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14 apache 01-16-2015 04:46 PM


Originally Posted by GPM (Post 4250887)
The springs I ran on the dyno had 275 at the seat and floated at 5100rpm, the motor was making 1327hp at the time and then started bouncing all over the place.

Ya the boost was not helping that. My engines with 210 on the seat we ran it to 6800 on the dyno and it worked ok with 2.400 valves. It took a long time for the lobes to start to fail 3 sets of lifters later.

14 apache 01-16-2015 04:46 PM


Originally Posted by GPM (Post 4250891)
I ran 260lb at the seat on my BB2xtra 2.3 valve N/A 583, are you talking solid or hydraulic roller ?

Solid roller.
We have run this at 6200 for 20 miles on some poker runs and fun runs.

GPM 01-16-2015 04:48 PM


Originally Posted by 14 apache (Post 4250890)
Yes with a stainless valve you need big pressure. My big dukes have titanium just to help the other parts out.

The titanium should help but it's not the only thing moving in there.

14 apache 01-16-2015 04:53 PM


Originally Posted by GPM (Post 4250895)
The titanium should help but it's not the only thing moving in there.

I am still listening?

Did the 55MM cams and .937 lifters also. You running bushing lifters?

GPM 01-16-2015 04:54 PM


Originally Posted by 14 apache (Post 4250893)
Ya the boost was not helping that. My engines with 210 on the seat we ran it to 6800 on the dyno and it worked ok with 2.400 valves. It took a long time for the lobes to start to fail 3 sets of lifters later.

We had the same problem way back when, all N/A motors wearing out lifters and cams, against the reccomendations of all of the cam techs we upped the spring pressure and our troubles went away.

GPM 01-16-2015 04:59 PM


Originally Posted by 14 apache (Post 4250897)
I am still listening?

Did the 55MM cams and .937 lifters also. You running bushing lifters?

Yes I tried the bushed lifters, only went to the .904s, think about the lifters bouncing over the nose of the cam and part way back up the other side. What size push rods were you running ?
Before this goes to far and maybe it already did because we stole this guys thread. I just wanted to say, I'm not an Engine Builder, I don't sell any parts, I can only relay what I have found from my own experiance, spending lots of money and breaking lots of parts. In the end my boat ran pretty good, what worked for me may not work for you.

14 apache 01-16-2015 05:04 PM

Yes I thing the valve weight for me was to much to get moving. One other thing I did witch I think hurt me was .165 push rod didn't have any flex to soften up opening the valve. I understand that stiff pushrods are a good thing but I don't think it did me any good.
+1.75 rockers

14 apache 01-16-2015 05:06 PM

I should pay to spintron my set up.

GPM 01-16-2015 05:17 PM


Originally Posted by 14 apache (Post 4250901)
Yes I thing the valve weight for me was to much to get moving. One other thing I did witch I think hurt me was .165 push rod didn't have any flex to soften up opening the valve. I understand that stiff pushrods are a good thing but I don't think it did me any good.
+1.75 rockers

I ran the .130 on the N/A motors and the .165 and .200 on the Big Duke, I'm still betting on lack of pressure, who sold them to you? did you check the pressure after tear down ? Good luck with your build !!

14 apache 01-16-2015 05:34 PM


Originally Posted by GPM (Post 4250909)
I ran the .130 on the N/A motors and the .165 and .200 on the Big Duke, I'm still betting on lack of pressure, who sold them to you? did you check the pressure after tear down ?

Bought all the stuff from my buddy's engine shop. All the retainers and shims had no sign of valve float and valve keepers weren't jammed. Still have the old springs in a box here ill check them just to see.


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