Buying the last pieces of GPI SS1 cam kit this weekend, would love some input

[Hixson]

Well, this weekend will be the day I finally order the rest of my winter mods - I'm purchasing the rest of the GPI SS1 cam kit (I bought the cam on sale for black Friday and waited on the rest of the kit)

Build weekend is looking like the back half of March. Taking my pretty much stock 2015 1SS with a rotofab CAI and catback and adding:

Stainless Power LT headers and HFC
VMAX ported TB
GPI rodmod intake - ported and polished
some BMR suspension stuff
new tires finally (thank God)
and the GPI SS1 VVT cam kit

I need to purchase the full cam kit less the cam, and will also be purchasing the EFI Live remote tuning to be done by Ryan at GPI. I would love some input or review of the last things to purchase before this baby is ready to be worked on.

Main questions - what are you thoughts on upgrading to ARP bolts vs the cheaper GM bolts they sell. 8 lifters to remove AFM or go for the full 16 (car has 26,000 miles on it). Do I need to worry about upgrading to a melling oil pump or am I likely going to be just fine? Pushrod length, they recommended 7.400" for my application - is that correct or is it possible you all recommend the 7.425"?


Here is a link to the GPI package https://gwatneyperformance.com/produ...#configuration

Thanks ahead of time for the input - super excited to be ordering this weekend!

[go_go_gadget88]

Originally Posted by Hixson

Main questions - what are you thoughts on upgrading to ARP bolts vs the cheaper GM bolts they sell. 8 lifters to remove AFM or go for the full 16 (car has 26,000 miles on it). Do I need to worry about upgrading to a melling oil pump or am I likely going to be just fine? Pushrod length, they recommended 7.400" for my application - is that correct or is it possible you all recommend the 7.425"?

First, cool you are going to be starting soon. Good luck!

For your questions:

I went ARP. It was like $52 for a GM head bolt set, and $106 for ARP. Figured if the heads ever needed unbolted again for any reason, it was worth it to just do the ARP. Plus, TTY bolts didn't sound fun while engine is in the car.

Lifters - If you have to buy 8 anyhow, just get a full set. They are cheap, and then you have some peace of mind with all new lifters for your new cam. I have 21k miles and had some issues with a couple stock lifters.

Oil pump - everything I read suggests an upgrade, but I don't see a lot of talk about actual failures in the LS3 pump. Just a lot of talk that they CAN fail, but anything CAN.. Personally I just went with the melling stock replacement pump. Only time will tell how it does.

Pushrods - if they recommend 7.400", that's most likely what you will need if you have discussed the build with them. However, I would recommend getting the tool and measuring for correct length in your exact build. Then you didn't make a critical choice based on a general assumption.

[GPI Aaron]

Here is a link to a little info I wrote concerning the never ending questions concerning lifter preload and pushrod specs.

https://gwatneyperformance.com/lifte...ont-hurt-will/

[hammdo]

VVT oil pump is good stock, I kept mine and didn’t change it. Aaron’s links are your best source...

I bought the GMPP LS7 lifters and replaced them all @ 39k miles when I did my SS1 in my L99.

My push rods were 7.425 as I milled my heads .020, thus the difference. I’d assume GPI will give you 7.400

My build thread shows all I did (start @ page 5)...

-Don

[el Wulf]

Originally Posted by hammdo

VVT oil pump is good stock, I kept mine and didn’t change it. Aaron’s links are your best source...

I bought the GMPP LS7 lifters and replaced them all @ 39k miles when I did my SS1 in my L99.

My push rods were 7.425 as I milled my heads .020, thus the difference. I’d assume GPI will give you 7.400

My build thread shows all I did (start @ page 5)...

-Don

Agree with Don, the VVT oil pump is a stock high volume unit, due to the AFM lifters. Keep us updated....cam & valvetrain upgrade is next on my list & very interested in installing a GPI's SS1 kit w/DOD delete also.

[Hixson]

Thanks for the reply's. I will go ahead and read that article so thank you very much.

Ill be sure to start a build thread with pictures when the time comes for anyone interested

[Russell James]

Originally Posted by GPI Aaron

Here is a link to a little info I wrote concerning the never ending questions concerning lifter preload and pushrod specs.

https://gwatneyperformance.com/lifte...ont-hurt-will/

Thanks for the link, great info!

Sounds like with stock LS3 flat tops and a mild cam, stock LS3/7 lifters... a good preload to shoot for would be about .030" - .040" ish?

I've heard many recommend shooting for 50% of total plunger travel. But that sounds like more for stock (lots of PTV) situations.

With hydraulic lifters, what method do you prefer measuring PTV? Clay or checker springs/dial indicator?

If making some mock up LS3 lifters, shimming and epoxying the plunger down to make a solid checker...how far down should the plunger be made solid?

[Dylan1214]

I just cammed my stock 2014 with GPI vvt ss1 and GPI recommended and sent 7.425s...Definitely swap out all lifters. And don't worry about oil pump. Our L99s came with a reliable pump.

[LCPLPunk]

Awesome man! Looking forward to hear how your install goes!

[frankwjr]

Originally Posted by GPI Aaron

Here is a link to a little info I wrote concerning the never ending questions concerning lifter preload and pushrod specs.

https://gwatneyperformance.com/lifte...ont-hurt-will/

BTW - if the PTV is good, a .050 longer P/R can raise rpm by 400-500..trust me. and I only went .015 longer...

[christianchevell]

You should get new lifters with new baskets and ditch the AFM and go ls7 dogbone dampener if you shove it in there without dropping pan....( Dremel), the ls3 chain dampener is crap, and a mild suggestion why just start with the vvt1............you WILL WISH YOU HAD DONE MORE WITH A CONVERTER EVENTUALLY....just a thought or two...LOL Break in with br30 driven racing oil and of course new TTY bolts and head gaskets for pulling the heads and say some tr6ix plugs and a 160 thermostat......

[Rhino79]

Originally Posted by Russell James

Thanks for the link, great info!

Sounds like with stock LS3 flat tops and a mild cam, stock LS3/7 lifters... a good preload to shoot for would be about .030" - .040" ish?

I've heard many recommend shooting for 50% of total plunger travel. But that sounds like more for stock (lots of PTV) situations.

With hydraulic lifters, what method do you prefer measuring PTV? Clay or checker springs/dial indicator?

If making some mock up LS3 lifters, shimming and epoxying the plunger down to make a solid checker...how far down should the plunger be made solid?

We use checker springs and solid lifter. We normally run .078-.100 preload on stock lifters.

I just shim under the cup until it is solid. The check springs are very light, and I have gotten away with checking with a regular lifter, being careful to not squeeze the oil out. But its always best to check it with a solid combo.

[Mike14bumblebee]

Originally Posted by christianchevell

and a mild suggestion why just start with the vvt1............you WILL WISH YOU HAD DONE MORE WITH A CONVERTER EVENTUALLY....

I was wondering the same thing. Why not go with the SS2? I can see y not going with the 3 if your not into the racing part and just fun driving or daily driving, but y go thru all the work for a stage 1 cam? Just inquiring for my future mod lol. 👍 And can't wait to see how the build goes for you

[Rhino79]

Our ss1 vvt has been 11.20s with a 5c converter, 3.91 and in stock heads. It rips for a smaller cam.