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  1. #1
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    Default Shovelhead bent pushrods, blowing oil, what's up?

    I rebuilt my 74/74 front the cases up with all new parts - S&S rods, new bearings, wiseco pistons/pins, .10 overbore, new S&S heads, S&S valve train, oil pump, the whole shebang. Bike was rippin but after a ride last weekend a friend said he was catching white smoke between my 2-1 downshifts.

    I initially thought the bike was loading up on decel producing the smoke between downshifts and attributed it to jetting, but there's a wet oily residue in the pipes, and the next day the bike died due to wet fouling and I had to push. My first thought is valve stem seals, but on new heads I was skeptical, as the bike won't puff when I rev or otherwise smoke as it runs, only during decel.

    I decide to do a comp and leakdown test for shits and the numbers weren't good. Pulled the pipes and raw oil is leaking past the exhaust gaskets. Pulled the pushrod covers and discovered both of the pushrods on the front cylinder are bent, and at least one on the rear. Comp test and leakdown test with pushrods removed produced much better numbers.

    I ordered a new set of pushrods but I'm wondering if these two problems are related. If a pushrod adjustment is too tight, is it possible the valve is hanging open just enough to create some kind of vacuum that's pulling oil past the stem seals? - though I suspect an engine couldn't run in this condition. I'm using an Andrews B2 cam which requires at least .505 spring travel - the S&S heads can handle up to .590 of spring travel, so my cam and springs are within safe operation limits. Perhaps too tight of an adjustment whacked the stem seals?

    Bike was powerful and the motor/top end was very quiet. One kick bike w the super E and hunt mag. It was the wet pipes that had me digging...

    Any thoughts from you guys before I start pulling this thing back apart?
    Last edited by Blackbetty; 10-12-2016 at 12:30 PM.

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    Can ya lay your hands on a bore scope..... I would like to see what the cylinder walls look like...???

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    Another thing to consider: did you (or the person who did your heads) check clearances for the valves? I know you said the heads are s&s, and are set up for up to .590 lift, but TDC lifts can vary, and sometimes you will have valve to valve clearances that are too tight, and it is always a good idea to check all of your clearances (valve to piston & valve to valve.) I apologize if I am stating the obvious to you, just thought I would pass along my thoughts on your situation.

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    I think I'm just going to pull the heads completely. At the expense of head and rocker gaskets I can determine if this is a ring or valve stem issue in one shot. The guys at S&S tell me there isn't any reason a pushrod should bend unless it's met with mechanical interference and he's worried valves have kissed. WillSCB - I did not check clearances and this is what S&S is worried about. The cam I selected is designed to work around stock springs though, and those have less spring travel than S&S. But I hardly see how an engine that has made valve contact would run at all, and mine, even w the oil burning and bent pushrods, was starting easily.

    The bores are fresh though, .10 overbore. New pistons and wristpins. I did the leakdown on the front cylinder with the pushrods out and had less than 5% leakage - but once the heads are off I'll know for sure where the motor is drawing in oil. There's maybe 3 hours run time on this engine since I rebuilt it, so I've been going super easy on it during break in...
    Last edited by Blackbetty; 10-12-2016 at 1:27 PM.

  5. #5
    rocksmearer
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    I know S&S is quality stuff, that sounds exactly like what happened on my shovel when I lost a valve guide though. will be interesting to see what the actual cause was when you pull the heads.
    Last edited by rocksmearer; 10-12-2016 at 1:52 PM.

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    Isn't anyone left on JJ to answer this question??????????? I see you posted it first this morning on Jockey the same question with still no answers............That place is DEAD...........

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    That first 50 miles is tough to do.....
    I'm thinking that a piston had a seizure.... That along wont explain why the pushrods got bent...

    S&S heads are made with a smaller O.D. exhaust valve head....
    Take a Bad Boy cam to get the valves to play tad....

    Sometimes a hyd. lifter will pump up to where there will be more lift, that mostly happens at high engine speeds....

    Quote Originally Posted by Tattooo View Post
    Isn't anyone left on JJ to answer this question?
    I would be afraid to put much faith in what they would tell ya....
    Might tell ya the fix would be to pull the breather gear out .. !!!!

    Last edited by Dragstews; 10-12-2016 at 2:16 PM.

