1965 273 commando solid cam lash specs ?

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stroker402

stroker402

1968 dart GTS convertible
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Could someone please tell me what the valve lash specs are on a 1965 273 commando solid cam engine please ?
Also the torque spec on the rocker arm bolts ?
Thanks ! greatly appreciated.
went to go an install a different intake and found two pushrods bent.. did not even notice any difference the way the engine ran. to ticking or rough idle....go figure .
this little engine loves to rev 6500 all day ... maybe too high for it ! That low first gear tach up so fast ........ need a rev limiter i guess.
Thanks !
 
Commando Cam:

Lift
Intake Exhaust
0.425" 0.425"


Duration
Intake Exhaust
248° 248°

I have read the torque on the rocker arms to be 25 ft/lbs and 10 ft/lbs and 17 ft/lbs in several sources. I will look in the blue manual again when I get a chance.
 
.013 intake .021 exhaust set them hot. tmm
 
Torque specs on rocker shaft bolts are 15 ft lbs...that comes from a 67 service manual, I believe if the bolts are 5/16 its 15 ft lbs. I almost buggered dads as I looked in my 69 manual and it said 30 ft lbs...WRONG for 67 anyway. Here is a link to a thread I started...hope you learn from my mistakes LOL
http://www.forabodiesonly.com/mopar/showthread.php?t=183564
 
Thanks guys !
Got the new pushrods in then torqued the rocker arms down to 17 ft lbs. small 5/16 bolt .
when I adjust the valve lash I did it this way which i found on the internet in a few places.

adjust the Intake valve when exhaust valve is starting to open.
adjust the exhaust valve when the intake is starting to close.
everything looks Good to go!

Ice cold engine setting intake at .012 and exhaust at .019
hot specs are as mentioned above .013 and .021 .
I think that should be fine for a cold engine setting .

I think someone might have been there previously setting those valves the wrong way.. they were not in specs .. maybe that is why she bent a few pushrods. or it just does not like 6500 rpm .
 
stroker402 said:
Thanks guys !
Got the new pushrods in then torqued the rocker arms down to 17 ft lbs. small 5/16 bolt .
when I adjust the valve lash I did it this way which i found on the internet in a few places.

adjust the Intake valve when exhaust valve is starting to open.
adjust the exhaust valve when the intake is starting to close.
everything looks Good to go!

Ice cold engine setting intake at .012 and exhaust at .019
hot specs are as mentioned above .013 and .021 .
I think that should be fine for a cold engine setting .

I think someone might have been there previously setting those valves the wrong way.. they were not in specs .. maybe that is why she bent a few pushrods. or it just does not like 6500 rpm .
Click to expand...

My 273 rattles a bit when cold and quiets down when it warms up. That tells me that the lash closes as the parts expand with heat. I have set mine warm for convenience but set them on the loose side of spec although a thousandth either way shouldn't cause any problems. tmm
 
stroker402 said:
Could someone please tell me what the valve lash specs are on a 1965 273 commando solid cam engine please ?
Also the torque spec on the rocker arm bolts ?
Thanks ! greatly appreciated.
went to go an install a different intake and found two pushrods bent.. did not even notice any difference the way the engine ran. to ticking or rough idle....go figure .
this little engine loves to rev 6500 all day ... maybe too high for it ! That low first gear tach up so fast ........ need a rev limiter i guess.
Thanks !
Click to expand...

Say . what do you guys think why I had those bent pushrods ?? ... I know the people that owned it before me beat the snot out of her AND the valves were not adjusted properly. And I can tell you I never missed a shift since I owned it... I can tell you one thing . this 273 engine loves to rev though... ! I don't know how good this little tach is that is in is but , it just wips over the 6000 rpm instantly especially with that low first gear. Awesome engine !!! and it has a 2.96 gear in the back.
 
My 1st 273 had headers and wound to 7k on a regular basis. I busted 1 pushrod in 3 years and always adjusted my lifters to 13 and 21 hot and running. Messy but accurate. The one I just built doesn't seem to want to rev as high with the stock manifolds.
 
In my opinion if the prev owner hadnt set the valves properly, be thankful you only bent a couple pushrods. Coulda been a lot worse!! In my thread, you will see that dad and I bent 2 push rods and we were turning the engine over with a ratchet. On a side note, when I talked to comp cams about our issues, the tech guy on the phone said that lashes increase with heat...Im like huh??? Metal expands when heated, so wouldnt the lash decrease?? He was adamant that with heat the valve lash increases. Good luck, would love to see/hear how yours runs. Dad and I are very close to firing his up and I want to take a video of it.
 
