A460 head pushrod question

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A460 head pushrod question

Post  cobrakid8 on May 5th 2018, 4:56 pm

We are still working on getting our FMS A460 headed 521 motor running but today when checking the valves they seem to keep loosening up on us, mainly the Exhaust side. The motor has a 726 lift lunati cam in it solid roller. Has steel crane rockers. Intake side is 9.10 length and the exhaust is 9.80. I have some pictures I will try to post in a little but it seems like the rocker is barely on the spring when fully open. Any help would be appreciated.

Thanks,
Doug

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Re: A460 head pushrod question

Post  Lem Evans on May 5th 2018, 5:00 pm

9.8" is longer that anything I've used on the A460.

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Re: A460 head pushrod question

Post  cobrakid8 on May 5th 2018, 5:10 pm

Thanks Lem, they were way bigger than anything we have in any other engine we have. The block is zero decked and the lifters are crane lifters. rockers are 1.7.

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Re: A460 head pushrod question

Post  Lem Evans on May 5th 2018, 5:19 pm

cobrakid8 wrote:Thanks Lem, they were way bigger than anything we have in any other engine we have. The block is zero decked and the lifters are crane lifters. rockers are 1.7.

BBC rockers?

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Re: A460 head pushrod question

Post  cobrakid8 on May 5th 2018, 8:59 pm









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Re: A460 head pushrod question

Post  norm on May 5th 2018, 10:25 pm

Looks like there isn't much pushrod clearance in the head for the exhaust pushrod too.

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Re: A460 head pushrod question

Post  Lem Evans on May 6th 2018, 11:05 am

What's the deal with the lash caps.....ti valves?

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Re: A460 head pushrod question

Post  cobrakid8 on May 6th 2018, 11:23 am

Lem Evans wrote:What's the deal with the lash caps.....ti valves?

Supposed to be Lem, it as altogether when I traded for the motor and is supposed to have titanium valves and it had the lash caps on them

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Re: A460 head pushrod question

Post  cobrakid8 on May 8th 2018, 2:27 pm

So would these 1.7 rockers work on this motor, or should i put off running it this season until I can afford some 1.73? We are going to get some 9.200 and 9.600 pushrods for the motor as the 9.1 and 9.8 seem to be wrong. This is for FMS A460 heads, with a lunati cam and lifters(gave out crane in error earlier). Was hoping to run it this year to get my oldest some seat time, and next year see about going from alum to steel rods along with a bigger cam, springs and such to get some more power out of it.

Cam is small:
Advertised Duration (Int/Exh): 304/310
Duration @ .050 (Int/Exh): 270/276
Gross Valve Lift (Int/Exh): .722/.722
LSA/ICL: 110/104
Valve Lash (Int/Exh): .022/.022
RPM Range: 4000-7200

Lifters are 72412
Application: Ford V8 370, 429, 460
Diameter: .875"
Weight: 267g
Seat Height: 2.03"

The lifters are comp cam 1.7, but i cannot find any other info on them. Thanks for all the help guys!

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Re: A460 head pushrod question

Post  BigBlockRanger on May 8th 2018, 4:37 pm

Measure for push rods, don't guess at it!
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Re: A460 head pushrod question

Post  BBFTorino on May 9th 2018, 2:30 am

It almost looks like something is in a bind. Are the pushrods contacting the inside of the pushrod hole in the heads??

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Re: A460 head pushrod question

Post  dfree383 on May 9th 2018, 7:11 am

I’d borrow a few 1.73 rockers and see how they measure out

I wouldnt run it like you have it now
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Re: A460 head pushrod question

Post  rmcomprandy on May 9th 2018, 10:32 am

I think they no longer have them available but, Comp Cams used to have some good steel rockers that were 1.7/1 ratio that were for a Ford engine.
Those rocker arm assemblies had the hole in the trunnion slightly offset; (not in the center).
They worked well when the rest of the geometry was right.

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Re: A460 head pushrod question

Post  cobrakid8 on May 9th 2018, 10:41 am

thanks guys, Randy I am not sure if these might be those comp cam rockers you are talking about but they are CC steel and are 1.7 so maybe they were built for a Ford since they are on an old set of FMS A460 heads, but I have no idea and I think i have a bead on some 1.73 and a friend has a pushrod checker we are going to try and get this correct. I just want to get this thing running and out soon before I lose my oldest attention and instead I have a 2000 paperweight sitting in the garage. Hard to keep a 17 year olds attention when they have so many other things going on from girls, playing on their phones 24/7 and I am afraid the longer this goes the less chance he ever races it. Thanks for the help guys and I will also check the clearances for the pushrods to make sure they arent hitting.

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Re: A460 head pushrod question

Post  dfree383 on May 9th 2018, 11:41 am

rmcomprandy wrote:I think they no longer have them available but, Comp Cams used to have some good steel rockers that were 1.7/1 ratio that were for a Ford engine.
Those rocker arm assemblies had the hole in the trunnion slightly offset; (not in the center).
They worked well when the rest of the geometry was right.

Both comp and crower have steel 1.73 stuff available
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Re: A460 head pushrod question

Post  Lem Evans on May 9th 2018, 2:04 pm

dfree383 wrote:
rmcomprandy wrote:I think they no longer have them available but, Comp Cams used to have some good steel rockers that were 1.7/1 ratio that were for a Ford engine.
Those rocker arm assemblies had the hole in the trunnion slightly offset; (not in the center).
They worked well when the rest of the geometry was right.

Both comp and crower have steel 1.73 stuff available

The new Comp XD steel rockers have offset bored trunnons also.

.

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