Roller vs. Flat-Tappet Cams! - Engine Masters Ep. 16 Motor Trend Channel

[Drew Pojedinec]

Why do I feel like I'm trapped in the 60's when I read all this...

Maybe I should ask for a clarification before I post....................

Scott appears to be more of a roller fan.
I'm sure that makes sense, just not in my 63.5, as it is designed to be stuck in the 60's in many ways. 

[blykins]

I'm probably more of a hydraulic roller fan, but I think there's a situation for each type. 

[My427stang]

Paulie, is this in a 427 block without oil to the lifters? or a hyd block?

[plovett]

I have a center oiler block.  So oil to the lifters unless I'm having an aneurism and not thinking right.  It has had a rod out the side and has been welded back together.  It also has a sleeve that has slipped down.  And it's 0.030 over.  I think all those things are okay or can be fixed.  It's going to need custom pistons anyway so I'll go with the absolute minimum overbore, 4.27-4.28"  Somewhere in there.  I'm not averse to a little Hard Blok either, either a couple of inches or a half-fill.

paulie

[wayne]

Well i have learned a lot on this site i think i will sell my roller stuff and buy solid flat tappet set up it will just see street use.

[scott foxwell]

Well i have learned a lot on this site i think i will sell my roller stuff and buy solid flat tappet set up it will just see street use.

That would be unfortunate.

[My427stang]

I have a center oiler block.  So oil to the lifters unless I'm having an aneurism and not thinking right.  It has had a rod out the side and has been welded back together.  It also has a sleeve that has slipped down.  And it's 0.030 over.  I think all those things are okay or can be fixed.  It's going to need custom pistons anyway so I'll go with the absolute minimum overbore, 4.27-4.28"  Somewhere in there.  I'm not averse to a little Hard Blok either, either a couple of inches or a half-fill.

paulie

Not sure if that is a typo and should say "no oil to the lifters"  but a center oiler unless drilled will not have oil to the lifters.

It will be splash (or windage) oiled only, so no pressure fed pins unless the block is modified.

[blykins]

That’s a good point.

If it hasn’t been drilled, options are extremely limited.  EDM lifters won’t do any good, and a non pressure fed solid roller will be short lived.

[plovett]

Thanks guys.  I'm new to 427 blocks and not entirely sure what I'm talking about. I will do some investigating to see what I have.

paulie

[blykins]

Post a pic of the lifter valley or the rear of the block and we can help.

[plovett]

Post a pic of the lifter valley or the rear of the block and we can help.

WILCO and thanks.   I'll try to have pic later today.

paulie

[scott foxwell]

All this talk about lobes and spring pressures and control...and not a single mention of pushrods. Something Jay needs to keep in consideration with a much taller head and one reason I like hyd rollers...if for no other reason, they shorten the pushrods considerably.

[plovett]

Yes sir, pushrods can be a good place to add weight in the valvetrain.  I once had a spring harmonics issue that I THINK was exacerbated by weak flexing pushrods.  I got thicker wall pushrods (and different springs) and all was well. 

paulie

[plovett]

I have a center oiler block.  So oil to the lifters unless I'm having an aneurism and not thinking right.  It has had a rod out the side and has been welded back together.  It also has a sleeve that has slipped down.  And it's 0.030 over.  I think all those things are okay or can be fixed.  It's going to need custom pistons anyway so I'll go with the absolute minimum overbore, 4.27-4.28"  Somewhere in there.  I'm not averse to a little Hard Blok either, either a couple of inches or a half-fill.

paulie

Not sure if that is a typo and should say "no oil to the lifters"  but a center oiler unless drilled will not have oil to the lifters.

It will be splash (or windage) oiled only, so no pressure fed pins unless the block is modified.

No you're right, Ross.  It should say "no oil to the lifters".  I typed "oil to the lifters" on purpose but something in the back of my mind was reeling.  That's why I was wondering if I was having an aneurism.  I think I have a '65 block which would not have pressure fed oiling to the lifters?

I'll look after a while.

paulie

[chilly460]

Good point on the pushrods.  Few years ago I swung through Charlotte and hit some NASCAR shops.  Obviously the new engines they utilize are clean slate engineering, so the cam tunnel is way up in the block to shorten the pushrods.  I was surprised how big they were, though, even being that short.  My thought was they'd run as small a pushrod as possible to knock weight out of the valvetrain but the guide said the tradeoff for stiffness was worth it.  Obvously running 9000rpm for long distance changes the requirements, but the theory stuck in my head.