main cap ?
- Thread starter sean
- Start date
Re: main cap ?
the problem, according to my shop, is that when you add splayed 4 bolt caps, you can drill into the water passages. Obviously not a good thing. I don't know how deep you go or the clearance specs or anything...just what my shop has told me. They didn't want to convert my block to 4bolt when they bored it, so I appreciated their honesty and non-desire to f up my block.
obviously a ton of people have converted to 4 bolt w/o problems. But i bet a few that have bearing problems shortly after a 4bolt conversion may be seeping water into their bearings
the problem, according to my shop, is that when you add splayed 4 bolt caps, you can drill into the water passages. Obviously not a good thing. I don't know how deep you go or the clearance specs or anything...just what my shop has told me. They didn't want to convert my block to 4bolt when they bored it, so I appreciated their honesty and non-desire to f up my block.
obviously a ton of people have converted to 4 bolt w/o problems. But i bet a few that have bearing problems shortly after a 4bolt conversion may be seeping water into their bearings
VermontTy
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Re: main cap ?
I just found this...
http://users.michiana.org/rosss/modela.html
"you drill too deep piercing the water jacket at the base of the stud hole and as a result the stud will leak when the engine is assembled and running."
"In the event you have pierced the water jacket at the base of the stud hole plug the pierced hole with two part plumbers epoxy this will act the same as the dentists filling."
Ever heard of such a "fix"?
I just found this...
http://users.michiana.org/rosss/modela.html
"you drill too deep piercing the water jacket at the base of the stud hole and as a result the stud will leak when the engine is assembled and running."
"In the event you have pierced the water jacket at the base of the stud hole plug the pierced hole with two part plumbers epoxy this will act the same as the dentists filling."
Ever heard of such a "fix"?
Re: main cap ?
The stuff that finally worked for me was Loctite 567...It's a "white" loctite that withstands over 400 degrees F.....Yeah, my head studs leaked the first time around using a "teflon" based brush-on stuff....It was also white but it definitely didn't work.....I ran the motor for about an hour (never drove it), then yanked it and disassembled it to check for damage....when I pulled the main caps, one of them had some droplets of water around the bearing area....that ended up being the ONE splayed hole that made it through to the jacket....so I found it by accident you could say because I tore the motor apart for having run the motor with leaky "head" studs....then I plastigaged the rods and mains and found the clearances were way off spec, so back to a "different" machine shop for some crank cutting.....all this on a "standard" uncut 4.3 crank...I never even brought these issues to the first shop's attention, because they screwed up to begin with....why take the motor back to someone that has screwed up in the first place already...I found out the hard way that these motors have to be within certain specs/clearances if you expect them to live....well, at least my motor didn't blow up or get damaged....never trust any machine shop's work when they give you assembled shortblock....CHECK THEIR WORK before you assemble the motor....get a qualified person to pop off the rod and main caps and plastigage them at the very least...whoever assembles the motor is ultimately responsible if the motor fails for not having checked the machine shop's work before assembly in the first place...you can avoid all the crap I went through before the motor is in the truck running and you find out you don't have any oil pressure or you spin bearings.... below are the recommended specs you should give to the machine shop when they work on your motor...These motors should not be treated as regular 4.3's....
Type: V6
Disp.: 262 C.I. (4.3L)
Horsepower: 280 BHP @ 4400 (Syclone) 285 BHP @4400 (Typhoon)
Torque: 350 lb-ft @ 3600 (Syclone) 350 lb-ft @ 3600 (Typhoon)
RPO: LB4
Bore: 4.00
Stroke: 3.48
Comp. Ratio: 8.35:1
Firing Order: 1-6-5-4-3-2
Oil Pres. (Min) 6 psi@ 1000 RPM, 18 psi@ 2000 RPM, 24 psi@ 4000 RPM
CYLINDER BORE:
Diameter: 3.9995-40025
Out of
Round: .001 (production) .002 (service)
Taper: .001
PISTONS:
Clearance: .0015-.0030
PISTON RING: Compression: Groove Clearance: .0012-.0032 Gap: .010-.020 (top) .010-.025 (2nd) Oil: GC: .002-.007 Gap: .015-.055 PISTON PIN: Diam: .9270-.9273 Piston Clearance: .0002-.0007 Rod Fit: .0008-.0016 Interference
CRANKSHAFT:
MAIN JOURNAL: Diam: #1 2.4484-2.4493
#2 #3 2.4481-2.4490
#4 2.4479-2.4488
Taper: .001 max
Out of Round: .001 max
MAIN BRG. CLEARANCE: #1 .0010-.0015 #2#3 .0010-.0025 #4 .0025-.0035
CRANK END PLAY: .002-.006
CRANKPIN: Diam: 2.2487-2.2497
Taper: .001 max
OOR: .001 max
ROD CLEARANCE: .0013-0030
SIDE CLEARANCE: .006-.014
CAMSHAFT:
LIFT +- .002 Intake .357 Exhaust .390 Journal Diam: 1.8682-1.8692 End Play .004 -.012
VALVE SYSTEM:
Lifter Hydraulic Rocker ratio 1.5:1
Lash Adj. One turn down from zero Face Angle 45 deg.
