Hey guys I am looking to buy a camaro with a 408 stroker done by calspeed. How would I go about checking that it is actually a 408 forged block? I don't know the seller I'm sure hes a good person, but I don't want to just take his work for it. If I took it to a shop with they be able to tell me?

 

The best thing you can do would be either look for a PN on the pistons by sticking a bore scope through the spark plug holes, or pulling the pan and looking for info on the crank counterweights. If you pull the balancer off and see that it's got grooves cut in the snout for a key way, that should tell you it's an aftermarket crank, but not necessarily what stroke or bore.

 

I don't think the owner of the car would let me pull the oil pan plus I wouldn't want to lol. Just dropped a k member last weekend and what a b**** it was! I might look into the bore scope?

 

would the part number show on the piston if it has 25k miles on it or would it be covered in carbon?

 

Can't say for sure, I've seen some where the pistons are covered and some weren't. Depends on the tune I suppose.

 

Anybody have any ideas on what I should be looking out for when buying a car with a used 408 stroker or is it like buy any other car? make sure it doesn't make any funky sounds and check for leaks, etc.

 

Maybe try to contact Calspeed for build confirmation? I've gotten a couple shops to confirm info when letting them know I am purchasing the motor/trans/car.


Used built motor I suggest some extra steps like compression test, visually check any hose and connection you can, get it on a rack to inspect chassis and braces, have a tuner friend check the tune, and an alignment check. Test drive if you can or have the seller take you for a spin.

 

I sent Calspeed an email just waiting on a reply. Rick at Synergy explained to me how to check if it actually a stroker so I am going to try his method. I don't have a tuner friend so thats out of the question. Compression test I can do as well as the other things mentioned. The guy selling the car bought the car from someone else who originally had the stroker done plus a procharger setup. Idk if the procharger has hurt the stroker though as I read on these forums that 408 strokers and boost don't mix well.

 

Thats news to me. I always heard good stuffabout iron block strokers and boost.

 

ya it was news to me as well!

 

I started hearing about this about a year ago. I saw a video from Nelson racing engines on YouTube explaining this. I think it is in regards to pulling the piston out of the bore too far which allows the piston to rock a lot more then if it stayed in the bore and was supported more. I didn't like hearing that since I also have a 408 and plan on boosting it in the future. I plan on researching it a lot more and when the time comes, just change the crank and rods for something stronger and dial it back and make it a 370.

The aftermarket blocks are soposed to remedy this according to what I read, it's just a problem running factory blocks.

 

That's an old video and he was describing an old problem. WAY back in the day, there were a lot of pistons that were improperly designed and it caused the problem he is talking about.

Piston skirts are typically barrel shaped, so there is a "break-over" point in the skirt where the diameter is largest. This break over point is where your machinist measures the piston to determine piston-to-wall clearance and if it falls below the bore at BDC, the piston-to-wall clearance increases and allows the piston to rock. Its not just bad for boost, its just bad period.

Those old designs had this break over point too low in the skirt because the original designs expected a longer cylinder. Since then, the designs have been corrected and even improved upon. The break-over point in modern pistons have been moved further up to keep the piston supported @ BDC with even longer strokes.

 

Hi, as I have worked as a "tech inspector" this is a easy measurement.

First find TCD #1 or #6
Remove # 4 sparkplug.
Remove # 4 rocker arms.
Fill cylinder with liquid (Diesel ?) from a C/C (baby bottle) flask.

ADD head C/C (67), find displacement of the cylinder.

This is of a "level" block @ 45 degrees of cylinder angle.

This is only a "close" test, not as good as when bore/stroke tools are used.

Lance

 

Thanks for the update on this info, put my mind at ease

 

Just a thought, but if have HPTUNERS available read the tune and check the cylinder volume on the engine-general page. If it was properly tuned, that number would be something like .836 iirc. Vs .75 for a 6.0

 

I don't think the guy will let me pull off the rocker arm on his vehicle. I will have to check to see if he has it tuned by hptuners. Rick at Synergy motorsports told me to stick a long zip tie down one of the spark plug holes with the spark plug removed and then turn the crank pulley with a wrench to bring the piston all the way up mark the zip tie and then bring the piston all the way down and mark it again. He gave me the measurement on how much it supposed to travel if it actually is stroked so I am going to try that. I'll also do a compression test, but idk if that will tell me much about the motor being in good condition, but at least it will give me something I guess.

The body of the car 235k miles and the procharger p1sc kit and stroker motor have only 25k miles. The guy has 16k in reciepts and is willing to sell the car to me for 10k. The body of the car is clean and the interior is pretty clean. Do you guys think that is a good deal? It also has 3.73 gear and an ls6 clutch, but theres no way to prove that.

 

Just be very careful on the purchase. That zip tie method sounds very good & easy to find if it's stroked.

A procharged 408 with the 10 bolt & ls6 clutch. If you decide on purchasing the car be prepared to spend more $.

My personal opinion is I would steer clear. Good luck.

 

I'm starting to think I should stay away also, but the dam car has everything I want and it was built to pass cali smog!

 

You'll have to make the decision. Don't rush on it. You may be the next one selling the car. Or you got a good deal.