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Discussion Starter #1
I have a Dart big M Block Short Deck, 904s, bronze lifter bores, 12 Degree Profiler Heads.

I currently have a set of RL988 Morel lifters with 21 drag race passes. Three of the left offsets are going away. Cylinders 4, 5, and 8. The worst lash went from .024 to .034. I can move the wheel up and down and see the excessive play. All the exhaust roll smooth and the right offsets roll smooth.



The cam lobe has 963 lift 286 duration @.050 opens at 27 BTDC and closes at 79 ABDC. The cam guy wants 420lbs on the seat which I have. Is this too much?

I am not bashing morel. I truly believe its a superior lifter. Spoke to RM in texas and they said they only use 375 on their 1 inch stuff with a captive tie bar lifter. They said they use alot of Crower and Isky.

Can you guys tell me if youve run into anything like this. And what lifters are you using and how much life are you getting out of them.

I wish I could get a hold of morel directly

Thanks for your help
 

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If it is a roller issue, going to the next size larger roller wheel will help a bunch. As the "lift" goes up so does the side thrust on the wheel. A larger wheel changes the load angle.

Blessings..........Ron
 

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Did you restrict the oiling to the lifters at all and what are you using for oil ?Did you ever have any carb or fuel system issues that would have put alot of fuel in the oil ? What is the lifter to bore clearance ? Are there any signs that something in the valvetrain is binding ?
 

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Discussion Starter #6
Im thinking this is not a lifter issue ...
How is your oiling set up?
Hi Chris,
I run a peterson dry sump, I run 3 scavenges in the pan, 1 scavenge on the lifter valley with the natural oil return in the valley welded up with vent stands in the valley to equalize the vacuum from top to bottom. I run the 2 drain backs in the back of the heads teed into the lifter scavenge line.

As crazy as it sounds I drilled a .200 or larger hole in the 2 allen plugs most would use for restrictors. Its my understanding that people are getting away from resticting the lifters in the dart big m. I feed the pressure side over top of the oil filter kinda toward the front.
 

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Discussion Starter #8
If it is a roller issue, going to the next size larger roller wheel will help a bunch. As the "lift" goes up so does the side thrust on the wheel. A larger wheel changes the load angle.

Blessings..........Ron
The wheel measures .805 so Im guessing its a .810 wheel. Im thinking I may need to come down a little on the pressure.
 

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Discussion Starter #9
Did you restrict the oiling to the lifters at all and what are you using for oil ?Did you ever have any carb or fuel system issues that would have put alot of fuel in the oil ? What is the lifter to bore clearance ? Are there any signs that something in the valvetrain is binding ?
I use amsoil Dominator 15/50. I preheat the oil to140/160. The lifters are slightly restricted with the .200 hole. Do you think thats big enough not to cause a problem? I dont have an accurate number for the lifter bore clearance.Il have to measure when I tear down next. But they didnt go in sloppy and werent tight. No binding, went through each valvetrain assembly carefully. I think i only have 2 or 3 pushrods with the exact same length. ya know I did have a float that stuck. I caught it pretty quick though.
 

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Go to a lighter oil like Royal Purple 5w30 or 5w20 XPR oil. I have seen EXCELLENT wear from 0w10 Royal Purple. With the lighter oils, I have seen higher oil temps in the pan and IMO contribute this due to the oil cooling better since we can flow more volume through X clearance
 

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Discussion Starter #11
One thing I forgot to mention(Roller Side Loading)

We sprayed the car for the first time. Very small shot. 22 nitrous 18 Fuel. Ran flawless, plugs looked great, Motor saw 7800 max rpm. Made 2 passes. I wonder if thats what caused it? Even so I know theres combinations out there with moderate power adders with out this problem. My car runs N/A normally. This was just an attempt to go in the 7's
 

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Discussion Starter #12
Go to a lighter oil like Royal Purple 5w30 or 5w20 XPR oil. I have seen EXCELLENT wear from 0w10 Royal Purple. With the lighter oils, I have seen higher oil temps in the pan and IMO contribute this due to the oil cooling better since we can flow more volume through X clearance
How much horsepower have you guys put on royal purple. Thats so funny u said that cause Ive been thinking about trying it. I heard someone say Mike Edwards was using it. Wasnt sure if that was real or just marketing.
 

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I use amsoil Dominator 15/50. I preheat the oil to140/160. The lifters are slightly restricted with the .200 hole. Do you think thats big enough not to cause a problem? I dont have an accurate number for the lifter bore clearance.Il have to measure when I tear down next. But they didnt go in sloppy and werent tight. No binding, went through each valvetrain assembly carefully. I think i only have 2 or 3 pushrods with the exact same length. ya know I did have a float that stuck. I caught it pretty quick though.
To much clearance is not a good thing with roller lifters .0015 to .002 seems to work fine.
 

