I've been around the LT1 scene for quite some time now (bought my first one almost 9 years ago and I've had my current SS since 2007) but I've finally started to go beyond the "bolt-on" market. I should stress that this is a very long term project. I've had this car a long time and haven't been able to dump a lot of money into it at once due to other priorities in life (college, saving for a house etc.)

The Recipient:
'97 Camaro SS M6 that I bought just after graduating high school. The car has just over 150k miles on it so I was worried about throwing a cam into it then spinning a bearing.

Brief rundown:

• Pacesetter Headers
• 3" ORY into SLP 2OTL
• BBK 52mm TB
• BMR Lowering Springs
• SLP Valved Bilstein Shocks
• BMR LCAs w/ Relocation Brackets
• BMR Adj Panhard Bar
• New Moog ball joints, tie rod ends, strut mounts, etc.
• LS1 front brake swap - Hawk HPS pads w/ DBA slotted rotors
• LS1 Aluminum Driveshaft
• !AIR/EGR
• 17x9.5/11 ZR1s with 315/35/17 NT555R

The Donor:
LT1 crate motor - pulled out of a '95 Trans Am with 60k miles on it. Supposedly it has a hotcam in it however I haven't dug into it that far yet. It was a complete pull from the donor car with wiring harness and PCM. I'm considering doing an OBD-I swap but haven't decided yet. I've pulled a valve cover and the heads were VERY clean with factory 1.5 ratio rockers.



The plan is still in the works but I'm looking to put down 360-375 without much work to the stock heads. For the cam I'm looking at Ai 226/234. I'm hoping to get some guidance on exactly what I should do.

High level this is what I'm thinking:

Shortblock: Pull oil and look at bottom end. If it looks good install ARP hardware and re-seal. Also looking at upgrading the oil pump spring (white spring) while I'm in there.

Should I look at new pistons/rings? Crank/Cam bearings? This is a 60k mile shortblock so it should be in good shape but I'd rather error on the side of safe than sorry.

Top-end: Ai 226/234 complete kit, heads disassembled and dipped/cleaned. Maybe light port matching. Might run Impala head gaskets to slightly bump the compression ratio. Will be running 91-92 octane.

Anything else I need to consider? Factory injectors fine? May look at upgrading the clutch while I'm doing the swap as my factory O'Reilys replacement probably won't like the new power. Spec 2? Want it to be pretty easy to drive but also have some bite.

 

If you're only looking for 360-375rwhp then the AI h/c kit is total overkill with your M6. Just the AI cam and an electric water pump will put you in the ballpark.

DO NOT go replacing bolts in the bottom end without checking roundness or getting parts remachined. Different fasteners have different clamping loads and will distort the roundness of your bearing caps on both rods/mains. The only way do this is to have the crank out and check with a dial bore gauge or inside micrometer. ARP rod bolts will have to be pressed in which requires removing them + having them resized and ARP main fasteners usually require a line hone.

The oil pump spring certainly won't hurt.

I'd run it with the cam. 60k is nothing.

 

I was just planning on doing the complete cam kit. Not sending my heads to AI, at least not for round 1.

• Ai Billet Steel 226/234 LTx Camshaft
• Performance Springs Inc. MaxLife Beehive Springs
• CompCams Beehive Spring Steel Retainers
• Machined & Hardened Steel Locks / Keepers
• CompCams Hardened Steel Spring Locators
• OEM Quality Steel Jacketed Viton Seals
• K-Line Valve Seal Installation Driver
• ARP 7/16" Pro Series Rocker Studs
• CompCams 7702 Pushrod Length Checking Tool
• CompCams 1605 Ultra Pro-Mag Rocker Arms - 1.6 Ratio
• Ai Hardened & Black Oxided Steel Guide Plates
• Ai 4130 One Piece Chrome Moly Hardened Pushrods 5/16" x 7.XX" .080" Wall
• Fel-Pro Gasket Kit - Timing Cover gasket, Water Pump gaskets, and Crank/Opti/Pump drive seals
• Fel-Pro 1284 Intake Manifold Gaskets w/RTV

