distributor/cam gear
09-09-2007, 05:17 PM
#1
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distributor/cam gear
My 454 mag genIV with 35 hrs started a high rpm miss and suddeny lost about 1000 rpm. Pulled the throttle back and there was the dredded noise coming from the lower end. Oil press was at about 10 lbs at idle.
I pulled the heads this morning and rotated the crank- found vertical play in the #8 piston, but also the distributor gear is worn like razor blades.
When the engine was done last season, we used a new steel gear on the dist, and a cast lunati 420 replacement hyd flat tappet cam. The oil pump was replaced with an HV unit.
Im surmising without having taken the motor apart yet that the bearing failure probably was linked to the dist/cam gear wear.
what gear should be used with this type of cam ? When I replace the cam, should I go with another type than lunati?
I pulled the heads this morning and rotated the crank- found vertical play in the #8 piston, but also the distributor gear is worn like razor blades.
When the engine was done last season, we used a new steel gear on the dist, and a cast lunati 420 replacement hyd flat tappet cam. The oil pump was replaced with an HV unit.
Im surmising without having taken the motor apart yet that the bearing failure probably was linked to the dist/cam gear wear.
what gear should be used with this type of cam ? When I replace the cam, should I go with another type than lunati?
09-09-2007, 10:28 PM
#2
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My 454 mag genIV with 35 hrs started a high rpm miss and suddeny lost about 1000 rpm. Pulled the throttle back and there was the dredded noise coming from the lower end. Oil press was at about 10 lbs at idle.
I pulled the heads this morning and rotated the crank- found vertical play in the #8 piston, but also the distributor gear is worn like razor blades.
When the engine was done last season, we used a new steel gear on the dist, and a cast lunati 420 replacement hyd flat tappet cam. The oil pump was replaced with an HV unit.
Im surmising without having taken the motor apart yet that the bearing failure probably was linked to the dist/cam gear wear.
what gear should be used with this type of cam ? When I replace the cam, should I go with another type than lunati?
I pulled the heads this morning and rotated the crank- found vertical play in the #8 piston, but also the distributor gear is worn like razor blades.
When the engine was done last season, we used a new steel gear on the dist, and a cast lunati 420 replacement hyd flat tappet cam. The oil pump was replaced with an HV unit.
Im surmising without having taken the motor apart yet that the bearing failure probably was linked to the dist/cam gear wear.
what gear should be used with this type of cam ? When I replace the cam, should I go with another type than lunati?
09-10-2007, 10:09 PM
#4
Charter Member # 55
Charter Member
Not usually, but you can run one. Flat tappet cams should not need one. The lobes are angled slightly so the moving lifters actually push the cam toward the back of the block.
Also, Crane makes a 420 replacement cam. I've heard of people talking about a lot of Crane failures, but I've never had one. Also, Crane is what Merc uses.
Last edited by Griff; 09-10-2007 at 10:14 PM.
09-14-2007, 05:29 PM
#5
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Thread Starter
I talked to two cam reps today and they both offered HV pumps as a concern. When looking at the Crane website, in the tech tips area they also write that they do not recommend HV pumps with the flat tappet camshafts.
Anyone have issues with this type of gearwear after HV pump usage?
Will a stock pump deliver enough oil, and significantly reduce strain on the cam/dist gear?
Im just stymied as all components of this motor were new except the pistons and rods which had 8 hrs on them, and checked out fine along with the block and heads.
I really dont want to stick new parts in and have a 35 hr motor again.
Anyone have issues with this type of gearwear after HV pump usage?
Will a stock pump deliver enough oil, and significantly reduce strain on the cam/dist gear?
Im just stymied as all components of this motor were new except the pistons and rods which had 8 hrs on them, and checked out fine along with the block and heads.
I really dont want to stick new parts in and have a 35 hr motor again.
