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G8 GT DIY Camshaft Swap

64K views 668 replies 21 participants last post by  JCMG8  
#1 ·
I have been to three shops in the Washington DC area to get a quote to upgrade my camshaft and none will provide a quote. Each is 2-3 months out before they could even start the work, if they did provide the quote. Either there are not many shops around or everyone has money to spend...

So, I have decided I am doing this myself. Is there a DIY guide out there or a mechanics web site I could subscribe to in order to provide some general directions in case I need them? I understand the basics of what needs to be done, just don't know the nuances.

I have seen the various camshaft discussions here on the forum so, I can probably pick out what to buy from those threads. I have never taken an engine apart if you will but have replaced everything over the years, water pumps, fuel pumps, starters, alternators, brakes, etc..

Figured what could happen? I get it done or it gets hauled off to have the engine replaced sometime in the future.

Any general direction would be appreciated.
 
Discussion starter · #668 ·
Thanks for the info.
 
Discussion starter · #665 ·
I just did a 578 mile roundtrip yesterday. GT averaged 23.3 mpg at roughly 74mph.

I think I am solid for a while, assuming I don't get the itch to add more hp.

Appreciate all the help.
 
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Discussion starter · #663 ·
My car is still stock height so, I would guess I'm ok.
 
Discussion starter · #660 ·
Nope, because I am retired. LOL, no more work for me.

I know this sound a little sad maybe, but I always wanted a car that has that cam lope sound since I was 16. I paid for my kids college and a couple marriages, then concentrated on saving and paying off the house. I was finally able to spend some money on me. So, the GT was perfect. Awesome looking car, added more hp than stock and I can stand behind the car and listen to the exhaust. I am a very happy camper.

Should I go for more HP as MGMGXP has suggested? At this time, probably not. But, we'll see.

Again, thanks for all the assistance fellas.
 
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Discussion starter · #658 ·
Ha! Ha! I would not have expected a different response from MGMGXP.
 
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Discussion starter · #655 ·
I was quite happy with PatG's work. He sent an initial tune in November 2021 that I loaded and then ran a log file which I sent to him. A few weeks later in early December, he sent me an adjusted tune. I then sent him a log file after loading and driving the car. Out of the blue in January 2022, he sent me a small update with a very few tweaks he had made. I wasn't expecting this one. Loaded it and then sent him a log file for his records, if you will.

That was it. Nothing additional was done.

My goal from my initial consulting call with PatG was to adding about 125hp to the car. According to him, the GT actually delivers around 305hp out of the factory, not the 350-360hp that was in the sales brochure. So, assuming the 305hp is correct, 305hp to 439hp, I am quite happy with the result.

I guess someone could argue the 305hp, but I have no knowledge or technical information to question PatG.
 
Discussion starter · #653 ·
When I got there. PatG had done the tuning originally and I had no issues really.

The only issue I had, if it was an issue, is that I would smell raw fuel for a few seconds when it first started. I haven't been able to do the smell test, smiles, since I got it as it has been pretty windy here for the past day or so.

I did take it for a two hour ride yesterday after I got the car back. A fair amount of stopping and going, and some Interstate speeds. Ran fine.
 
Discussion starter · #651 ·
Ok, got it. I'll use the M1-212 in the future.

Thanks.
 
Discussion starter · #649 ·
I think the part number was M1-113. Short probably?

Should I change to the 212 in the future?
 
Discussion starter · #647 ·
So, when I completed the engine mods in Nov 2021, I did change the oil after 500 miles. I have put a little over 4,000 miles since that first oil change. Then I changed it last weekend a few days before the dyno/tune. The oil in the engine at the time of the tune had about 100 miles on it.

I am guessing I should be good for another 5,000. Used Mobil 1 5w30 and a Mobil 1 filter.
 
Discussion starter · #645 ·
I have been nervous since I scheduled the dyno and tune two weeks ago..
 
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Discussion starter · #643 ·
Ya, I didn't sleep the night before. I had it torn down further than I had ever gone before.

Baby held together though.
 
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Discussion starter · #641 ·
Well, 15 months after the build, I finally took the GT to a dyno/tuner.

424hp for the first run, after some tweaking, it settled at 439hp and 409 of torque.

I am a happy camper. I wanted 425 minimum when I was done and I have a little more.

Great thanks to all of you that provided assistance during the mods!!

Jeff
 
Discussion starter · #633 ·
Ha, Ha on the remote start. What are you talking about? My GT doesn't have that option???
 
Discussion starter · #632 ·
Took the radiator out of course..

If you loosen a few bolts holding the air conditioning lines in place, I got my son over here to help me lift and hold the condenser up high enough that I could remove and install the new cam. I had him hold while I did the cam chore. I did see a youtube video where the guy used bungie cords to hold the condenser up high enough.

This saved me from having the air conditioning system vacuumed and recharged.
 
Discussion starter · #630 ·
I got the antifreeze crossover pipe squared away on the top front of the heads yesterday.

I believe that was the last of my mod list for the car. I'm sure other items will pop up in the future, but this was the last of my engine mod list.

I can't thank the forum enough for the help!!

GT runs great for me, at least..
 
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Discussion starter · #629 ·
Clarkie, you saved the day with that video.

Thanks Pony Man..
 
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Discussion starter · #626 ·
No issue.
 
Discussion starter · #624 ·
I don't have that on my GT..
 
Discussion starter · #621 ·
There is a spacer provided with the Kooks exhaust. Spacer goes against the head, then the guide tube, then the longer bolt supplied by Kooks. For the oil pan, the lower end of the tube just slides in the slot at the top of the oil pan.

Is that what you are asking?