So can you all tell me why everyone bushes lifter bores to restrict oil to the top end on a B1MC headed, T&D paired shafts, KB block engines that will be push rod oiled? I am confused why it is bad to restrict oil thru pushrods vs. lifter bushings. I have spent many hours reading thru old posts here but have not found any solid answers as of yet. I would like to bush my block but need to make up my mind on how to restrict the oil to the top. Ken Black does not think it is necessary but everyone else has different opinions. I would like to think oil to the lifters would be your friend but I have seen a lot of people here restrict it in the bushings. So please help.
Thanks

I added PR oiling to my Hemi and a friends wedge.Lost 15 lbs of OP.Last time the engine was apart,installed restrictors in the push rods and got the 15 lbs back.I put over 2k miles on it every year and get to the track 3 or 4 times.I WANT full pressure to the lifters,even with lots of idleing there is no problem.

I'm assuming your running a solid roller camshaft with the lifters set up for pushrod oiling, correct? If so then are your lifters slotted or solid body? if slotted and have a very small hole in them for the pushrod oiling isn't that a restrictor If solid body with a small oil hole for pushrod oiling how big is that hole? I have a set of Indy 440-1 heads with a set of paired shaft Jesels rocker arms that need pushrod oiling, I'm using a set of Comp Cams # 892 slotted (cut out, not solid body)roller lifters that have two holes in the slots in them for the pushrod oiling those heads. I JB welded up one hole on the non pressure side per instructions from Comp, I'm using them in a stock 400 block that these lifters oiling holes are sitting in the main oil galleys when the lifters are on the heel of the cam so they will oil the rockers for most of the time. I am going to use a set of spray bar covers also to help make sure there is enough oil spraying onto the valve springs(400+ lbs on the seats and 910 to 940 lbs open) to help keep them cool If it ends up flooding the valve covers with to much oil I'll restrict the spray bar fittings to a smaller size. I do have a set of B1-MC heads also that will probally end up with either a set of T&D paired shaft rockers like yours or maybe another set of Jesels Those heads will be used on a Koleno high nickel iron block with the lifters bushed with a small oiling hole already in them from Koleno for a future racing project

I believe the answer is the oil leakage is through the rocker. I have paired T&D. My pushrod are restricted to .040". The rockers and pushrod ends look perfect. I put 300 passes on them and they were used when I got them. My lifter bore clearance is .002", bushed with a .100" feed hole
Doug

Mine is a SB but I have bushed bores with a .060
hole and .040 restrictions in the PRs with TD
paired rockers... it was suggested to me to use
a .040 hole vs .060... I didnt because I have the
EDM hole in the lifters for the axle oiling... the
one thing I didnt know was the EDM hole is .026 and
I was told it was .013.. thats a big difference in
loss

Bushing the lifters is done for a lot of reasons that have nothing to do with restricting the oil to the top end. One reason to bush the lifters is to correct the geometry. Another good reason is to keep the oil gallery from getting exposed during operation or when something bad happens.

If you bush the lifter bores then you have to decide if you're going to run the lifter dry or not. If you want to oil the top end thru the pushrods you have to drill a small hole in the bushing in order to oil the lifter. If you don't drill the holes in the bushings then you have dry lifters and you cannot oil the top end.

Thanks for the info. So bushing the lifter bores is not necessary if you restrict thru push rods? I do know the lifter bores in a KB block are a lot taller that a stock block. I just trying to figure out why you would want to restrict oil to lifters? I'm kinda torn on bushing the block due to cost as for it is another 600$ on top of a 7k block. I just want to do it right the first time as for the KB block is a new thing to me. There is a lot of opinions on this so I am trying to sort thru them. It will be a 4.5 bore 3.9 stroke solid roller motor that will turn some rpm's. I would think the geometry would be perfect in a new block from KB and I do understand the chances of failure and a lifter coming out of the bore and loosing pressure. So it appears the main reason to bush with a small hole in bushing is mainly to protect from loss of oil pressure if a failure happens correct? I do also plan to run a bushed roller lifter rather than a bearing roller lifter if that is worth anything. Thanks

What does KB say? I haven't seen a new KB block so I don't know if the lifter gallery is fed in the same way as a stock block. You might not have an issue if the lifter bores are already divorced from the gallery. I seem to recall that KB used a main gallery elsewhere in the block.

You might have better luck if you start a different thread and ask about bushed lifter bores in a KB block. Someone with recent KB experience can tell you what they know.

I do know that people bush the lifter bores in Indy blocks to correct the geometry but maybe KB has better machining processes than Indy??

440Jim had a KB block set up for pushrod oiling so maybe send him a PM. I think a couple other guys on here also have experience with that. Point is you are asking a very specialized question and your thread title isn't going to help you get the answer.

A standard KB water block does not have any pressurized oil going to the lifter galleries. They offer an option to gun drill the passages to intersect the lifter bores for pushrod and/or lifter pressure oiling. That passage intersects on the opposite side of the lifter bore than a stock block. The KB block does have a different "priority" oiling main passage from the pump to the main bearings. If you order the optional lifter oiling, a passage is machined up the back of the block, around the cam bearing, and then forward to intersect the lifter bores. You can see the main oil passage on the Left side. The holes with the spot face are drilled through the main passage to each main bearing, then a pipe plug is put in each external hole.

I ran my 2014 KB block with the optional lifter oiling passages and T&D paired rockers (pushrod oiling). I restricted the Comp 892 (offset) roller lifters by plugging both ~.1" dia holes and drilling the oil passage side ~0.035". IMO, restricting the pushrod is a valid choice also. My block did not have the lifter bores bushed, as KB does not think it is needed. The cam I ran had lobe lifts of 0.471"/0.451" (int/exh).

Thanks 440Jim. Sounds like you have the same story I was told. The block I have on order does have the lifter oil option. And yes KB told me lifter bushings are not needed. I have just kinda been confused due to so many different opinions and also seeing so many people bushing the lifter bores to restrict oil. I'm sure I have a while till I have to make a decision as for my block has only been on order since Oct. 6 2015...

we run a .030" hole in the bushings and .028" restriction hole in the pushrods.

I modified these to fit the lifter oil galleys of the KB block.

http://www.summitracing.com/int/parts/mor-22016/overview/

Did KB say to run a chrome lifter in that unbushed block instead of a standard steel body roller lifter?

How are you guys restricting the pushrods for limited oiling?

Bushing are not required in a dry bore aluminum block (such as KB or INDY- must be of equivalent alloy). Special material lifters are not required either. I have also used banded and solid body lifters with no notable difference either but prefer banded.

If its not a motor that see's extended idle time such as street cruising. ...dont mess with push rod oiling...not required or desirable for race applications.

ummmmm.....ok, I will continue to do it the wrong way thanks

Says the guy who thinks the world block is superior to Indy/KB.

Don't recall saying it was superior to a KB. I have had them and they are by far the best there is IF you can et one. As for the Indy I will stand by that as I have both. You are right I have no track record and am surely not very well informed

[quote=Al_Alguire. You are right I have no track record and am surely not very well informed [/quote]

What do you mean by that?
I never said or suggested any such thing.

One thing that I will say is that in past, when I have provided input to someone completly other than you, you have more than once made sarcastic-pretentious comments for no logical reason......[ Moparts Family Site - Keep it Friendly ] is wrong with you?

Nothing wrong with me. Maybe just trigger happy over an incorrect statement I suppose

If I offended you I apologize. Lots of ways to skin a cat for sure.