Roller cam in non-roller block

[CobraV8]

I sent these questions to the Comp Cams tech support and never got a reply. Maybe one of you guys around here can help.



There's a roller lifter retrofit kit available from Comp Cams that consists basicly of the stock 5.0 lifter guide assembly (Comp Cams #31-1000). However the instructions say this can only be installed when the engine block has the two bosses cast into the lifter valley like the roller blocks do, and you will need a camshaft with reduced base circle in order to keep the lifters from coming to far out of the old blocks shorter lifter bores.

Comp Cams also sells these roller lifters with link bars: http://www.summitracing.com/parts/CCA-8931-16/

As far as I understand these will work with normal base circle roller camshafts in the non-roller engine blocks. Can anyone confirm that?

Simon

[Excaliber]

Hmmm, can't offer a specific opinion on this, but some observations.

The Summit link specifically mentions the 221 and 260 cid blocks IF those blocks originally came with hydraulic lifters. Does that mean the hydraulic lifter blocks had a deeper/longer lifter bore than the soild lifter blocks did?

I don't know about the small blocks but bear in mind the 427 blocks came in two styles. Solids ONLY block as well solid OR hydraulic lifter blocks. That might not have anything to do with the lifter bore depth as it may only relate to lifter bore oiling capability (in both small and big block series).

Comp cams position that the lifter bore depth is to shallow should not be easily dismissed by a Summits claim "it'll work".

[Jerry Clayton]

Simon

I will have my son Corey look into the specific part numbers for answers----However, why not just get a later block that is set up for the rollers???? A big part of our machine work is on these later blocks( both ford and GM) and/or the Dart SHP blocks that have 4.125 bore

Jerry

[CobraV8]

Excaliber, I'm aware of the solid lifter-only 427s, but all small blocks displacing 289 and above do have the oil passages for hydraulic lifters afaik. Also the only blocks with longer lifter bores are 5.0 roller blocks to my knowledge.
You're right it says the lifters can be used with 1960s blocks in the Summit link, however I don't know for sure if a smaller base circle cam has to be used. And I'd rather not find out the hard way

[jdean]

There are two choices you are looking at here:

1) The stock length "5.0" standard type of hydro roller lifters will work in that block but you MUST use a small base circle cam and install the "dog bone" lifter holder kit. This kit requires drilling and tapping the block in the lifter valley. I don't believe there are any block casting restrictions or bosses etc. necessary. Just measure twice and drill once. Don't drill too far or you will drill into your cam bearing. BTW, Comp will make available almost any grind they have in a small base circle, but you may have to special order it. You can special order the small base circle version from Comp through Summit also, which is what I recommend since Summit is easier to deal with than Comp sometimes.

2) If you want to use a normal base circle roller cam, you can, but you need special length lifters like the ones in your link, also sold by Comp and a few others, which makes it a lot more expensive than the first method.

Almost all of the popular crate motor houses use the first method a lot, and it is fairly bullet proof.

Call Mike Forte, Brent Lykins, Keith Craft or any of our engine/parts sponsors and they can help you select parts for this or answer any questions.

[JustOne]

I have a set of these lifters that I may be willing to part with, also cam and push rods for a cpmlete combination with 1600 miles on them. I decided to go with a solid roller setup, but kinda wish the old setup was back in, but don't feel like changing it again.

The Linkbar lifterrs are supposed to be better for high rpm and just drop right into the motor. They worked fine on my 69 block, and although a little more expensive it just seems the easier way to retrofit.

Justin

[PANAVIA]

Ford Racing now has a retrofit lifter kit for rollers now to be placed in non-roller blocks.

M-6500-T58 -- they are brand new.(2010 debut part)

( in my best Steve Martin; The Ford Racing 2010 Catalog is here !!!,
The Ford Racing 2010 Catalog is here !!!, The Ford Racing 2010 Catalog is here !!!)

This is a great part development -as the reduced base circle cams are $$$$.

[bobcowan]

The differance between a roller and a non-roller block is the hight of the lifter boss. That's because the Ford replacement roller lifters are taller than flat tappets.

If you simply drop roller lifters in the non-roller bores, they will stick up so high that they'll starve for oil and die rather quickly. The other issue is that flat tappets are supposed to spin in their bores. But rollers have to be perfectly aligned at all times.

The simplest change is to use a reduced base circle cam, and stock ford lifters and retainers - spider and dog bones. You'll need to to make two small changes to your block. First, you'll need to drill and tap two 1/4" holes in the galley. They only need to be about 1/2" deep. They are directly over the cam bearings, so don't drill too deep. You don't need the bosses cast into the block. You may also need to clearance the galley around some of the lifter bores so the dog bones work correctly. Both of these small jobs can be done with the assembled engine. Just be carefull about chips and shavings.

Here's what it looks like installed in a stock '74 351W block


Here's a close up of the lifters. You can see where I clearanced the block for the dogt bones. It just needed a slight touch with a grinding wheel.



Some people claim the reduced base circle cam is not as good as a standard cam, mostly because the core is thinner. With heavy valve springs, the cam can twist and change the valve timing at the rear of the motor. Unless you're doing a lot of high rpm racing, I don't think that's an issue. But if you were doing that, you wouldn't be using this set up.

The other method is to use a standard cam - with a standard base circe - and link bar lifters designed specifically for this conversion. This is a little easier, but a lot more expensive. The lifters are about $500-600 a set. Also, since they're taller, they heads have to come off to remove them. So if one fails, or you want to swap the cams.......

In my Dart block I use stock modified Ford lifters, dog bones, and spider.

[jdean]

If you install the spider and dog bones, be sure to use red loctite on the bolts that screw into the block. You dont want them coming out.

The Chevy guys have this same situation when upgrading their older blocks to hydraulic rollers, and this is a popular mod for them as well. They've also had good luck with dependability while beating the crap out of it.

[LoBelly]

http://www.compcams.com/community/ar...ID=-1448546337

Comp Cams has copies of articles on its web sites where their products have been used.

In the link above they retro fit a 284HR - RetroFit cam to a 289ci (Using the methods described here - again confirming the knowlege base here )

LoBelly

[Gunner]

Originally Posted by jdean

The stock length "5.0" standard type of hydro roller lifters will work in that block but you MUST use a small base circle cam and install the "dog bone" lifter holder kit.

This is what I have in my 1968 302 block 347. The cam was custom-ground to the builder's specs.

[CobraV8]

Thanks a bunch to everyone, this answered all my questions. I will do some calulations to find out if the stock dog bone and spider assembly with a reduced circle cam or the link bar lifters and a standard cam are more beneficial for me. The engine will not be spun past 6000-6200RPM anyway because it's got a cast crankshaft, so high revs shouldn't be an issue.

Thanks again!

Simon