I agree with you, 60k is nothing but at the same time I'd rather do anything that should be done while the motor is out. If I decide to port the heads and up the RPMs later I'd like the short block to be ready for that. While the engine supposedly only has 60k I have no idea how hard it was beat on. I only know that the heads were very clean on the inside. Budget is a concern as always so if the bottom end doesn't need anything I'll leave it be. I planned on using plastigage to check bearing clearance when installing the ARP hardware but will changing out the hardware require me to have the crank/connecting rods checked and balanced? Also should I look at running a forged budget piston or will the factory pistons suffice? I think the factory crank and rods should handle my goals okay.

 

Run a thinner head gasket like the Impala one to increase CR, I think it was .027 compressed or something like that.

Forged pistons will be overkill for a NA setup if you're not spraying, boosting, or going solid roller with really high RPM. The expansion of a forged piston is also greater than the hypers that are in there now so the possibility of having an engine with piston slap is much greater because of added PTW clearance, not what you want for a NA street toy. New pistons will also require having your rotating assembly rebalanced which is $$$ not spent on parts that make horsepower.

Like I said, ARP hardware will require a complete teardown of the engine and costly machine work for your goal. It is definitely not necessary for the AI h/c you want, there are guys on this forum pushing these motors much farther than that on stock parts. At minimum, you'll need to have the old rod bolts pressed out, new ones pressed in, rods resized, and have the block line honed... but you'll have a few hundred bucks in machine work for no real reason. The 226/234 isn't crazy at all. It's a little on the wild side but mostly moderate.

You can't rely on plastigage, it's just a method to double check the measurements you make with a set of real machinist's tools.

If you're dead set on getting it rebuilt, the best thing you can do is get the crank turned and open up the bearing clearances from stock a little bit. They are pretty tight from the factory. Like 20 on the rods and 25 on the mains.

 

^^^The path of least resistance. If you dont plan on reusing stock stuff fine but youre going to spend a lot more in the end and only end up with a small amount more power due to your octane limitations. Up top your parts list looks good. If youre going to get all ARP stuff down below definitely talk to a good machine shop to get those rods right and get that crank right. If you want a little bit more power for not a lot of money, think about getting your crank lightened and knife edged while its out.

 

Options with small block chevy are unlimited let alone 2 small blocks. I dont think there is a wrong way to go here.

LT1 crate motor - pulled out of a '95 Trans Am with 60k miles on it. Supposedly it has a hotcam in it...
Should I look at new pistons/rings? Crank/Cam bearings? This is a 60k mile shortblock so it should be in good shape

U cant do a compression test but u can do a leak down test on the spare eng. Leakdown will tell u the condition of the entire cyl - if rings are worn or vlvs leaking. Compression could identify which in cyl leaks - rings or vlvs. U need an air compressor and stop the cyl at TDC when both vlvs closed for leakdown.
If leakdown test good all cyl then recam with new vlv springs. With eng on stand just for self assurance u can carefully inspect the main brgs and or rod brgs. Be sure to retorque bolts with calibrated torque wrench.

But u can do both compression and leakdown on the engine in the car. This will tell u whether the car needs a newer eng at all.

U can do the cam and vlv springs to either eng. IMHO u can save a ton of work by recamming and respring the eng in the car. U still have a lo mi spare ready if needed. But even a 150k mi isnt even 1/2 way for a small block chevy. If your worried 'bout spinning a bearing buy a PCM4less tune with rev limit below cam redline. Or install a MSD rev limiter or even a MSD6AL with limiter built in. BTW u will need to drop the oil pan to get the timing cover off and will need a pan gasket also if u break the stock gasket - be careful.

