This winter I'm looking to take out the KB hyper pistons that are in my shortblock and do a budget rebuild on the block while I port up the heads. My block has about 30k on it now, but I didn't build it and judging by what work was done to other parts, I don't trust it unless my hands did it.

I can't seem to find any information on any shelf piston when it comes to how much wall clearance they need for expansion? I want to get away with just doing a tank and tossing a quick plateu hone on it. I figured last ditch effort was to have custom units made undersized to account for the expansion, or go with zero silicone units like Venolia which have almost no expansion. Car will be down after the first snow, and won't come out until it is spring so time waiting for pistons to be made is nothing.

Shopping list

Machinist:
Check deck
check bore, Plateu hone cylinders
Tank and clean
Clearance block for 383 stroke
Install new rod bolts, resize rods
Install cam bearings
Freeze plugs
Balance

Parts
ARP Rod bolts (I think there were some with a smaller head for stroker engines)
383 Stroker crankshaft
Engine Gasket set
Bearing Set
Valve stem seals
Recondition SS valves I already have
Forged pistons, stock compression
New opti
New Waterpump
Plugs and Wires
ARP Head Studs
LS7 Lifters (I have the older design Comp-R's)
Not sure what I am going to do for springs, right now I have the older design 918's that are holding up.... just don't trust them
Hardened pushrods

I'm not looking for something to make 1000 HP, I just like the peace of mind knowing I did it myself and the parts I put in won't fail on me if I get on the pedal hard every now and then. I hardly ever go to the track and the car is my DD until winter. So I figure a good H/C combo, exhaust, built engine would be good for me to have some fun with. I'm finding little kinks and quirks with the car everyday, so I'm just going to start fresh with it and get it all hammered out over the winter. My plan was to paint the car, but I'd rather go fast.

Any thoughts or does all this seem too far fetched to do without having the block bored again? I'm not going to lie, cost is a major issue with me (3 daughters and alot of bills) I can piece most of the parts together this fall and get cracking right after the first of the year.

 

Well I put Probe Industries forged aluminum pistons and 6.0 inch rods in mine, but haven't fired it up yet so all I can say is they fit.

I don't know the silicone content and don't know the expansion rate, but the "running clearance" is on their website as 0.002 to 0.006".
Here is a link:
http://www.probeindustries.com/Pisto...t/Chev_350.htm
Have fun with the build,
Jim-

 

They are an awesome piston
Clearence is usually .002-.004 on the SRS series.
Real big in the ford crowd

 

I would probably go with a better rod too.

 

Really? I've never had any issues with Eagle Rods in my 420A engines (one was about 550bhp)


I'm just worried that I am shooting myself in the foot by short changing on the machining and not just building another long block from scratch. My gut tells me to do it right, but my wallet (and my wife) is telling me to do it the cheapest way possible. ahaha

I may put in a call to Probe and see what they think and if I'm a nutball for even trying it.

The car now never sees over 4500rpm and I get on it hard about once a week. There aren't many places to open the thing up here in the city, so I just go light to light.

 

well you should have a pretty tight sideskirt clearance with the hyper's, and if you got a .030" over forged piston, it needs more clearance. so you got room to hone a few thou away to get perfect wall and perfect clearance for each piston. dont see a need to start with a new engine just because of that. I guess you need to mic each cyl. to see what the current sizes are exactly, and what size the ".030" " pistons will come to see what pistons will be the best fit and still allw you a few thou to clean up the cyl. walls.

and dont leave off line honing the main caps. and dont forget to clearance the oil pump if you use main studs. I broke my F'n main cap when I tightened down the oil pump cause the stud was contacting the bottom of the pump and it pulled the threads out of the cap. DOH!!!. then you'll be finding a new cap, and line honing again.

good luck man.

and the eagle rods will be fine. just not the lightest, or the strongest. but the best bangforthebuck IMHO. thats why I went with them.

chris

 

I'm heading over to talk to my machinist this weekend in person and to look over some of this books. He doesn't see the need for a complete buildup on this block, but he said it depends on what it all looks like when I bring it in to him.

I think right now my plan is going to be to just build another LT1 383 on a stand and just take my sweet *** time with it. The 355 in it is in good shape, just the leaks from the waterpump shaft ring and rear main that I can repair and keep it going until the real deal is fixed. Afterwards I can put that thing on Ebay or put it into another car.

 

I am running Mahle forged pistons, with 6" forged Eagle rods in my 383 LT4. I have between .002 - .0025 skirt clearance and the sucker is really noisy until it warms up. Its the first motor I ever built with forged pistons, its kind of anoying but I guess thats the way it is.

You cant here it in this video because its warm.


http://videos.streetfire.net/video/5...6c012862ea.htm

 

I run the KB hypers and they are a little chatty for about a minute or so.

 

Probe pistons are junk - try weight matching them, you're lucky if they're within 8g of each other.

Use some Mahle's or Wiseco Pro-tru.

 

I did, they were all within 2g of each other. They were probably made on a wednesday. BTW those 6" rods you sold me were really nice.

 

I used Probe pistons twice - a 572 BBF, and a 347 SBF - both times the pistons were way off from each other, now they don't get my business.

Glad those rods worked out for you, they're good ones for the $ spent.

 

I have these on my 6" rods. With the chamber I have, it gives me 9.5:1 cause I designed it have a blower ...when I can afford it.

http://www.jegs.com/webapp/wcs/store...-1&showValue=2

They are a bit pricey though. But they were within 1 gram of each other.

 

You need to take into account that the pistons generally have the clearance machined into them. A 4.030 bore piston, designed with .004 clearance generally has the piston around .004 undersize for clearance. The extra honing usually is needed when the usage requires more clearance than the typical usage of the piston (high dosages of N2O for example)

I also have a used set of 383 6"rod 16cc disp SRP's if interested. I can give you an OD measurement if needed.

 

yeah, the plan is to see what measurements I have when I pop the heads off and check the bore.

I'm not running nitrous.
I'm not planning on boosting it, but I don't want to limit myself later if I do decide to do it.


The cost savings for me just rebuilding the current block vs redoing the whole things is actually minimal. The cost of new rods, bore, and core are probably worth the piece of mind and I can sell the good 355 that is in the car now to offset the price.

Either way I am still hammer out the options, but the budget is going to play a big role.