are pulleys worth it?
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Joined: Sep 2008
Posts: 622
From: Québec city
Same here on over 8 different Honda's (track cars and DD's) for the last 10+ years and not a single problem. People will always disagree on this topic. I prefer to draw from my own actual real life experience 
Edit: We're also talking about a fit here I mean it's a 1.5 ltr engine that has a short crankshaft. I just don't see how there would be a real problem. Now is it worth it? Well that all depends on the owner. Realize that your audio, climate controls and other accessories will be affected to some degree. I personally will be adding them to my Fit.
Edit: We're also talking about a fit here I mean it's a 1.5 ltr engine that has a short crankshaft. I just don't see how there would be a real problem. Now is it worth it? Well that all depends on the owner. Realize that your audio, climate controls and other accessories will be affected to some degree. I personally will be adding them to my Fit.
Marko!!
Last edited by DOHCtor; Nov 30, 2010 at 06:12 PM.
You CAN have sex with a Somali prostitute and you might get away with it for several years, but should you? 
This is for helping the engine deal with harmonics and vibration, and has nothing what so ever to do with balancing, internal or otherwise.
Now the heaviest end of the crank is going to act as a node. This would be the flywheel or torque converter side. The lighter side will experience the most flexing. Which is why you need the wave(s) traveling to it dampened. This is to prevent wave peaks from coinciding and adding to eachother in the course of typical resonance.
Now most, if not all, OE engines like those of toyota/lexus hybrids don't have any accessories that require a crank pulley (they are electric) but they still run dampers.
From another engineer on a private tuning forum:
Think about what underdriving will do to your belt driven fluid pumps and their effectiveness as well as what underdriving the alternator will do to your voltage sensitive fuel system, injectors especially.
Also, keep in mind that many tracks, circuit, drag what have you.. require an SFI approved damper like an ATI or Fluidampr unit in order to pass tech, some drag strips that are more relaxed may only check if you are expecting to run a sub 9.99sec quarter.
So, we know there are some potential negatives to not having a damper, what are the positives?
Inline 4cyl cranks snap too guys. There is no way to make a crank so stiff and sturdy that these forces are negated or elminated. We have a 3.5" (89mm) crank, that allows for alot of leverage.
It takes ~0.01" deflection before your crank hits the bearings. IMHO, and it is an educated one, this is a poor solution for power that could be better remedied elsewhere in the rotating assembly.
Are these pulleys so attractive because they are cheap?
Formula Ford's regulations under section D.3c6 states:
rings.
This is for helping the engine deal with harmonics and vibration, and has nothing what so ever to do with balancing, internal or otherwise.
Now the heaviest end of the crank is going to act as a node. This would be the flywheel or torque converter side. The lighter side will experience the most flexing. Which is why you need the wave(s) traveling to it dampened. This is to prevent wave peaks from coinciding and adding to eachother in the course of typical resonance.
Now most, if not all, OE engines like those of toyota/lexus hybrids don't have any accessories that require a crank pulley (they are electric) but they still run dampers.
From another engineer on a private tuning forum:
M. Campbell - Its about negating the 'whipping', or recoil, of the crank arm right after the power stroke. As you progress in rpms, those recoil events coincide with other recoil events; therefore, resonance of the crankarm movements is obtained.
Weigh the trade off from power loss to crank flex carefully. "Risk before reward", yes, but what realistically is the reward. KISS.
Weigh the trade off from power loss to crank flex carefully. "Risk before reward", yes, but what realistically is the reward. KISS.
Also, keep in mind that many tracks, circuit, drag what have you.. require an SFI approved damper like an ATI or Fluidampr unit in order to pass tech, some drag strips that are more relaxed may only check if you are expecting to run a sub 9.99sec quarter.
So, we know there are some potential negatives to not having a damper, what are the positives?
Inline 4cyl cranks snap too guys. There is no way to make a crank so stiff and sturdy that these forces are negated or elminated. We have a 3.5" (89mm) crank, that allows for alot of leverage.
It takes ~0.01" deflection before your crank hits the bearings. IMHO, and it is an educated one, this is a poor solution for power that could be better remedied elsewhere in the rotating assembly.
Are these pulleys so attractive because they are cheap?
Formula Ford's regulations under section D.3c6 states:
D.3. Honda Fit 1500 (L15A7) Engine
a. General
1. No modifications to this engine are allowed except where specifically
authorized within these rules. This includes, but is not limited to, all fuel
injection and engine management components, electrical, cooling and
lubrication systems. All systems are subject to test procedures and
must conform to OEM specifications as stated in the Honda Fit factory
service manual, Honda PN 61TK600 and all superseding years, or as
specified in these rules. The factory service manual or its equivalent is
required to be in the possession of each entrant. The manual may be
the form of printed material, microfiche, CDs, DVDs and/or Internet
access to manufacturer sponsored web-based databases.
2. Permitted engine maintenance includes the replacement, but not
modification, of external engine and engine systems parts.
3. All rubber fluid lines may be replaced with braided metal-covered
(Aeroquip type) lines. Hose clamps maybe installed on the rubber oil
lines.
4. No balancing, lightening, polishing or other modification of moving
parts of the engine is permitted.
5. Only stock Honda manufactured gaskets and seals as specified in the
Honda Fit factory service manual are permitted (Including, but not
limited to, head gasket, intake runner gaskets and O-rings, restrictor
plate gasket, and intake and exhaust gaskets).
