SlowC7

NOTE: This How-To guide is neither endorsed by or property of Corvette Forum or myself in any way/shape/form. All liability stemming from any actions taken in relation to this guide is solely placed upon the end user. (This means you!)


In FYREANT's guide on installing a new camshaft, he stresses the usage of an oil pump alignment tool from GM to keep your oil pressure from falling when you put the motor back together. Instead of spending the $130 to buy the tool, I created one in CAD and matched its dimensions to a real one, thanks again to FYREANT for providing the dimensions. I decided to give a download to the 3D model I made so that everyone here can print their own tool. Below you can find the link for download as well as FYREANT's guide to installing a cam in your C7. Here’s what the tools look like in action.




There are two downloads I have provided, one is the part with exact dimensions as measured, this is to be used on SLA, Resin 3D printers since they don't have to deal with thermal expansion. The second download is for regular 3D printers printing with PLA plastic and has 1mm added to all dimensions to account for the thermal shrinking of the plastic as it cools.

If you have a 3D printer, just import the .stl into your slicer, copy the settings pictured below and print away! If not, you can order the part from a 3D printing service like 3DHubs or materialise as well as myself. If you'd like me to print your part, send me a PM and I'll get your order in, I'll print your tool for $5 and mail it to you. For those other printing services, use the same settings pictured below.

After you get your tool printed please make sure to compare its dimensions to the picture below to make sure your tool is in spec. .5mm tolerance is acceptable. Then head over to Lowes, Home Depot or the link below to buy 4 M8 x 1.25 16MM bolts. I bought stainless steel but zinc plated works as well.

That’s it! All in, it cost me less than $10 to make my tools and put them to use. If you have any questions, please feel free to ask them below!



Links:

FYREANT ‘s guide to installing a camshaft for the LT1: https://www.corvetteforum.com/forums...all-guide.html

M8 x 1.25 16MM bolts: http://a.co/d/7BjkIme


Downloads:

3D model for SLA/Resin printers (uncorrected): http://dev.chriswhite.tech/VetteDev/...corrected).stl

3d model for regular 3D printers using PLA (corrected): http://dev.chriswhite.tech/VetteDev/...Corrected).stl



Print Settings (Only for printing with PLA):



Tool dimensions:

SlowC7

Look out for the Methanol Gauge I've build for the C7 Alky Control kit coming out February 2019!
Monitor your meth levels from your phone in real time!

FYREANT

Excellent! Thanks for doing this for the Vette community!

KemahGT

Would it be possible to align the pump using the same method as an LS motor? Like this:

FYREANT

C5-VERT

I don't know if anyone has tried this on a NEW LT4 Dry Sump oil pump but I have. I am installing a NEW oil pump on a new 416 motor and when I remove the oil pump front cover there is literally ZERO tolerance between the gears and the housing. I can't insert the smallest of feeler gauges. There is absolutely no way I can insert 3 or 4 around the gear sets as shown in that video above. So I'm not sure if that alignment technique applies to LT4 GenV Dry Sump pumps. In fact it can't. Because I can't insert a feeler gauge in to save my life.

So how do you align a NEW oil pump? I literally have no idea. And I am concerned b/c I don't see any way to align it? Other than just bolting it up?


LS oil pump must have much more clearance around the inner and outer gears in the housing.

The smallest of feeler gauges won't fit anywhere around the outer gear.

KemahGT

What is your thinnest gauge? Mine is .0015. I don’t recall what I used. If you can’t get even that size inserted I would think that a jig won’t help either. It’s probably ok just to bolt it on. You might wanna check with Melling.

Good luck!

BTW, was that a stock bottom end LT4 that you lost your main bearing on? When I tore down my LT1 for my rebuild I found some scoring on one of my mains as well. Crank was ok. It did last over 30k miles without a problem. Maybe dirty builds on some of our factory engines?

C5-VERT

Yes .016 was my smallest I think. And honestly I don't even see a .009 getting in there. It's literally that tight. I am curious if the newer oil pumps are set to higher tolerances to fix that failure in previous pumps? I have no choice but to install it as is. And yes my main bearings (middle ones) went on my stock LT4 motor. I've yet to disassemble so I don't know exactly which ones yet but I will know the exact ones soon. But regardless it's for sure my main bearings.

ss2z06

I really don't know what you do seeing that this is a fresh build. FWIW this is from the GM repair manual:
Oil Pump Installation (LT1 with Z52 Option, LT4)


Preliminary Procedure

If oil pump is removed to perform a different repair and is going to be REUSED, the alignment tool EN-51267 oil pump alignment tool MUST be installed on the engine block BEFORE the oil pump is removed and left in place until the installation of the original oil pump. If EN-51267 oil pump alignment tool IS NOT installed prior the oil pump being removed AND left in place while other repairs are performed, a NEW oil pump MUST be installed.