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    I haven't run the motor at very high RPMs. Hell, I haven't even really put it in 4th. Just been putting around town break in miles on it.

    I haven't noticed pinging and the engine was running strong - I'm really hoping it wasn't a seizure as the leakdown numbers were good.

    I should note all this testing has been on the front cylinder, and strangely, I can't seem to get out the rear cylinder pushrods despite being collapsed all the way...

    this fuckin thing

    And yes, I figured someone on JJ would have chimed in quick. Lost cause I guess on that site these days.

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    Quote Originally Posted by Blackbetty View Post
    And yes, I figured someone on JJ would have chimed in quick. Lost cause I guess on that site these days.


    JJ is a joke these days............. I hope the Canadians that bought it was looking for somewhere to loose money??????????????

    I'm with Jesse on this......... I think your clearances were to close on the pistons.......... Did you let it idle much before you rode it?????????

  10. #10

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    As I understand it some aftermarket shovel pushrods are different length for intake and exhaust.
    Maybe yours are , and are wrong way around.
    Might check that, be a cheap fix.

  11. #11
    rocksmearer
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    Quote Originally Posted by johno View Post
    As I understand it some aftermarket shovel pushrods are different length for intake and exhaust.
    Maybe yours are , and are wrong way around.
    Might check that, be a cheap fix.
    I'm thinking it would have bent a pushrod on the first kick if that were the case. your 2 rear are the same length intake is slightly longer, exhaust the longest. I think a guy would be hard pressed to adjust the tappets and not notice something wrong

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    Quote Originally Posted by rocksmearer View Post
    I'm thinking it would have bent a pushrod on the first kick if that were the case. your 2 rear are the same length intake is slightly longer, exhaust the longest. I think a guy would be hard pressed to adjust the tappets and not notice something wrong
    Aaaaaaaa ..... Well, close but no cigar.....

    The two intakes are the same and the shortest ....
    Next long one is the rear exhaust, last one is the longest and is the front exhaust .....

  13. #13
    rocksmearer
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    Quote Originally Posted by Dragstews View Post
    Aaaaaaaa ..... Well, close but no cigar.....

    The two intakes are the same and the shortest ....
    Next long one is the rear exhaust, last one is the longest and is the front exhaust .....
    lmfao, thought that response through didn't I! It's been a minute since I fucked with my pushrods and well, I've had a few beers. Good save on the misinformation train. But as I said, while your adjusting your tappets you would for sure notice something wasnt right.

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    It's all good....
    Ya had the count right ....

    I would hate to adjust the pushrods on this bike.....

    .../// https://youtu.be/Ys7lrX107xE \\\...

    Take a week ..... !!!
    (Besides, don't think I can count that high unless I take off my shoes..!!)
    Last edited by Dragstews; 10-12-2016 at 9:27 PM.

  15. #15
    rocksmearer
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    Quote Originally Posted by Dragstews View Post
    It's all good....
    Ya had the count right ....

    I would hate to adjust the pushrods on this bike.....

    .../// https://youtu.be/Ys7lrX107xE \\\...

    Take a week ..... !!!
    (Besides, don't think I can count that high unless I take off my shoes..!!)
    I don't think I could afford all the rhinestoned pocketed out jeans required in ones wardrobe that it would take to pull into the dealership.... much less the bike. can you imagine how fast it would make you the local H.O.G. chapter president though? fuck yes! another round of wine spritzers for all my subordinates!

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    Hell .... That Ol Boy ain't pulling into a Dealership with four Rev-Tech motors.... He would get stoned by the service dept. before he got within 20' of the door..... !!!



    (Unless Bob Marley was the service manager..???
    Come to think about it, he would still get stoned !! .. A lot less painful)

    Last edited by Dragstews; 10-12-2016 at 10:40 PM.

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    OK boys I got out back and pulled the heads. It wasn't doom and gloom as far as I can tell....the oil problem was the head gaskets. I used MLS cometic gaskets and both cylinders were suckin in oil from the drain back hole. I've used these gaskets on 3 different motors before, but never a shovel, and I'm puzzled as to why they failed. I torqued them in sequence and to spec, and retorqued the heads after the first few rides. Is there a better head gasket to use on these motors? I was considering trying the embossed james gaskets with the fire ring.





