I was talking to a machine shop guy and telling him I was interested in putting together or buying a 383 stroker motor. He said he would not do it because you get alot of loud piston slap from them on account of the clearances you have to run. He said if you try to get them with tight clearances you end up scarring the walls? Anyone care to support or rebute this opinion?

If your using hypers maybe, But we have been using the SRP pistons with the 6 inch rod with no problems and all the blocks we prepare we torque plate hone them which makes quite a differance as compared to shop that doesn't.

If interested I have a NEW 383 engine kit with a internal balance Scat 4340 Crank all balanced , Micro polished, SRP flat top pistons for a 6 inch rod that are pin fit and a set of Scat 6 inch rods with the 7/16 bolts and both ends have been clearanced comes file fit rings all fitted and it also comes with a BRAND NEW GM BLOCK that has been line honed with an ARP main bolt kit, Decked to 9.000, Stroker clearanced, Bored and torque plated honed with peformance cam bearings installed and brass freeze plugs. Machine work has been done on a HAAS 4-axis CNC machining center and the block was plated honed in a Sunnen 616. And FREE SHIPPING IN THE U.S. for 3295.00

The Customer is going to a big block and just wants to get rid of it, If you want some pics pm me and iwil get some to you.

Perry,
READ THIS CAREFULLY!
You need to go find another machinist! Nothing more needs to be said!

wow.... GMPP sell's alot of the 383's in 2 different versions......... does every motor come back to us because of piston slap?

i would go back 1 post and take the suggestion

Man, Tom Parson stated my feelings exactly,,,
I have put together a number of 383 strokers, with Hypers, and have never had a problem with any noise at all. They should sound like a solid 350 at idel, but rev and sound like a bear. I have never heard any piston slap until they are starting to get real worn out...nothing else to say.

Fred.

Perry,
As much as I hate to, I have got to agree with Tom on this one. Piston clearance has nothing to do with the fact that the motor is a "stroker" ! A stock 400 has the same stroke as the 383 and it doesn't have piston slap. Clearance is strictly determined by the design and material of the piston. Some pistons need more clearance than others when cold, but once they are warmed up, they all run at about the same "hot" clearance. Still, it has nothing to do with stroke. I am betting that your machine shop does not do much in the way of performance work. That does not mean that they cannot do good work, however.

Thanks for the info guys. Sounds like a stroker could be fine then. I will just have to find another machine guy to do the work I guess. Anyone know any "GOOD" machine guys in or near Grannts Pass Oregon.

Maybe your machinist just doesn't know what he's doing. He probably built some 383's, didn't do them right, had customer complaints, and now rather than figure out how to build one properly, he's just not going to do it at all.

I don't know what using hypereutectic pistons has to do with causing piston slap, seeing as how you can run tighter clearances with them than you can with most forged pistons.

DZ and Bill already said it, imho...

BUT I have to say this!! My Machinist that helped me build my junk 301 years AND years ago had me turn my pistons around so the notch faced the rear as well as he ground the crank about .001" more undersized from what he called norm. b/c he said it would run good, but with some piston slap when cold as well as that I would need to run at least 30 wt oil in her!!

BUT that she would go as high as it could before the points bounced set up loose like he set it up!!!

AND IT DID........

pdq67

I have a 400 +.030 and TRW forged pistons. I do have some slight slap when cold but it goes away quick.Before installing it into my Camaro I did a complete teardown to inspect and install new bearings.
I just had heads off (again,after 5 years)to install Protopline 200's and looked at honeing marks.Still looks great after alot of hard runs.