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pushrod rubbing heads grind for clearance??? #183571 01/04/09 01:29 PM 01/04/09 01:29 PM
Joined: Aug 2003 Posts: 4,671 On the parachute mount N n20mstr OP master
n20mstr OP master N Joined: Aug 2003 Posts: 4,671 On the parachute mount	Upon disassembly, im finding that even thought the pushrods have .050 or so clearance, in some spots they are slightly rubbing. I see a very slight polishing on the pushrods and the same on the heads. The pushrods are rotating because its all the way around in one spot and very slight(Indy 440-1's and Smith bro pushrods) Now im tempted to grind the heads just a little in the polished spots, but im reconsidering that the pushrods need that little "support" They dont touch when the engine is on the stand...they have clearance (I already ground the heads and block for the clearance) Should i touch them up or leave it?? No problems so far roughly 200 passes like this ....BAD A$$ STREET CAR.....

Re: pushrod rubbing heads grind for clearance??? [Re: n20mstr] #183572 01/04/09 01:34 PM 01/04/09 01:34 PM
Joined: Jul 2005 Posts: 8,647 ELYRIA,OH B blownzoom440
blownzoom440 B Joined: Jul 2005 Posts: 8,647 ELYRIA,OH	we would realy have to see how much it is rubbing but i say leave it.

Re: pushrod rubbing heads grind for clearance??? [Re: n20mstr] #183573 01/04/09 01:38 PM 01/04/09 01:38 PM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	How thick of wall and diameter are your P/Rs

Re: pushrod rubbing heads grind for clearance??? [Re: MR_P_BODY] #183574 01/04/09 01:41 PM 01/04/09 01:41 PM
Joined: Oct 2004 Posts: 5,617 long island NY A Ari440 master
Ari440 master A Joined: Oct 2004 Posts: 5,617 long island NY	are thet 3/8ths or 7 1/6ths pushrods they should not be touching or rubbing 1.39 9.85 - 137 mph

Re: pushrod rubbing heads grind for clearance??? [Re: MR_P_BODY] #183575 01/04/09 01:44 PM 01/04/09 01:44 PM
Joined: Aug 2003 Posts: 4,671 On the parachute mount N n20mstr OP master
n20mstr OP master N Joined: Aug 2003 Posts: 4,671 On the parachute mount	Quote: How thick of wall and diameter are your P/Rs 3/8 im not sure of the wall, maybe .080?? All they put in the bag is a business car with the dimensions written on it ....BAD A$$ STREET CAR.....

Re: pushrod rubbing heads grind for clearance??? [Re: n20mstr] #183576 01/04/09 02:04 PM 01/04/09 02:04 PM
Joined: Aug 2003 Posts: 43,099 Bend,OR USA C Cab_Burge I Win
Cab_Burge I Win C Joined: Aug 2003 Posts: 43,099 Bend,OR USA	Did you check the clearances in the motor cold and all the way through the lift cycle opening and closing? If not do that first, if the ones rubbibg clear then the pushrods are probaly flexinf enough in the problem spots to rub. Manton syas there is nothing wrong with aving extra pushrod support as long as the motor isn't making metal or killing the pushrod cups due to the pushrod not allowing oil into the cup and adjuster seat I have found ut the hard way that you don't want a Hemi pushrod rubbing becuase it can kill the rocker end of the pushrods do to lack of oil in the pushrod cup. I had to replace three exhaust single tapered pushrods in one of my customers motors, at $24.00 a piece, back in the mid 1990 due to my allowing thme to rub to much there are a lot of pushrods running in motors all across the country that are living well without causing problems, they shine where they rub Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)

Re: pushrod rubbing heads grind for clearance??? [Re: Cab_Burge] #183577 01/04/09 02:08 PM 01/04/09 02:08 PM
Joined: Aug 2003 Posts: 4,671 On the parachute mount N n20mstr OP master
n20mstr OP master N Joined: Aug 2003 Posts: 4,671 On the parachute mount	Quote: Did you check the clearances in the motor cold and all the way through the lift cycle opening and closing? If not do that first, if the ones rubbibg clear then the pushrods are probaly flexinf enough in the problem spots to rub. Manton syas there is nothing wrong with aving extra pushrod support as long as the motor isn't making metal or killing the pushrod cups due to the pushrod not allowing oil into the cup and adjuster seat I have found ut the hard way that you don't want a Hemi pushrod rubbing becuase it can kill the rocker end of the pushrods do to lack of oil in the pushrod cup. I had to replace three exhaust single tapered pushrods in one of my customers motors, at $24.00 a piece, back in the mid 1990 due to my allowing thme to rub to much there are a lot of pushrods running in motors all across the country that are living well without causing problems, they shine where they rub I have checked and they are not rubbing on the engine stand going through the lift cycle... They are "slightly" rubbing because yes they just have that Polished look where they are tocuhing, not much at all im sure ....BAD A$$ STREET CAR.....