    Moving to the bent pushrod scenario....

    The cylinder walls are perfect, they still look new front to back, like a motor with just a few hours. The pistons are clean and show no sign of valve contact. The heads also look good with no evidence of interference:









    Push rods were installed correctly (two short at intake, longest at front exhaust), but as I mentioned, the rears only came out when I pulled the head.

    I went ahead and pulled the rocker boxes and noticed nothing out of the ordinary - I'm using the roller rockers but clearance in the box is fine as there's no evidence of interference. When I built the boxes I used Jims shafts, S&S rollers, and OEM boxes. New rocker spacers and shims, all from Eastern. I spent a ton of time setting up my rocker boxes when I built up the motor to achieve an endplay number between .008-.010" - the rockers move freely and the rollers aren't galled. There are no broken valve springs.

    I think I'm going to pull the lifter blocks next and see if something is weird in the cam chest. But for now I'm kinda lost as to the why the pushrods would bend. Do you all think I should keep going and pull the valves to check seals/guides?
    Last edited by Blackbetty; 10-13-2016 at 8:51 AM.

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    You are lucky.......... Make sure the head and cylinder is flat........... My 79 FXH did the same thing and it was the head........ Put your head back on the cylinder with no gasket and see if you can rock it............. Mine did.........

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    Usually when I install these gaskets on a motor, the rivets holding the layers together will clear everything. But when I put these on the shovel, I noticed the head pushes the riveted ears down. I wonder if that causes the gasket to settle in incorrectly? I've seen guys cut these ears off before installation - maybe it's necessary when installing MLS on shovels, but man, what a pain in the ass lining everything up. I'd rather just try the james gaskets instead.

    I'll lay the head on the cylinder without a gasket and check for flatness. Hopefully I'll not have any issues being heads are brand new....

    Edit - I spoke with S&S and the have no idea. I called Andrews and the guy was telling me to check coil bind, because the B2 cam is high lift for shovel standards. So I guess I'll be checking coil bind next.

    Edit #2 - I did more research and found this:

    B2 Grind Cam
    Street/drags: More mid range and high-end power, smooth idle
    Best cam for modified 74/80 inchers and small strokes
    Spring spacing required

    I built this motor around the S&S heads, which has way more spring travel than stock heads. I figured this would allow the best clearance - now I'm reading up about this cam on sites outside of Andrews, and it's saying spring spacing required.

    Then I found andrews part # 276150 - upper valve spring collars that add an additional .060 spring travel and with the following note:

    Note: Recommended for # 212353 and # 212358 B Grind.

    The B2 is 212353.

    I'm thinking this is indeed spring bind. I'm take some measurements and see if I can't fix this with the help of these collars.
    Last edited by Blackbetty; 10-13-2016 at 9:27 AM.

  20. #20
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    Oil getting into the burn from the top-end return hole in the gasket ... ????????

    I'm not seeing that.....
    Your heads are new from S&S .... They do a good job of not selling warped gasket surfaces out of the box ....

    Those MSL gasket work well too.... The rivets sometimes do get in the way.....
    The James Fire-ring gaskets work just as well with a bit less fuss installing em.

    Now this is what I do see ..... (Or in this case don't see)

    Click image for larger version. 

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    Where's the Cross-Hatch ...???
    I know it's a bit hard to get a good photo of the bore with a flash .... But dang what I think I'm seeing is a flat cross-hatch and very little of it....

    This is what we should be looking at down in your bore.....



    Also when S&S heads are being used I would use the lower number for torque, their thread inserts are not casted in like the Oem heads have, going to max torque could pull them from the parent metal ....

    When you did your Leak-Down test did you have the timing plug pulled out from the case.... If you did, and that gasket was at fault you would have heard air escaping from the timing hole....

    I'm thinking that the lack of a good Cross-hatch is where the oil is coming from....
    I could be wrong, but that's what I'm seeing in your photo...

    On the coil-bind ....
    Take a hard look at the valve springs on the inside of the spring wire....
    There will be witness marks on the coils touching together....

    Best not to be guessing when packing the springs for a given cam grind...
    Trock Cycle valve spring checker comes in handy as Tits on a Milk Cow for doing the job right.....

    Last edited by Dragstews; 10-21-2016 at 2:43 PM.

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