Question about roller blocks

[Helmantel]

I know that the lifter bores of roller blocks are taller, but do you guys know if the oiling channel was also relocated on the roller blocks?

Some people say that the oil holes are higher on a roller block, but I believe it's in the same place as on regular small blocks, and that the bore is a just a little taller, but I'm not sure.

Thanks,

Arjan

 

[Fox8950]

Nope oil channel is in the same location on both just the taller bores on the roller block like you said. I just went and checked for you even, the distance between the bottom of a flat tappet lifter and the top of the oil channel is the same measurement as from the bottom of the roller tip to the top of the oil channel.

 

[Helmantel]

Nope oil channel is in the same location on both just the taller bores on the roller block like you said. I just went and checked for you even, the distance between the bottom of a flat tappet lifter and the top of the oil channel is the same measurement as from the bottom of the roller tip to the top of the oil channel.

Thanks

Did you make your measurement from the cam's base circle (=bottom of lifter) to the top of the oil hole in the block?

I also noticed that lifter height (bottom to top of ground upper "band"), oil groove width etc. are (almost) identical between flat tappet hydraulic, stock hydraulic roller and the link bar type hydraulic rollers you can get these days.

Therefore, I figured that the only reason that the lifter bores on roller blocks are taller is to raise the lifter guides (dog bones) enough so that they won't get pushed upwards at max lift. That got me thinking about the possibilities of modifying the dog bones so that the U shaped part (which grabs the flat sides of the lifter) sits high enough.

I admit that the valve train may not be a place for such experimentation, but on the other hand, those lifter guides aren't highly loaded moving parts either.

I also discussed it here:

http://www.fordmuscle.com/forums/all-ford-techboard/471578-roller-lifter-dogbone-modification.html

Some claimed that this would lead to oiling issues, but since both the oiling channels in the block and the oiling grooves on the lifters are in the same location, this doesn't seem to be the case.

 

[Fox8950]

Nope I wouldn't see any problem with any kind of oiling issues as long as you could get those dogbones secured well enough. Can't really see what these people saying you would have issues are talking about though maybe they haven't actually LOOKED at the parts. And to answer your question yes thats the measurement I used

 

[Rick 91GT]

The issue in many cases is the oil hole on the lifter actually comes out of the bore, I'll have to measure some of the linked lifters I have at home in the shop....

making sure the oil hole intersects the oil passages properly is very important on the race blocks, I can tell you the holes are not always in the same place on certain lifters...

 

[Helmantel]

I probably need to take of my intake manifold and see if my "theory" works or not. Right now, it's just based on assumptions and guesstimates...

 

[Fox8950]

I don't understand how, if the measurement on the roller and flat tappet lifters is the same from bottom of lifter to top of oil channel, there can be any variation on where they would put they oil galley on ANY block that would use these lifters. If the oil channel on the lifter was going to be pushed up so high it came out of the bore it would happen with both flat tappet and rollers.

 

[Helmantel]

On the flat tappet and roller lifters I compared, the flat tappet had the oil hole near the top of the lifter groove, while the roller lifter had the hole in the ground upper part, but was still fed, through a slot, by the oil groove. So, the roller lifter oil hole sits ~.080" higher and it would come out of the bore a little earlier than the flat tappet lifter. My guess is that this would take a lot of lift, but that's just a guess.

Fox8950, would you care to measure the distance from the cam's base circle to the top of the lifter bore, on both the roller and non roller blocks (which I assume you have available, since you were able to make the earlier measurement?)

Like I said earlier, a mock up will probably tell if it's going to work or not, but I'd rather have somebody else doing the work, so that I don't have to take my fine running engine apart

 

[Helmantel]

Nevermind. I made some measurements and it won't work. Like Rick said, the oiling hole of the lifter will come out of the lifter bore.

A stock lifter bore measures 1.92" from cam base circle to top. The oiling hole on a roller lifts sits at 1.71", so it can only lift 0.21" before it comes out of the whole (=0.346" valve lift with 1.6 rockers)

I should have listened to all the people who said it wouldn't work

Although, in my defense, few came up with the correct reason.

 

[Rick 91GT]

Nevermind. I made some measurements and it won't work. Like Rick said, the oiling hole of the lifter will come out of the lifter bore.

A stock lifter bore measures 1.92" from cam base circle to top. The oiling hole on a roller lifts sits at 1.71", so it can only lift 0.21" before it comes out of the whole (=0.346" valve lift with 1.6 rockers)

I should have listened to all the people who said it wouldn't work

Although, in my defense, few came up with the correct reason.

I give you credit for actually thinking about it, way too many times guys/gals take what they see here on the internet as gospel...



It is popular to have to actually put a vertical groove in the lifters for some models since the main oil passage intersection is not always ideal...