Stroker block clearancing
Thread Starter
Racer
Joined: May 2005
Posts: 470
Likes: 1
From: Amelia Ohio
Stroker block clearancing
I finally got my 383 stroker rotating assembly last week. 
This is my first stroker so I read a couple books and it seems fairly straight forward, however I set the crank and used an old piston and rod to see where and how much to grind but nothing hit the block. The closest one got to the oil pan rail was .037. At the cylinder walls the rod bolts came equally close but did not touch. The cylinder walls already have cast indent where the rod bolts pass by.
So, how much clearance should I have? Am I just lucky?
Chris
This is my first stroker so I read a couple books and it seems fairly straight forward, however I set the crank and used an old piston and rod to see where and how much to grind but nothing hit the block. The closest one got to the oil pan rail was .037. At the cylinder walls the rod bolts came equally close but did not touch. The cylinder walls already have cast indent where the rod bolts pass by.So, how much clearance should I have? Am I just lucky?
Chris
Safety Car
Joined: Dec 2005
Posts: 4,270
Likes: 20
From: Central Michigan
Just went through this a couple weeks ago. #1 and #8 were the only ones that hit, but I cleared the block for all the rods anyway just to be safe. I still had to grind the rods to clear the cam, only because I'm using a high-lift camshaft. After your block is bored, do a mock-up with all the parts you're going to use and check it again, with the cam
BTW, what kit did you get???
BTW, what kit did you get???
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
My four-bolt main block needed to be not only notched around the pan, but also up top center, by the cam. I'm using 6" H-beam rods though and that may have something to do with it ! 
Thread Starter
Racer
Joined: May 2005
Posts: 470
Likes: 1
From: Amelia Ohio
Low budget cast kit from Speedway. I'm trying to get it ready for the machine shop. Speedway already clearanced the rods so I should be good there, but I'll double check everything upon assembly. I guess to be safe I'll clearance everything at .050. That's for the input.
Chris
Chris
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,444
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Originally Posted by evalu8r
I finally got my 383 stroker rotating assembly last week. This is my first stroker so I read a couple books and it seems fairly straight forward, however I set the crank and used an old piston and rod to see where and how much to grind but nothing hit the block. The closest one got to the oil pan rail was .037. At the cylinder walls the rod bolts came equally close but did not touch. The cylinder walls already have cast indent where the rod bolts pass by.
So, how much clearance should I have? Am I just lucky?
Chris
This is my first stroker so I read a couple books and it seems fairly straight forward, however I set the crank and used an old piston and rod to see where and how much to grind but nothing hit the block. The closest one got to the oil pan rail was .037. At the cylinder walls the rod bolts came equally close but did not touch. The cylinder walls already have cast indent where the rod bolts pass by.So, how much clearance should I have? Am I just lucky?
Chris
Last edited by gkull; Mar 23, 2006 at 04:40 PM.
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Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Most OE and Most OE-replacement type and a Few aftermarket Hi-Po pistons come with an offset wristpin (offset from right-to-left). This offset affects the rod angle and can affect the clearancing requirements. Chances are the motor came with offset pins ... chances are new stroker Hi-Po pistons do NOT have offset pins. Unless you're certain you're working with like wristpin locations,that's another reason to double check clearancing after boring w/ new pistons ... Same goes for rod lengths and cam profiles/timing (any change from old-to-new). I like 0.050"-0.060" at both rod-to-block & rod-to-cam.
Originally Posted by evalu8r
... however I set the crank and used an old piston and rod to see where and how much to grind but nothing hit the block.
Originally Posted by 682XLR8
After your block is bored, do a mock-up with all the parts you're going to use and check it again, with the cam
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,444
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Quality stroker rotating kits don't have block and cam clearance issues. It's when you buy junk is when you have problems. I can't say enough about Bill Mitchell 
and his Hard Core kit. Every rod hit the cam lobes. Everything about his short block kit was screwed.
Other kits I only had to grind the pan rails on about 4 of the forward cylinders with big 6 inch H beam rods and big lobe roller cams.
and his Hard Core kit. Every rod hit the cam lobes. Everything about his short block kit was screwed.Other kits I only had to grind the pan rails on about 4 of the forward cylinders with big 6 inch H beam rods and big lobe roller cams.