Re: pushrod rubbing heads grind for clearance??? [Re: n20mstr] #183578 01/04/09 02:15 PM 01/04/09 02:15 PM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	I have checked and they are not rubbing on the engine stand going through the lift cycle... They are "slightly" rubbing because yes they just have that Polished look where they are tocuhing, not much at all im sure Sounds like they just arent strong enough and are deflecting to much, normally .050 thru the whole range is plenty

Re: pushrod rubbing heads grind for clearance??? [Re: MR_P_BODY] #183579 01/04/09 02:17 PM 01/04/09 02:17 PM
Joined: Aug 2003 Posts: 4,671 On the parachute mount N n20mstr OP master
n20mstr OP master N Joined: Aug 2003 Posts: 4,671 On the parachute mount	Quote: I have checked and they are not rubbing on the engine stand going through the lift cycle... They are "slightly" rubbing because yes they just have that Polished look where they are tocuhing, not much at all im sure Sounds like they just arent strong enough and are deflecting to much, normally .050 thru the whole range is plenty Maybe i really DONT have .050??? I guess im grindind and checking LOL LOL ....BAD A$$ STREET CAR.....

Re: pushrod rubbing heads grind for clearance??? [Re: n20mstr] #183580 01/04/09 05:27 PM 01/04/09 05:27 PM
Joined: Aug 2004 Posts: 3,333 MARYLAND 69Cuda340S master
69Cuda340S master Joined: Aug 2004 Posts: 3,333 MARYLAND	If its a hydraulic cam you may need to install check springs because the lifter may not be pumped up when the engine is on the stand.

Re: pushrod rubbing heads grind for clearance??? [Re: 69Cuda340S] #183581 01/04/09 06:25 PM 01/04/09 06:25 PM
Joined: Nov 2004 Posts: 3,544 Syracuse,NY CompWedgeEngines master
CompWedgeEngines master Joined: Nov 2004 Posts: 3,544 Syracuse,NY	Normally "slight" rubbing ( as you seem to be explaining ) isnt a huge issue. I am a Manton WD dealer and they recommend only .010 clearance and many times the slight rubbing is fine. I used to over-clearance these areas but have since changed my ways and found it to be better.Its not a problem to have that support, but I would also guess that a thicker walled pushrod could be a good thought in your case knowing somethings about your combo and ET as you have posted before. RIP Monte Smith Your work is a reflection of yourself, autograph it with quality. WD for Diamond Pistons,Sidewinder cylinder heads, Wiseco, K1 rods and cranks,BAM lifters, Morel lifters, Molnar Technologies, Harland Sharp, Pro Gear, Cometic, King Engine Bearings and many others.

Re: pushrod rubbing heads grind for clearance??? [Re: CompWedgeEngines] #183582 01/04/09 06:29 PM 01/04/09 06:29 PM
Joined: Jan 2003 Posts: 19,355 Las Vegas Al_Alguire I Live Here
Al_Alguire I Live Here Joined: Jan 2003 Posts: 19,355 Las Vegas	I agree slight rubbing is not an issue. .050" is plenty of clearance for a pushrod, maybe even a bit more than necessary IMO. If it spins over fine on the stand and has that much clearance dont worry about it. Many would argue that the slight rubbing is acting like a "guide plate" of sorts to help stabilize the pushrod. I tend to agree. If it is only slight rubbing dont sweat it. "I am not ashamed to confess I am ignorant of what I do not know." "It's never wrong to do the right thing"

Re: pushrod rubbing heads grind for clearance??? [Re: n20mstr] #183583 01/04/09 08:27 PM 01/04/09 08:27 PM
Joined: Apr 2008 Posts: 20 wilson nc J jpm1916 member
jpm1916 member J Joined: Apr 2008 Posts: 20 wilson nc	how much spring pressure may need .120 or 135 wall thick pushrods

Re: pushrod rubbing heads grind for clearance??? [Re: Al_Alguire] #183584 01/04/09 08:43 PM 01/04/09 08:43 PM
Joined: Jan 2003 Posts: 6,591 Canton, Ohio S Sport440 master
Sport440 master S Joined: Jan 2003 Posts: 6,591 Canton, Ohio	If its only "slightly" rubbing as desccribed, and not producing chips, consider it a guide plate. mike

Re: pushrod rubbing heads grind for clearance??? [Re: Sport440] #183585 01/04/09 10:39 PM 01/04/09 10:39 PM
Joined: Aug 2003 Posts: 4,671 On the parachute mount N n20mstr OP master
n20mstr OP master N Joined: Aug 2003 Posts: 4,671 On the parachute mount	i read the info on Mantons site, i will double check my clearance while assembling the engine this time, but yea its rubbing VERY little, and even at that, its only on the intakes and all its doing is putting a slight polish on the pushrods. I remmeber having smallblocks that had the large cork gastkets rubbing the pushrods and that left more of a mark on there than this...Thanks for all the replies ....BAD A$$ STREET CAR.....

Re: pushrod rubbing heads grind for clearance??? [Re: n20mstr] #183586 01/04/09 10:44 PM 01/04/09 10:44 PM
Joined: Nov 2004 Posts: 6,890 North Alabama M Monte_Smith master
Monte_Smith master M Joined: Nov 2004 Posts: 6,890 North Alabama	It's pretty simple. If you have plenty of clearance and they don't rub when you roll it over, your pushrods are not good enough. Now as mentioned, it will probably not hurt a thing, other than cost you power. Valvetrain deflection is one of the biggest power robbers there are. There is a reason that really high HP engines have pushrods that look like tree trunks and use large cam cores. Monte

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