LS3 install questions

[Alex]

I capitulated and ordered 10.9 and 12.9 bolts. Frrrg, I hate metric, nobody has a decebt stock of plated metric bolts other than in 8.8 (and i refuse to use black oxide, hate them)

 

[Grant S]

Alex I couldn't find plated metric bolts either so I used Stainless on my adapter plate and motor mounts and pretty much everything else so far.

 

[Doc Kaler]

Grant,

You probably already know but:

"It is a common misconception that stainless steel is stronger than regular steel. In fact, due to the low carbon content, stainless steel cannot be hardened. Therefore when compared with regular steel it is slightly stronger than an un-hardened (grade 2) steel fastener but significantly weaker than hardened steel fasteners. "

(taken from a fastener website)

 

[Fran Hall RCR]

I told him the same thing but less eloquently...

I just told him to remove the stainless fasteners, as stainless is for kitchen appliances and Harleys....

 

[Grant S]

Thank you gentleman I will change them out. I will look to your side of the border for the good ones, all we seem to have in the shops here are from recycled harley's and stove bolts made in china lol.
Metric fasteners are really hard to find here. As for my motor mounts they have built in studs and look stainless, but are more likely chrome plated ? as for the everything else I have used SS bolts on, were not critical and do not require much strength so I should be good.

 

[Alex]

Thank you gentleman I will change them out. I will look to your side of the border for the good ones, all we seem to have in the shops here are from recycled harley's and stove bolts made in china lol.
Metric fasteners are really hard to find here. As for my motor mounts they have built in studs and look stainless, but are more likely chrome plated ? as for the everything else I have used SS bolts on, were not critical and do not require much strength so I should be good.

I wouldn't use stainless bolts anywhere (other than at grounding points). They gall and are weak as shit .... for a minute I thought you were joking when you said you used stainless bolts on your engine mounts! :O

After much searching I figured if you don't want black oxide bolts, order from Fastenal. They have branches in Calgary and Edmonton (and all over). My bolts will be here on Wednesday.

 

[Grant S]

Ok I just checked the manufacture on the motor mounts and they are Stainless studs, hundreds sold with no negative feedback and no reported failures, so I will cross my fingers and see how they hold up, time will tell.
HMS Urethane Engine Mounts (Shorter Version) C5/C6/GTO/RX7
as for stainless fasteners being a bad choice ? I would disagree. We have used them for years on a lot of equipment, dump trucks and sander bodies and they take tons of abuse, so far nothing has fallen off them, but yes they are a one time use as they usually break before coming apart but sometimes thats a good thing.

 

[Mike]

For several dollars worth of bolts - why risk it.

http://www.mcmaster.com/#

http://www.aircraftspruce.com/menus/ha/index.html

http://www.fastenal.com/web/search/...tion&refine=~|categoryl1:"600000 Fasteners"|~

 

[bob d]

Alex, I burned a piston at the number 7 cylinder. I took it to the engine builder I am using now and he said this was a common problem with the LS7. He put on aftermarket fuel rail and rerouted the fuel lines. It made sense what he explained to me, the fuel rail comes in and Y's, the back cylinder will not get the same pressure as the rest of the cylinders since it is so far away from the Y and all the rest of the injectors are taking the fuel first, so when the pressure drops due to the high fuel consumption when you are letting it eat, then the back fuel injector is loosing pressure causing it to run lean. He routed the fuel lines into the end of the fuel rail went down one side, crossed over to the other fuel rail on the same end of the motor then down the other fuel rail. He put the regulator after this. This way the fuel runs into the motor and is regulated after it goes through the fuel rails. I don't know if the LS3 fuel rail is the same but it has worked for me for the change. You can see the pictures of this on my build thread. I think it gets more consistent fuel pressure to all the cylinders now.