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Hi Chris,
I run a peterson dry sump, I run 3 scavenges in the pan, 1 scavenge on the lifter valley with the natural oil return in the valley welded up with vent stands in the valley to equalize the vacuum from top to bottom. I run the 2 drain backs in the back of the heads teed into the lifter scavenge line.

As crazy as it sounds I drilled a .200 or larger hole in the 2 allen plugs most would use for restrictors. Its my understanding that people are getting away from resticting the lifters in the dart big m. I feed the pressure side over top of the oil filter kinda toward the front.
If I am reading this correctly,you drilled the 2 allen head plgus in the front of the block that seal the oil gallies going to the lifters.I would think that by doing that you are not allowing all of the oil to go into the galley but rather run down the front of the block and back to the pan and not sending enough oil to the lifters because you have basically created an internal leak.
As far as the thinner oil goes,if you are looking for every little bit out of the combo then go ahead.The only concern with thicker oil is that it does not cold flow and that is where alot of damaged usually occurs,but you are preheating the oil so I don't see that as a problem.I personally would not go to something as thin as a 10weight oil,I usually never go thinner than a 30 weight in Big blocks but that is your decision. What are the bearing clearances and what is the oil temp at during the run ?Amsoil is good stuff,maybe look into something a little thinner from them.
 

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Discussion Starter #15
If I am reading this correctly,you drilled the 2 allen head plgus in the front of the block that seal the oil gallies going to the lifters.I would think that by doing that you are not allowing all of the oil to go into the galley but rather run down the front of the block and back to the pan and not sending enough oil to the lifters because you have basically created an internal leak.
As far as the thinner oil goes,if you are looking for every little bit out of the combo then go ahead.The only concern with thicker oil is that it does not cold flow and that is where alot of damaged usually occurs,but you are preheating the oil so I don't see that as a problem.I personally would not go to something as thin as a 10weight oil,I usually never go thinner than a 30 weight in Big blocks but that is your decision. What are the bearing clearances and what is the oil temp at during the run ?Amsoil is good stuff,maybe look into something a little thinner from them.
In the front of the dartblock theres two 3/8 pipe plugs directly behind the cam gear and a couple inches inboard behind the 3/8 plugs theres there two 1/4 pipe plugs where you would restrict the oil to the lifters.Those are the ones that are drilled with the .200 hole.To have unrestricted oil you would leave out the 1/4 pipe plugs. The oiling system layout is different in the dart block as opposed to the standard big chevy that u would restrict on the bellhousing side above the cam plug. I run the mains in this motor a little loose. The front 4 are set at .004 and the back is at .0045. I run the rods at .004. Im interested in trying the thinner oil though.
 

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In the front of the dartblock theres two 3/8 pipe plugs directly behind the cam gear and a couple inches inboard behind the 3/8 plugs theres there two 1/4 pipe plugs where you would restrict the oil to the lifters.Those are the ones that are drilled with the .200 hole.To have unrestricted oil you would leave out the 1/4 pipe plugs. The oiling system layout is different in the dart block as opposed to the standard big chevy that u would restrict on the bellhousing side above the cam plug. I run the mains in this motor a little loose. The front 4 are set at .004 and the back is at .0045. I run the rods at .004. Im interested in trying the thinner oil though.
With bearing claerances THAT loose, i wouldn't run thinner oil, your fine where your at........ why so loose?????
 

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Discussion Starter #17
With bearing claerances THAT loose, i wouldn't run thinner oil, your fine where your at........ why so loose?????
Let me start by saying I couldnt afford a high end crank at the time. When I bought the block it came with a Howards crank.People told me Howards was processed at callies so I figured it was OK.

I ran this crank for 2 years with a conventional head set up with no problems. When we went to the spreadport heads Im sure we picked up over a 100hp.

When I originally set up the motor. I set the mains at .003 as usual. Upon a routine bearing inspection I saw that the crank was rubbing the bearings on #2 and #4 mains. So I pulled it down thinking the crank is bent or the line bore was slightly off. Sent the crank to be straightend. Crank guy says its straight. Re assemble and off to the track we go again. Put 6 more passes on the engine. notice up by the drainbacks in the heads I have metal. Pull the pan drop the caps same problem. Talk to a good friend who does pro stock engine development. He said that alot of horsepower will cause those cranks to flex so we opened up the line bore main clearance and the problem has gone away. When I was measuring and seeing the numbers I thought it was excessive also but its living. Over the winter Im gonna put a winberg piece in there.

Thanks for the advice on the oil. What oil do you guys run. I run Amzoil and Im cool with that. We ran the old Delo 400 in my brothers Top Sportsman motor. 85 passes and everything looked great, small amount of scuffing on 1 rod bearing on the top, just rubbed the coating.
 
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