Seat Angle 46 deg.
Runout .002 max
Seat Width 1/16 to 1/32 Stem clearance .0010-.0028 Spring length 2.03 Valve Spring Pres. 76-84 lbs @ 1.70 in Closed 194-206 lbs @ 1.25 in
Open Installed height 1 23/32
Valve Spring Damper: Free Length 1.86 # coils 4
The stuff that finally worked for me was Loctite 567...It's a "white" loctite that withstands over 400 degrees F.....Yeah, my head studs leaked the first time around using a "teflon" based brush-on stuff....It was also white but it definitely didn't work.....I ran the motor for about an hour (never drove it), then yanked it and disassembled it to check for damage....when I pulled the main caps, one of them had some droplets of water around the bearing area....that ended up being the ONE splayed hole that made it through to the jacket....so I found it by accident you could say because I tore the motor apart for having run the motor with leaky "head" studs....then I plastigaged the rods and mains and found the clearances were way off spec, so back to a "different" machine shop for some crank cutting.....all this on a "standard" uncut 4.3 crank...I never even brought these issues to the first shop's attention, because they screwed up to begin with....why take the motor back to someone that has screwed up in the first place already...I found out the hard way that these motors have to be within certain specs/clearances if you expect them to live....well, at least my motor didn't blow up or get damaged....never trust any machine shop's work when they give you assembled shortblock....CHECK THEIR WORK before you assemble the motor....get a qualified person to pop off the rod and main caps and plastigage them at the very least...whoever assembles the motor is ultimately responsible if the motor fails for not having checked the machine shop's work before assembly in the first place...you can avoid all the crap I went through before the motor is in the truck running and you find out you don't have any oil pressure or you spin bearings.... below are the recommended specs you should give to the machine shop when they work on your motor...These motors should not be treated as regular 4.3's....
Type: V6
Disp.: 262 C.I. (4.3L)
Horsepower: 280 BHP @ 4400 (Syclone) 285 BHP @4400 (Typhoon)
Torque: 350 lb-ft @ 3600 (Syclone) 350 lb-ft @ 3600 (Typhoon)
RPO: LB4
Bore: 4.00
Stroke: 3.48
Comp. Ratio: 8.35:1
Firing Order: 1-6-5-4-3-2
Oil Pres. (Min) 6 psi@ 1000 RPM, 18 psi@ 2000 RPM, 24 psi@ 4000 RPM
CYLINDER BORE:
Diameter: 3.9995-40025
Out of
Round: .001 (production) .002 (service)
Taper: .001
PISTONS:
Clearance: .0015-.0030
PISTON RING: Compression: Groove Clearance: .0012-.0032 Gap: .010-.020 (top) .010-.025 (2nd) Oil: GC: .002-.007 Gap: .015-.055 PISTON PIN: Diam: .9270-.9273 Piston Clearance: .0002-.0007 Rod Fit: .0008-.0016 Interference
CRANKSHAFT:
MAIN JOURNAL: Diam: #1 2.4484-2.4493
#2 #3 2.4481-2.4490
#4 2.4479-2.4488
Taper: .001 max
Out of Round: .001 max
MAIN BRG. CLEARANCE: #1 .0010-.0015 #2#3 .0010-.0025 #4 .0025-.0035
CRANK END PLAY: .002-.006
CRANKPIN: Diam: 2.2487-2.2497
Taper: .001 max
OOR: .001 max
ROD CLEARANCE: .0013-0030
SIDE CLEARANCE: .006-.014
CAMSHAFT:
LIFT +- .002 Intake .357 Exhaust .390 Journal Diam: 1.8682-1.8692 End Play .004 -.012
VALVE SYSTEM:
Lifter Hydraulic Rocker ratio 1.5:1
Lash Adj. One turn down from zero Face Angle 45 deg.
Seat Angle 46 deg.
Runout .002 max
Seat Width 1/16 to 1/32 Stem clearance .0010-.0028 Spring length 2.03 Valve Spring Pres. 76-84 lbs @ 1.70 in Closed 194-206 lbs @ 1.25 in
Open Installed height 1 23/32
Valve Spring Damper: Free Length 1.86 # coils 4
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