911tt

I got the ATI crank pin drill fixture kit (PN 918993)


The install instructions are here:
http://www.atiracing.com/instructions/918993.pdf

I'm slightly confused because I was planning to install 2 pins, which the instructions also reference, but this kit has you drilling perpendicular to the center axis of the crank so that the pin can seat in the keyway. The instructions tell you to install a second pin 180 degrees to the first one, but there's no keyway to match it on the pulley.

Other kits have you drilling into the front face of the crank and pulley so that half of the pin is in the crank and the other half is in the pulley, i.e. this one:


So I'm assuming that to have two pins using the ATI kit I'd need to add a second keyway to the pulley.

Easiest path seems to be to just use a single pin in the ATI keyway, but there are some folks saying that the keyway is really meant for a key on the crankshaft and a pin will dig into the keyway over time and make the pulley difficult to uninstall in the future.

Thoughts?

RapidC84B

Use the single pin... 2 pins is only for high strain supercharged applications. Even then 2 pins is overkill. Yes the "normal" pin kids pin a crank from the front, but the ATI pin is creating a sort of crankshaft key for a crank not machined for a key which of course allows you to use the ATI hub's keyway.

Never ever had an issue removing an ATI hub, never seen any wear between the pin and hub keyway... like most crap in the internet, bad info.

911tt

Sounds like a plan, thanks!

I've got everything disassembled and the steering rack pushed out of the way but somehow managed to break one of the jaws on my puller tool trying to get the pulley off. Pretty sure I was doing something wrong. Waiting for new tool to arrive is giving me more time to clean up the mess in the engine bay, it is absolutely filthy.

I'm about 90% sure the crank seal is the source of my oil leak so I'm getting pretty excited to have everything back together. The big question is the camshaft, I'm hoping to be able to identify it without removing it. If I have to remove it then that creates a whole new set of steps.

RapidC84B

You can "rent" a pulley puller from any local auto parts store for free... they put a hold on a CC and take it off when you return it.

911tt

I got the factory harmonic balancer off, luckily there doesn't appear to be any damage to the crank snout.

Unfortunately there are no markings on the front of the cam, which means it will need to come all the way out for me to identify it. To take it out I'll need to remove the valve covers, lifters, and rods. I've got to say I'm tempted to not even bother but I feel like I've come this far and I might as well go the rest of the way. The car is already tuned for this cam so replacing it would require a new tune. It's already going to be a challenge for me to get everything back together properly and I'm worried about getting the cam and crank properly clocked and getting the lifters back on correctly.

Even though I'm not excited to tear even deeper into it, I do need to know what kind of cam I'm dealing with because I might want to replace it or at least know what the maintenance schedule for the springs is going to be.

Another aspect that's a little daunting is that I'm not 1000% sure the front crank seal was the oil leak culprit, although I'd say I'm 90% sure, especially considering that my harmonic balancer bolt had backed all the way out, which let the balancer come half-way off of the crank before it was stopped by the steering rack.

Notice this discoloration on the corners of the pan gasket where it meets the timing chain cover:


Is that normal? I would really hate to do all this work and find out I have a problem with the oil pan gasket. How perfect do I need to get those surfaces before I reassemble?

The bright side is that installing the DRM steering rack bushing was a piece of cake with everything taken apart.

I've also spent many hours degreasing / degriming various parts of the engine and engine bay. It's not perfect but it's a huge improvement.

RapidC84B

1. I wouldn't pull the cam just to find out the specs given the car is tuned for it. You can use dowels to hold the lifters up vs. pulling the heads... you have to pull the heads to pull the lifters. If you're going to do all that you may as well get a ton of new stuff.

2. That "discoloration" is RTV which is what you're supposed to do at the corners of the gasket where the timing cover meets the front of the pan.

Kubs

Why do you need to know what cam is in there? Is it not running the way you want? Not make enough power? Since you are just learning the car, dont change things like add power, or anything until you can fully drive what you already have.

Replace the crank seal, install the new timing chain, pump and balancer and put it back together.

911tt

I misspoke, I meant I would have to remove the lifters in order to get the rockers out of the way and get the dowel rods in there.

I'm talking about the brown stuff in the very corners, it looks like when they did the cam they used black RTV and it came off pretty easily. That brown stuff is a lot more stubborn and seems like it could make it harder to get a good seal. Again I'm not experienced enough to know how perfect I should be trying to get it.

I'm actually thinking about getting a milder cam. The idle is set at about 950 RPM which I assume is to keep it from stalling, it smells of raw fuel at startup, and it needs to be kept above 2K RPM at slow speed or it lugs pretty badly.

I don't really mind the drivability aspect of it and I'm happy with the power it makes. I'm concerned that it's too aggressive and may hurt the longevity of the engine or could require frequent spring replacement and I don't even know what springs to pair it with.

I'd love to start buttoning it up today instead of going any deeper.

RapidC84B

The brown stuff is the OEM RTV. Just get red high temp rtv and put a little on the corners there when you reinstall the timing cover.

911tt

Forgot to mention it appears to have a nearly new MEL-M295 oil pump in it. I guess I'll put my new one in just for peace of mind.

911tt

Ah, that makes sense.

RapidC84B

You should get a set of C5 shop manuals as deep as you're getting.... I'd sell you my set, but I'll probably end up with another C5 one day.

911tt

I picked up a copy of "How To Rebuild GM LS Series Engines" by Chris Werner but until this point I've been relying on the tutorial at ls1howto.com for the disassembly.

RapidC84B

I have that one too, but LS1howto.com taught me everything back in the day and gave me the confidence to tear into engines

Kubs

Sounds like you need a better tune for drivability. I have seen some pretty aggressive stuff drive on the street just fine.

911tt

Speaking of LS1howto.com, they indicate that you should run a bead of RTV around the entire base of the timing cover, is that the commonly accepted way to do it?

RapidC84B

Yeah that's not needed... I did that on my first C5Z and it didn't hurt anything, but if you look at your picture the pan already has a gasket there. The OEM FSMs only call for rtv at the corners.

911tt

OK the new plan is to leave the cam in and button her up. At some point I'll get a valve cover off to get a look at the springs and see if I can get any clues about a service schedule for them, but for now the goal is a car that doesn't leak oil and is ready for a track event in early June.

I ordered one of the SacCityCorvette AlignIt tools to make sure I get the cover perfectly centered on the crank and hopefully minimize chances of the seal leaking again any time soon. While I'm waiting for that to show up I'll continue cleaning up the engine compartment and maybe get around to finishing up the seat/harness install.

RapidC84B

Return it... your ATI pin fixture is a perfect alignment tool and a direct copy of a crank pulley hub.

911tt

In the process of getting it back together, realized the old pump was a Melling 10295, which is a high-pressure pump. That would explain why I was always seeing such high oil pressure. I'm installing a Melling 295, which is a stock replacement. I haven't done a lot of reading but there seems to be some risk of a high pressure pump causing problems.