6. For all Honda part numbers in these specifications, superceding part
numbers are considered equivalent.
a. General
1. No modifications to this engine are allowed except where specifically
authorized within these rules. This includes, but is not limited to, all fuel
injection and engine management components, electrical, cooling and
lubrication systems. All systems are subject to test procedures and
must conform to OEM specifications as stated in the Honda Fit factory
service manual, Honda PN 61TK600 and all superseding years, or as
specified in these rules. The factory service manual or its equivalent is
required to be in the possession of each entrant. The manual may be
the form of printed material, microfiche, CDs, DVDs and/or Internet
access to manufacturer sponsored web-based databases.
2. Permitted engine maintenance includes the replacement, but not
modification, of external engine and engine systems parts.
3. All rubber fluid lines may be replaced with braided metal-covered
(Aeroquip type) lines. Hose clamps maybe installed on the rubber oil
lines.
4. No balancing, lightening, polishing or other modification of moving
parts of the engine is permitted.
5. Only stock Honda manufactured gaskets and seals as specified in the
Honda Fit factory service manual are permitted (Including, but not
limited to, head gasket, intake runner gaskets and O-rings, restrictor
plate gasket, and intake and exhaust gaskets).
6. For all Honda part numbers in these specifications, superceding part
numbers are considered equivalent.
b. Block
1. The only permitted cylinder block is Honda PN: 11000-RP3-810
2. Honing of cylinders is permitted to a maximum diameter of 73.065 mm
(2.8766”). Fitting of cylinder sleeves is prohibited. Re-boring to over
size is prohibited.
3. Block must use stock main bearing caps, girdle and hardware as
supplied.
1. The only permitted cylinder block is Honda PN: 11000-RP3-810
2. Honing of cylinders is permitted to a maximum diameter of 73.065 mm
(2.8766”). Fitting of cylinder sleeves is prohibited. Re-boring to over
size is prohibited.
3. Block must use stock main bearing caps, girdle and hardware as
supplied.
c. Crankshaft
1. The stock Honda Fit crankshaft, Honda PN: 13310-RB1-000, must be
used with no modifications allowed.
2. Minimum weight: 27. 6 lbs.
3. Maximum stroke at piston: 89.4mm (3.520”)
4. Main and rod bearings must not be modified in any way. OEM bearings
must be used from within the standard range as allowed in the Honda
Fit factory service manual.
5. The crank pulsar must not be altered in any way.
6. The crank pulley/balancer must not be altered or modified in any way.
a. Minimum weight: 3.90 lbs.
b. Honda PN: 13810-RB0-003.1. The stock Honda Fit crankshaft, Honda PN: 13310-RB1-000, must be
used with no modifications allowed.
2. Minimum weight: 27. 6 lbs.
3. Maximum stroke at piston: 89.4mm (3.520”)
4. Main and rod bearings must not be modified in any way. OEM bearings
must be used from within the standard range as allowed in the Honda
Fit factory service manual.
5. The crank pulsar must not be altered in any way.
6. The crank pulley/balancer must not be altered or modified in any way.
a. Minimum weight: 3.90 lbs.
d. Connecting Rods
1. Stock Honda Fit connecting rod must be used PN: 13320-RB1-000.
2. Minimum connecting rod weight: To be supplied by HPD.
3. Connecting rod length center to center: To be supplied by HPD.
e. Pistons
1. Honda Fit OEM standard size pistons, PN: 13010-RB1-000, must be
used.
2. The use of over size pistons is not permitted.
3. Piston dimensions and weights:
a. Maximum standard piston diameter, measured at a point 16mm
from the bottom of the skirt: 72.990mm (2.8736”).
b. Centerline of wrist pin to crown: To be supplied by HPD.
c. Overall height: To be supplied by HPD.
d. Minimum weight: To be supplied by HPD.
e. Weight of piston pin: 67 grams.
4. Piston Rings must be as used in the Fit engine. The only modification
allowed is ring end gap width. Two compression rings and one 3 piece
oil control ring must be used.
a. The standard ring pack PN 13011-RB1-004 (Riken) or 13011-RB1-
006 (Nippon).
b. No modification of the piston is permitted for the installation of
2. Minimum connecting rod weight: To be supplied by HPD.
3. Connecting rod length center to center: To be supplied by HPD.
e. Pistons
1. Honda Fit OEM standard size pistons, PN: 13010-RB1-000, must be
used.
2. The use of over size pistons is not permitted.
3. Piston dimensions and weights:
a. Maximum standard piston diameter, measured at a point 16mm
from the bottom of the skirt: 72.990mm (2.8736”).
b. Centerline of wrist pin to crown: To be supplied by HPD.
c. Overall height: To be supplied by HPD.
d. Minimum weight: To be supplied by HPD.
e. Weight of piston pin: 67 grams.
4. Piston Rings must be as used in the Fit engine. The only modification
allowed is ring end gap width. Two compression rings and one 3 piece
oil control ring must be used.
a. The standard ring pack PN 13011-RB1-004 (Riken) or 13011-RB1-
006 (Nippon).
b. No modification of the piston is permitted for the installation of
rings.
Last edited by DiamondStarMonsters; Dec 1, 2010 at 01:09 AM.
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