 

[Alex]

Alex, I burned a piston at the number 7 cylinder. I took it to the engine builder I am using now and he said this was a common problem with the LS7. He put on aftermarket fuel rail and rerouted the fuel lines. It made sense what he explained to me, the fuel rail comes in and Y's, the back cylinder will not get the same pressure as the rest of the cylinders since it is so far away from the Y and all the rest of the injectors are taking the fuel first, so when the pressure drops due to the high fuel consumption when you are letting it eat, then the back fuel injector is loosing pressure causing it to run lean. He routed the fuel lines into the end of the fuel rail went down one side, crossed over to the other fuel rail on the same end of the motor then down the other fuel rail. He put the regulator after this. This way the fuel runs into the motor and is regulated after it goes through the fuel rails. I don't know if the LS3 fuel rail is the same but it has worked for me for the change. You can see the pictures of this on my build thread. I think it gets more consistent fuel pressure to all the cylinders now.

Yea, #7 is a known problem, but it's only a problem if you're really driving it hard. I won't be, so can be lazy and use the stock rails

 

[Alex]

Are you guys using the OEM flexplate bolts to bolt the flywheel on? There doesn't seem to be that many threads past the end of the flywheel (maybe 1/2'' of threads?)

I was searching around and ARP makes flywheel LS bolts, but they appear to be the same length.

I read an obscure post somewhere about how flywheel and flex plate bolts are different lengths, but according to GM they're the same part number so that can't be it.

 

[Alex]

Everybody I asked just re-used the supplied flexplate bolts, so since they're the same part number as flywheel bolts, good enough!

 

[John]

My days of extreme are done sadly ...... now I long for simplicity

When worlds collide! What did I miss???

 

[Alex]

When worlds collide! What did I miss???

I went back to work and got older

 

[Alex]

Question about the oil pressure sender location on the valley cover - I bought the Katech modified valley cover and their oil pressure relocation piece.

Turns out the 90* adapter doesn't fit with an LS3 (or at least mine) - I ground down the intake manifold's base as far as I dared (just slightly past the plastic webbing on the underside) and also ground down the oil pressure adapter until I broke through the metal (so it still wasn't enough)

So I gave up and just brought my valley plate to a machine shop, which welded the hole shut (so the valley cover is flush on the top and bottom). However, when I thought about this as I installed it I wondered something - now there is no hole on the bottom of the valley cover - will this cause a problem? Oil will come shooting up the hole in the block, but won't have any hole to go into. I'm wondering if it will blow out past the rubber seal on the gasket and leak where it shouldn't be leaking?

I have no idea if I'm making this up or if this is a signifigant concern, but say the valley cover just had a plate welded over the hole on the topside - the hole in the block would mate to the hole in the bottom of the valley cover, so oil would come up, hit the plate welded ontop of the valley cover and all would be good. But with no hole on the underside of the valley side the oil pounds at the bottom of the valley cover and leaks past the rubber seal on the gasket?

Valid thought, or am I over thinking this and it's okay?

 

[Ken Roberts]

The o ring seal on the valley cover gasket plate will hold the pressure easily. Think about it..... the oil pressure sensor is a dead end anyways, musc like what you have done now.

I used the Katech elbow. I had to grind the bottom of the LS3 intake and the top of the Katech elbow. Then I milled 1/8" off the valley cover for final clearance. The elbow now clears the bottom of the plastic intake by 1/8".

 

[Alex]

The o ring seal on the valley cover gasket plate will hold the pressure easily. Think about it..... the oil pressure sensor is a dead end anyways, musc like what you have done now.

I used the Katech elbow. I had to grind the bottom of the LS3 intake and the top of the Katech elbow. Then I milled 1/8" off the valley cover for final clearance. The elbow now clears the bottom of the plastic intake by 1/8".

That's what I was thinking, but I'm obsessive compulsive and, to me, everything is a fire hazard or engine failure waiting to happen, so I obsess about hte smallest of details that wouldn't make sense to anybody but me

that's weird that yours fit - I ground the bottom of my intake right to the base (the webbing is totally gone and it's just hte flat base) and I chopped into the elbow to the point where I made a hole in it (i.e., chopped too far) and I was nowhere near clearing. Weird - maybe if I milled off the valley cover also I would have had the room, but just from the intake and elbow modification it's impossible to get it to fit.

 

[Mike]

LS3 install questions