1

Oil Pump Assembly

Note: Prior to installing the oil pump, ensure that oil pump housing gasket is fully installed in the timing chain tensioner assembly and is not damaged. If the gasket is missing or damaged, replace the tensioner assembly.

2

Oil Pump Bolt

Caution: Refer to Fastener Caution.

Procedure

Tighten the oil pump bolts in the sequence shown.



Note: Upward pressure must be applied to the oil pump while tightening the fasteners. Contact between the oil pump housing and the oil pump alignment tool must be maintained while oil pump bolts are tightened. Prior to removing the oil pump alignment tool, ensure that there is no gap between the oil pump housing and the tool. If there is a gap, the oil pump bolts need to be loosened and the installation procedure repeated.

Tighten25 Y (18 lb ft)

Special Tools

EN-51267 Oil Pump Alignment Tool



For equivalent regional tools, refer to Special Tools.

C5-VERT

I have the USB Service manual and from what I can tell the only thing you do with a NEW oil pump is align with UPWARD PRESSURE. It says absolutely nothing else, especially nothing about shimming to align. I am just going to install as it says, with some upward pressure, and torque to specs.

C5-VERT

It also says to tighten the bolts in the sequence shown. If this helps others out there without a manual.

V8!

Thanks for sharing

sonny615

The alignment tools are only for reusing old oil pump. New pumps Don’t require using them. As per GM instructions.

T/A KID

Yea I always just use new pumps

L78toLT1

I don't feel that the pump alignment process recommended by GM is the best option when reinstalling the pump. The tool ensures that the pump is clocked properly and reestablishes the vertical position but does nothing to ensure that the pump is positioned correctly in the horizontal direction. I prefer the feeler gauge technique.

C5-VERT

Look just a few posts up about my feeler gauge issues. You can't get a single feeler gauge in there, I think that technique only applies to OLDER pumps or LS/WET SUMP pumps. It was impossible to get a single feeler gauge in there for my LT4 Dry Sump brand new oil pump. IMPOSSIBLE. Even the smallest feeler gauge I had the tolerances were so small wasn't happening. So NEW oil pumps have zero options but as the service manual states: Push up on the oil pump housing and tighten the bolts in the correct sequence.

L78toLT1

I was able to get three equally spaced pieces of shim stock between inner drive gear and the inner pump rotor on my wet sump LT1. I think I used .002 material but cannot say for sure. I will admit that the tolerances make the variable displacement pumps used on gen5 LT1/LT4 a bit more of a pain to align compared to gerotor pumps.
I took a bunch of pics when building my motor. I'll see if I can find one that shows my shimming technique.

C5-VERT

I would like to see some pics I'm curious how they differ. I don't know what the deal is with new LT dry sump oil pumps are maybe every one is different. All I know is I can't even get a sheet of paper in mine. In fact I couldn't find anything small enough to shim it. Really threw me off because its extremely small tolerance between the rotor and the housing. I will know when she cranks up!! Pray for me lol I hope to have the new motor in by next week. I will for sure have plenty of vids up when she's ready! Thanks for your input!

L78toLT1

I couldn’t locate any pics with the shims installed, but I did locate a pic of the pump with the front cover removed. If you blow it up, you can see tiny gaps between the drive cog and inner rotor. I assume the dry sump pump is similar i.e. vane type, variable displacement pump? When I was building my motor, I was unaware of the pump design until I removed the cover. I was expecting to find a LS type, gerotor pump. I had to regroup and locate much thinner shim material in order to aligned the pump by as previously mentioned. For what it’s worth, I believe the specialty tool vendors may have sold GM a load of poles on this alignment tool. The plastic sleeves used with the oil pump mount bolts effectively locate the pump. It would be interesting to install the tool, apply DOWNWARD force on the pump, snug the bolts, and measure the gap between the locator tool and pump. My guess is it will not amount to much – obviously, I don’t advocate permanently installing the pump in this manner, I just think it would be an interesting data point. I still question this technique…the service manual does not say to apply any sideways force to the pump; isn’t there as much side-to-side play as up and down? Anyway, for what it’s worth, I have no oil pressure issues on my car. It stays right around 40psi at idle. Not sure what it is at WOT, but it has held together for 15K miles or so including lots of spirited driving and numerous track days. My guess is you will be just fine. Good Luck!

C5-VERT

The Dry Sump pump actually is quite different being a gerotor pump. Go up a few posts I put some pics up of mine showing the gerotor gears with the front plate off. If you look closely at my pic you can see there is absolutely zero clearance in there. I honestly just believe two things either the new dry sump pumps have less tolerance OR the feeler gauge technique only applies to LS type Dry Sump pumps or other older pumps. Not the new C7 Dry Sump style pump. It's all I can figure, unless my pump was special :-).