2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

pics of my dowel pinned motor

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Old Mar 14, 2005 | 08:28 PM
  #1  
RE-EGI's Avatar
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From: NM
Cool Dowel pinned motor, on the inside

Cracked front iron housing at 450hp.

Built new motor with alot more dowel pins.

This motor should lay down serious power.

Did this on a drill press.

Made a scrap intermediate housing into a pilot templet. Transfer drilled holes into all the housings, then reamed.

drill size = 39/64
reamer size = 16mm
front housing depth = 6mm
rear housing depth = 17mm
all other housings = through
Attached Thumbnails pics of my dowel pinned motor-fihousing.jpg   pics of my dowel pinned motor-fihousingzoom.jpg   pics of my dowel pinned motor-intermediate.jpg   pics of my dowel pinned motor-rearhousing.jpg   pics of my dowel pinned motor-rtrhsngpins.jpg  


Last edited by RE-EGI; Mar 14, 2005 at 08:48 PM.
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Old Mar 14, 2005 | 11:25 PM
  #2  
88IntegraLS's Avatar
Displacement > Boost
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From: Mississippi
Man that is sweet. Mine cracked its rear iron top hole at only ~190bhp.

Post this in rotary performance and I guarantee you'll get a more enthusiastic response.
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Old Mar 15, 2005 | 01:17 AM
  #3  
Rx7MPGUY84's Avatar
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From: New Port Richey, FL
jesus, what kinda gas mileage do you see with a bridgeport like that. around 50 miles per tank? looks awesome
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Old Mar 15, 2005 | 01:25 AM
  #4  
trochoid's Avatar
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From: St Joe MO
How do you determine where the pinning needs to be or where it is of the most benifit?
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Old Mar 15, 2005 | 01:43 AM
  #5  
astrochild7's Avatar
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From: eugene, or
dude I've been waiting for someone to post sizes for the reemer/drill bit.. I've been lazy... need to get bussy
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Old Mar 15, 2005 | 03:09 AM
  #6  
chuck8313BTSDS's Avatar
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From: S.A. Texas/Tokyo Japan
Looks good. Question though, Is three through bolts enough on the compression side to hold the plates together? Or did you drill out the dowels so the through bolts can still be used?
chuck
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Old Mar 15, 2005 | 08:18 AM
  #7  
RE-EGI's Avatar
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From: NM
I chose the locations for dowel pins for a few resons, compression side feels more tensions then exhaust or intake side, more meat on the housing in those areas.

I used stock dowel pins that are hollow through the center, it allowed me to use the stock tension bolts. Thread decreases in front housing for tension bolts, but is still enough to use(all tension bolts still are used to assemble the motor).

TIPS FOR MOD

Making the pilot
-use old/bad intermediate iron housing(center housing in engine)
-castings vary, make sure enough meat is in selected dowel location to prevent breaking through.
-centering hole to be bored should be located with a gauge pin that is the same size as the hole
-put pin in drillpress chuck
-insert into housing
-clamp housing down
-remove pin
-drill out stock hole with drill(39/64)
-repeat on all selected holes
-DO NOT REAM PILOT HOUSING


Transfer drilling
-place pilot on top of housing to be bored
-locate one housing with the other using stock dowel pin locations.
-locate hole on pilot with 39/64 drill(insert drill into pilot), spin motor for a few seconds to make sure your not flexing the drill.
-clamp down housings to prevent unwanted motion
-drill(control drill depth on non through bores with a stop) use cutting fluid/oil
-repeat on all selected holes
-FRONT HOUSING DEPTH=6mm
-REAR HOUSING DEPTH=17mm


Reaming
-locate bore with reamer as close as you can
-do not clamp housing, reamer will follow the bore as reamed and needs motion of the housing.
-ream with 16mm reamer, use cutting fluid/oil
-repeat on all selected holes
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Old Mar 15, 2005 | 08:35 AM
  #8  
ultradef's Avatar
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From: Bergen County, NJ
Looks great, that is one hardcore engine. Thanks for the write up.
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