4spdragtop said:
In my opinion if the prev owner hadnt set the valves properly, be thankful you only bent a couple pushrods. Coulda been a lot worse!! In my thread, you will see that dad and I bent 2 push rods and we were turning the engine over with a ratchet. On a side note, when I talked to comp cams about our issues, the tech guy on the phone said that lashes increase with heat...Im like huh??? Metal expands when heated, so wouldnt the lash decrease?? He was adamant that with heat the valve lash increases. Good luck, would love to see/hear how yours runs. Dad and I are very close to firing his up and I want to take a video of it.
Click to expand...

sounds funny, but the head would expand to some degree i guess?
seems if this was the care wouldn't lash change aluminum head vs cast iron? since they have diferent expansion rates? an aluminum block should change that even more?
 
This is the correction factor if you want to set lash COLD just to start it up and get it "in the ballpark" to break a cam in or whatever. They (Crane) recommend you set it hot after initial start up... so it (lash) SHRINKS when it gets hot, unlike some things ;-)

Iron Block Iron Heads Add .002"
Iron Block Aluminum Heads Subtract .006"
Aluminum Block Aluminum Heads Subtract .012"

That Comp boob was thinking LS1 Chevy AL head iron block, just like his script says....
 
intake20manifold20for20ebay20001.jpg
[/IMG]

Just installed this ld4b intake on the 273 dartcharger today.. went together real Good .
holley double pump 650 going on top. ....just to try .

dougs headers go on in a couple weeks.
 
harvenator said:
My 1st 273 had headers and wound to 7k on a regular basis. I busted 1 pushrod in 3 years and always adjusted my lifters to 13 and 21 hot and running. Messy but accurate. The one I just built doesn't seem to want to rev as high with the stock manifolds.
Click to expand...

I think I will adjust my valve lash again when I get the engine running and hot >>> 13 - 21 for one more check .
my 273 wants to keep reving past 6500 ... that can't be good .. need a rev limiter . for sure ! lol
 
Is it true you can't float out a solid cam engine ?

atleast with a hydralic cam you can feel the engine nose over when your rev it too high.
 
stroker402 said:
Is it true you can't float out a solid cam engine ?

atleast with a hydralic cam you can feel the engine nose over when your rev it too high.
Click to expand...

They don't "float out" so to speak like hydraulics. (the lifters can't stay in contact with the cam as it spins thus keeping the valves open) Solids follow the lobe more efficiently at higher rpm especially with stiffer valve springs. often times the cam will run out of power or the points will float in the distributor at higher rpm. tmm
 
[ame="http://www.youtube.com/watch?v=x4QKHtP63Bs"]1965 Plymouth Barracuda 273 engine on dyno - YouTube[/ame]


Watch this video of a 273 commando on dyno .. woooow !
I'm sure it is worked over alittle lol

go to youtube and read what was done to the engine.. hardly nothing .
youtube >> " 1965 plymouth barracuda 273 engine on dyno "
 
toolmanmike said:
They don't "float out" so to speak like hydraulics. (the lifters can't stay in contact with the cam as it spins thus keeping the valves open) Solids follow the lobe more efficiently at higher rpm especially with stiffer valve springs. often times the cam will run out of power or the points will float in the distributor at higher rpm. tmm
Click to expand...

I wonder why I had two bent pushrod then.. I can see if the valve lash was way out of adjustment ..that could happen then .
but............
being if the lash was so off ..... the pushrods could have way too much slop in them .. jumped out of the rocker arm PR ball socket or lifter socket and got tangled up some and bent the push rod...... just wonder.
 
stroker402 said:
I wonder why I had two bent pushrod then.. I can see if the valve lash was way out of adjustment ..that could happen then .
but............
being if the lash was so off ..... the pushrods could have way too much slop in them .. jumped out of the rocker arm PR ball socket or lifter socket and got tangled up some and bent the push rod...... just wonder.
Click to expand...

Were the pushrods bent so bad that they were out of the balls on the rockers or out of the lifters? I can see how they might bend with coil bind or piston to valve contact. (most common) If the rockers were set way too loose it could cause them to jump out of position and get stuck where they didn't belong. tmm
 
toolmanmike said:
Were the pushrods bent so bad that they were out of the balls on the rockers or out of the lifters? I can see how they might bend with coil bind or piston to valve contact. (most common) If the rockers were set way too loose it could cause them to jump out of position and get stuck where they didn't belong. tmm
Click to expand...

I talked to an older man.... mechanic of 30 years expirience ... asked him how the pushrods could of gotten bent .. says .......only way is if it had a some valves that were sticking ... makes since ...
because ,..... the car sat for 2 years before I bought it .. and when I got it when you went thru the gears and let the motor bring it down down it would Bang thru the exhaust , shoot fire out the muffler new something was not right .
 
everything was in it's ball and socket when I took it apart . pushrods were still moving and attached. but bent .
Engine was running real bad when I first got it from sitting for 2 years . I think it had some stuck valves.. which caused the bent valves.
 
stroker402 said:
everything was in it's ball and socket when I took it apart . pushrods were still moving and attached. but bent .
Engine was running real bad when I first got it from sitting for 2 years . I think it had some stuck valves.. which caused the bent valves.
Click to expand...

Yep! that makes perfectly good sense. Gotta love those old guys! lol tmm
 
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