A460 heads with solid flat tappet

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Re: A460 heads with solid flat tappet

Post  tfsbbf466 on December 19th 2013, 6:19 pm

kim wrote:I don't mind whichever cam you decide to run.  Its your engine.  I will say, that if you had enough lifter bounce on the roller to damage the roller finish, I would be VERY leary of flat tappet combination. I have an F150 with 175k miles on a hydraulic roller.  I have an exploder with 150k on a hydraulic roller...  The valves in the A460 head are some large valves, they are going to take a hefty spring to handle 7000k RPM, idling against that spring load is going to make lifter lubrication a concern.
My f150 had 340k with a hyd roller cam before I pulled it to swap to a 351w. But that's a hyd roller with a plunger that can compensate somewhat. I don't think the motor is going to pan out at this time so I'll be sticking with my solid flat tappet 514.

Btw the sft cam I just pulled out probably had 10k miles in 3 different motors and looks perfect. I'd say the current cam has 2-3000 already.

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Re: A460 heads with solid flat tappet

Post  kim on December 19th 2013, 6:34 pm

now if are talking solid roller, then the issue has been a lack of oil in street driven vehicles. There is no provision in the old race stuff to get oil around the rollers. So lots of red light, low RPM, idle time, the needle bearings simply overheated. Modern "street" oriented rollers have provisions to get oil to the needle bearings.

The failure complaints talked about in this thread, is a lack of valve spring. The finish, or hardness coming off the wheel is due to it being used as a hammer. Similar problems now with street app roller cams, beating the needle bearings to death. They were never intended to be used as a hammer, yet they let us get away with some pretty radical lobe cams. In the application of those cams, we may start with enough spring, but those types of spring fatigue fast.

The person that has a hard time with a roller, is going to have an equally hard time with a flat tappet, as they are not going to do the check and replace with due diligence.

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Re: A460 heads with solid flat tappet

Post  Lem Evans on December 19th 2013, 9:16 pm

Using a sold flat tappet lifter ~ like the 817 compcams deal with the EDM hole is a game changer i.m.o.

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Re: A460 heads with solid flat tappet

Post  tfsbbf466 on December 19th 2013, 11:16 pm

Lem Evans wrote:Using a sold flat tappet lifter ~ like the 817 compcams deal with the EDM hole is a game changer i.m.o.
That's what I have in my current motor.

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Re: A460 heads with solid flat tappet

Post  BigRigTech on December 20th 2013, 9:51 am

Lem Evans wrote:Using a sold flat tappet lifter ~ like the 817 compcams deal with the EDM hole is a game changer i.m.o.

I won't bother with anything but the EDM lifters now, the benefit justifies the price difference in my opinion - for what it's worth. Wink 
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Flat tappet

Post  Beast on December 22nd 2013, 2:14 am

I felt the same as you about going with a roller in a street engine. I just got my 547" P-51 headed engine back from the dyno. Apart from not being A-headed it sounds pretty close to what you're looking for. It made 762hp at 6500 rpm and 705 tq with a solid flat tappet from Lem that will work with a 300 hit of nitrous. I went with a set of Howard lifters that has the EDM hole and used Brad Penn oil. No problems with the break in.
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Re: A460 heads with solid flat tappet

Post  tfsbbf466 on December 22nd 2013, 2:34 am

Beast wrote:I felt the same as you about going with a roller in a street engine. I just got my 547" P-51 headed engine back from the dyno. Apart from not being A-headed it sounds pretty close to what you're looking for. It made 762hp at 6500 rpm and 705 tq with a solid flat tappet from Lem that will work with a 300 hit of nitrous. I went with a set of Howard lifters that has the EDM hole and used Brad Penn oil. No problems with the break in.
Very impressive. Should be a stout ride for sure. I don't think the short block is going to come through but I still plan on doing A heads with bigger cubic inch.

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Re: A460 heads with solid flat tappet

Post  quick 52 on December 22nd 2013, 11:10 am

what kind of spring pressure are you running on your SFT... I run a SFT not at your level I've been using 140 seat 360 open... Been thinking of getting a custom cam was there a gain in your swaps

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Re: A460 heads with solid flat tappet

Post  tfsbbf466 on December 22nd 2013, 7:06 pm

I'm running 930 Comp springs looks like 153 seat 383 open at 1.9 installed height. Hard to say what I picked up bc I changed the converter too but I'd say .2 and 2mph on motor and .3 and 3mph on spray with the same jets.

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