stroker crank ,clearance grinding

[grumpyvette]

Ive built dozens of 383 and 396 sbc engines and the clearancing can be done BY YOUR OWN HANDS with a standard HAND HELD drill and a few CARBIDE BURRS OR GRIND STONES in that drill in well under two hours if you take your time and total expence even if you need to buy that drill and burrs will be well under $50 total

http://www.click-onsource.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=OVAL_1-4_Shank

 

buy a 1/2" burr and a cheap drill

 

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=20776&item=4358782476&rd=1

 

place you old bearings in the block an place the crank in those bearings after coating them with axle grease

slowly rotate the crank and grind a minimum of .060 clearance anywhere the counter weights might touch the block and try NOT to grind more than about .070 any place it touches the block (use a JUMBO size paper clip as a gauge if you don,t have feeler gauges)

next assemble two connecting rods and pistons, one connecting rod and piston for the left one connecting rod and piston for the right, use old bearings coated with axle grease and no rings on the pistons, assemble them to the crank and grind anyplace the rods touch the block, grind minimum of .060 clearance and try NOT to grind more than about .070 any place the rods touche the block (use a LARGE size paper clip as a gauge if you don,t have feeler gauges)move them to the next journal and repeat untill all 4 journals and 8 connecting rods clear. now assemble all eight rods and pistons without rings and install them in thier correct locations and recheck everthing carefully.

next intall the cam and index it correctly with the timeing chain/gears, rotate the engine slowly and look for clearance issues, between the cam and rods/rod bolts ,youll need to use a small base cam if there are major clearance issues but in most cases if your cams lift and duration is under about 230 at .05 and .500 lift there should be minor if any clearance issues, usually the outside edge of a rod bolt head is the only area needing a touch up.

 

once everything clears, [color:"blue"] wash all the parts VERY CAREFULLY ,TWICE and re-oil then send out to be ballanced [/color]now you might ask why do that! well, first youll know its done correctly, and that a correctly built 383 will have a very significant hp and torque advantage over any similar 327 or 350[/b]

 

http://www.bracketmasters.com/small_block_stroker_383_cu.htm

 

http://www.prewittracing.com/newpage2.htm

 

http://www.chevytalk.org/threads/showfla...true#Post676922

 

"Pardon me for being dense GRUMPY ..but what is being grinded upon, the block?"

 

 

this may help

the comon areas are the area near the block oil pan rail where the rod bolts touch

and the lower inner cylinder walls and where the cam lobes touch the rod bolts upper shoulder on some types of rods, now you can,t grind on the cam, but you can grind the edge of the rod bolt and you can use a small base circle cam to give greater clearances

 

 

 

http://www.karl-ellwein.org/2005engineprojects/388project.htm

[Jolane]

Grumpyvette,

Thanks for the pictures and tutorial. I could have used those pictures ~2 years ago when I clearanced my 383. Do you know how thick that region of the block is? How deep is too deep (hit the water jacket)? Have you ever experienced any cracking in the block due to the clearancing?

I went slowly and kept checking and rechecking. Them I did a half fill of the block, before machining, in attempt to strengthen that area. I am not sure I really needed the fill, but I thought it wouldn't hurt (I assumed most of the heat of combustion is most likely at the top of the cylinder and in the head).

Thanks Again,

Joshua

[grumpyvette]

Do you know how thick that region of the block is?

 

it varies between block castings

 

How deep is too deep (hit the water jacket)?

 

I try to cut a MAXIMUM of .080 past the point where the rods touch the block and I use good QUALITY (H) style rods with 7/16' CAP SCREW ROD BOLTS to MINIMIZE the need to grind clearances

 

Have you ever experienced any cracking in the block due to the clearancing?

NOT YET!

 

 

 

better clerance to the block useing this style simply because theres no rod bolt projecting out of the rod shoulder area to hit the cam on the upper shoulder and the heads of the cap screws tend to be smaller than nuts on standard bolts, look closely youll see the capscrews tuck up tighter to the rod journal, the bad part about (H) style rods is most dont have a ballance pad to grind durring ballancing so if they are not a matched set in weight minoe grinding on the rod caps is done. usually not enougth to be any concern but still cosmedically a bad idea