Swapping engs is a lot of work. Building engine out of car is fun. If my car I would cam the eng in car and build the spare and much as i can afford. Yes cam the eng in car and get the spare ready.

cardo

 

60k is nothing. If you're talking a long-term project I'd go ahead and save up and do the full Ai 200cc heads and cam package. I had a stock-headed 'cam only' setup that made 358 and it left me wanting after a short while. I did the 200cc heads and 228 cam later on.
That motor in the picture is clearly going to need a new oil pan gasket in addition to everything else you're talking about. Nearly all of these things have oil leaks at this point if they haven't been messed with yet.

 

http://www.ellweinengines.com/

I was going to link up the college budget 355 but the link isn't working. Maybe email Karl and see if he knows what is up with it. I'd do the bottom end now for moderate strength so the car has room to grow with power down the road, its inevitable.

 

I'm definitely not putting the engine in my car without pulling oil pan and inspecting the bottom end. I'll obviously put new gaskets on it... oil pan, intake, heads, etc. I've actually got a pretty complete gasket set from a friend who works at an engine repair shop.

Ai 190/200cc heads are definitely something I'd like to add in the future (obviously because of this I want to make sure I have a stout shortblock that can handle 375-450rwhp) but I've had the car for 6.5 years and it's been relatively stock all of it's life. I've done full exhaust, completely redid the suspension, etc. but power output hasn't increased drastically. Because of this I plan on going cam only for phase 1. It shouldn't be too hard to add heads a year or two later and heads are pretty pricey. My new motor has 643 heads so that is one of the two castings AI will port. Pretty sure my '97 heads are 374 as well so I could send either set off to them.

 

I've seen it before, see the first sentence in this thread. :p Been reading LT1 discussions for 9 years now.

 

It's unlikely that the heads on your 97 are 374 castings. They should be 561.

 

If your going to mod it...I say go big or go home! Keep in mind a stock LS1 with headers and a tune is making 370ish HP...320-330 at the wheels, why go to all the trouble to just keep up with stock LS1's I've done the cam only setup before, it was OK....I guess...I'd get a heads and cam package if I was in your shoes and aim for 400+ hp...just saying....you don't want the LS1's and new 5.0's slapping you around!

 

My local machine shop quoted me $80 to resize all rods for ARP bolts. Since your pulling the pistons, you need to hone the cylinders (can just use a ball hone and a power drill and YouTube or pay $120 for a shop to do it) and new rings from rockauto or whatever. Not costly at all.

 

This thread has NOTHING to do with LS1's. I could've bought a half decent LS1 for the same price as my SS when I bought it in 2007. I had no interest in purchasing an LS1 then nor do I now. For the record, my car runs dead even with my friends lid/catback/suspension LS1 car and I pull him a little bit on the shifts.

 

It's been a couple years since I've had the valve cover off so I cant say with certainty. Not a big deal either way.

 

Update: Tear down has begun on the motor. Please excuse the mess.

Tore off most of the accessories:


Bottom end:


A couple close ups of the bottom end:




I picked up a harmonic balancer puller set the other day so I'm gonna flip the motor back over and work on getting the harmonic balancer and opti off to pull the cam. What do you guys think of the bottom end? I'd like this to support 375-425 rwhp long term without feeling worried revving a little north of 6100rpm. (The cam I'm looking at peaks at about 6400 but I'd probably stay a little below that to be safe)

 

It will definitely support that amount of power and RPM no problem. More RPM than that won't play nice with your bearings.

 

Finally got around to pulling the heads and front cover off.









Look what I found! I was told the motor might have a hotcam in it. (Had a receipt for cam installation)

 

You're not going to know unless you measure the duration and lift or pull it out.

But yeah, someone's definitely been in there.

 

LMAO....a bit touchy about LS1's eh? You completely missed my point , but I'm glad you came around and up your long term HP goals at least...THAT was the point. I've been there and done that with a cam only setup, if I had to do it again I'd gotten heads at the same time; but hey don't take my word for it. For the record my LS1 Firehawk with longtubes and a tune has toasted every stockish LT1 I've ever encountered, I question your friend's driving ability....my 383 LT1 is a whole different story. Best of luck anyway!