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Solid roller lifters on a hydro roller cam
http://www.the351cforum.com/viewtopic.php?f=6&t=1298
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Author:  Falcon67 [ Mon Dec 02, 2019 9:33 am ]
Post subject:  Solid roller lifters on a hydro roller cam

Since the search feature of the board appears to be broken - Falcon 351C runs a Howards hydro roller 231175-10 286/294 233/241 @ .050 .594/.611 lift, 110 LSA 106 IC. I'm pretty much limited to around 6400 with their pressure oiling lifters. It'll hit 6500 but the results are inconsistent. I actually have the air shifter set at 6300. I'd prefer to spin this to 6600~6800. I like to swap in a solid but have too many other things to buy for the other car and the always limited budget. If I could get by with switching to solid roller lifters I'd do the cam next year. I know it's done but I forget the potential issues with this half-ass update. Thanks.

Author:  DaveMcLain [ Mon Dec 02, 2019 9:56 am ]
Post subject:  Re: Solid roller lifters on a hydro roller cam

Yes you can do it. Most hydraulic ramps are designed to allow for about .004-.006 of lifter collapse. This means that as long as you set your lash down in the range of .006(hot) at the valve with a 1.73 rocker you will have about the same or a little less contact velocity than what you had with the hydraulic lifter. You'll also end up with about the same seat timing events BUT the cam will grow very very slightly because you'll also be switching from a .700 to a .750 roller wheel. The valvetrain control will be superior and reliability will be better than most solid roller cams simply due to the fact that the lobe is very mild with low pressure angles on the lifters.

Author:  Falcon67 [ Mon Dec 02, 2019 6:29 pm ]
Post subject:  Re: Solid roller lifters on a hydro roller cam

To further clarify, this would be using iron block, iron heads - stock type stuff. TRW flat tops, 64 cc chamber stuffed heads. 10.5:1. So about .008 cold should put it in the .006 hot range more or less. I think the cam timing is decent for the configuration, so just moving to a solid roller would take some guess work out of the shift points. I could then test to find the best one. May also switch it to methanol if I can afford an affordable 250 GPH pump and some replacement lines. Thanks very much for the help!

Author:  DaveMcLain [ Mon Dec 02, 2019 10:10 pm ]
Post subject:  Re: Solid roller lifters on a hydro roller cam

I think that with an iron head that will probably work ok. Set it there and then warm it up to see if it changes all that much. The high RPM stability should be better when using the solids and about the only other thing that you'll have to change besides the valve setting will be the pushrod length.

Author:  Falcon67 [ Tue Dec 03, 2019 9:50 am ]
Post subject:  Re: Solid roller lifters on a hydro roller cam

Thanks. Yes, I'd expect to go over the geometry after changing lifter styles for sure. LOL, those are the cheapest parts of the whole thing.

Author:  DaveMcLain [ Tue Dec 03, 2019 10:07 am ]
Post subject:  Re: Solid roller lifters on a hydro roller cam

The valvetrain geometry will be slightly better with the solids too. You'll be putting the pushrod back in plane with the rest of the valvetrain. Later if you decide to go to a solid roller cam that's more aggressive than your current cam with more lobe lift you'll have to change pushrods again(go longer) but that's no big deal.

Author:  XAFALCON [ Wed Dec 04, 2019 1:06 am ]
Post subject:  Re: Solid roller lifters on a hydro roller cam

Gday Chris,

Just out of interest, what springs/pressures are you running?
Is it a noisey cam?
I have similar cam at moment but lunati, 231/239@0.050 611/611, 110/106.

Cheers,

Rob.

Author:  blykins [ Wed Dec 04, 2019 6:10 am ]
Post subject:  Re: Solid roller lifters on a hydro roller cam

With 53° hydraulic intensity, it's on the aggressive side of the line. More spring pressure could potentially work in your favor if it's giving up early, but you may also then lose control of your lifters.

Author:  Falcon67 [ Wed Dec 04, 2019 9:33 am ]
Post subject:  Re: Solid roller lifters on a hydro roller cam

I'll have to find my notes on the springs, don't remember the specs right off. If I bought the ones listed for that cam in the Howards catalog, I'll need to replace the springs. They call for #98636 - 130 @ 1.875 / 330 @ 1.300, Rate 348, max lift .670, bind 1.150 That reads pretty light to me, more of a solid flat type spring.

Author:  blykins [ Wed Dec 04, 2019 9:56 am ]
Post subject:  Re: Solid roller lifters on a hydro roller cam

Yeah, I'd be at 160-170 seat, 400-425 open.

On my high rpm FE hydraulic rollers that go to 7500, I run 200/500.

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