't know about it.

 

[DLeno]

thats pretty much it! the boost bolt is great. In the interest of science and over analysis, note that use of the bolt acutally should be just a tad more accurate (and will theoretically read lower -- it measures pressure in the intake manifold, as upposed to the intake pipe). There is a pressure gradient from turbo, through all the hoses, intercooler, etc. such that the actual manifold pressure is the lowest point.



folks dont drill and tap the manifold itself -- they drill and tap that cast intake pipe, which is what, 12 inches or so upstream from the manifold.



12 ft lbs is the limit on the Genos bolt. Because it is a hollow drilled-out bolt, it does not have the same sheer strength. don't over tighten or you'll break it.



no install probs for me either, it is an elegant, simple solution. One surprise for me was that you can't get a 5/8 socket on the bolt if you choose one of the bolts close to the firewall, which I did. I had to hand tighten the bolt, and then put the torque wrench on the 1/4" NTP fitting that screws into it. same difference -- torque is torque so if you put 12 ft. lbs on the NPT fitting, you have 12 ft lbs on the bolt.



oh, and if you use one of the bolts on the firewall side of the intake pipe, be prepared to assume some interesting positions getting to everything . I used the one furthest from the radiator that I could, because I think the install looks better (and to me it does), but I paid for it in requried dexterity . Still, the install took me all of 5 minutes.



According to the Genos instructions there are three bolt locations you can use, and they are clearly indicated in a diagram.

 

[swexlin]

When we installed mine, we didn't use a torque wrench. Tightened it, but made sure not to overtighten, Scott (Proram) checked me.

 

[DGFoster]

Are you guys saying I wont need to drill and tap the manifold the install the pyro???

 

[RTuvell]

Originally posted by DGFoster

Are you guys saying I wont need to drill and tap the manifold the install the pyro???

The boost bolt deals only with the boost gauge, not the EGT gauge (pyrometer). As far as I know, no one has come-up with a way around the need to drill and tap for the pyrometer. Anyone?

 

[CRuth]

No, no way around drilling and for the pyrometer, but, why the heck couldn't cummins just do it for us and put a nice easy to remove pipe plug in there.



I know, its like wondering why the dealer didn't do the recall and tsb on my truck since it all came out months before they sold it to me.

 

[DGFoster]

I got confused,DUH.

 

[CTDCAL]

Man, I like being precise and all, but is it really necessary to go so far as to do a measured torque on something as simple as a boost bolt? All kidding aside, a very good mechanic friend (not a parts changer but a problem solver beyond belief) once told me an old time quote: " Tight's tight, but too tight's broke!" when it comes to torque on most things.



I tend to apply this theory to most things with the exception of engine/drivetrain internals and lug nuts when disc brakes are involved.

 

[Badunit]

With experience you don't need a torque wrench for most things. Without experience you end up with loose or broken bolts or stripped threads. I don't turn wrenches as much as I used to and don't have a good feel for the torque like I used to so I break out the torque wrench a lot these days just to be on the safe side.

 

[DLeno]

thats right. I didn't know what torque was used to install the stock bolt, or I would have tried to correlate to the feel of that bolt. And since the instructions were so cautionary I needed a stake in the ground. Especially since this is the first time I have ever installed a hollow bolt with reduced strength in place of a standard bolt.



If you don't have a torque wrench you can get a feel for 12 ft. lbs by lifting something that weighs 12 pounds. then place the center of your hand 1 foot away from from the socket wrench center axis and pull with the same strength you did when you lifted the 12 pounds. b

 

[rfoust]

Technically, shouldn't the hollowed out bolt be stronger due to the increased surface area. Or does that just apply to lateral movements and not torque. I wonder if they used a softer bolt like grade 5 or less to be able to drill or hollow it out. Just spouting the info I know from my rock buggy---it's why I made my tie rod and drag link out of pipe instead of solid rod.

 

[nickleinonen]

Why would someone drill and tap the intake manifold when they could just replace a bolt? Also what is the torque spec for a intake bolt?

drilling and tapping is free... not hard to do at all, no risk of breaking a boost bolt off in the manifold

 

[DLeno]

bolt strength: This is a simplification, but if we consider "transverse sheer stress" (twisting the bolt in two), a hollow bolt is weaker because it has less cross sectional area that is experiencing the sheer stress as a result of the external torque applied by the wrench.



I like the bolt because of the install appearance.

 

[RTuvell]

Not Free But Darn Cheap!

Originally posted by nickleinonen

drilling and tapping is free... not hard to do at all, no risk of breaking a boost bolt off in the manifold

I purchased my boost bolt for $7. 50 from Geno's!