I'm going to be getting my motor rebuilt but the 2 shops that I am eyeballing don't have any roller blocks. So they will be using older flat tappet style blocks. Now, is this a bad thing? Will I have trouble down the road with this Frankenmotor?

Or should I just wait for a roller block? Time is of the essence, since it's over 110* each day and I am riding a motorcycle to work at peak heat hours.

 

Well, putting and non-roller cam into a non-roller block is just fine. Not as mechanically efficient as a roller, but has served the world well till the rollers were developed.

I believe you can get aftermarket lifters that allow you to use a roller cam in a non-roller block, but I'm unfamilier with every neccesary step or mod needed.(Not really very cheap, either).

By the way, a motocylcle sounds pretty nice on the hot days here. My f-body doesn't have functional A.C.

 

I am doing this. You can use the older non roller style blocks. All you do is install the hydraulic roller camshaft like normal, but you have to run a retro fit hydraulic roller lifter. You see, the hyrdaulic roller lifters are bigger around than a regular tappet lifter. The retrofit lifters I'm using are COMP units, and they cost a whopping $414.99 from jegs. Part number is 249-853-16

 

i would wait till i found a factory roller block. i found one at the junkyard the other day, got all excited till i rolled it over and saw where a rod tried to come through the pan.

 

I was under the impression you had to use a retrofit roller camshaft to go with those lifters, can you just use any roller cam?

 

As far as I know, any regular hydraulic roller camshaft will fit in the block. In my case, I had 2 options because I had a stroker crankshaft. It was either...

1. Use a small base circle cam to clear the connecting rods

OR

2. Use a regular hydraulic roller camshaft but clearance the rods so it fits. This way, I can change out the camshaft and not have to replace it with another special small base circle cam. That way, I will have more of a selection to choose from. This is what I chose to do. Also, the block that I am using is a regular non roller block with a driver's side dipstick.

Either one of those options required the use of those special retro fit lifters. Not to mention that I now have to check for proper pushrod length, and there may be a possibility that I will need custom length pushrods.

 

the original post has nothing to do with using a flat tappet cam in a roller block... its about using a flat tappet block period... this thread is way off topic.
There is nothing wrong with using a flat tappet block... the cams are cheaper.... assoc. parts are cheaper.... they are a little more noisier and you have to break them in...
i personally like roller cams... but you can have a flat tappet machined for a roller retro fit.

 

Well, I didn't mean for it to get off topic. But the way he posted his original post it seemed to me that he wanted a roller block, but was going to settle for a flat tappet block cause his machine shop didn't have one available. And the fact that he mentioned Frankenmotor tells me that he was thinking about trying to mix match some flat tappet vs roller parts to make it work.

 

Paulmore and Nelapse, you are both right. But don't worry. I'm still on the lookout for a roller block. I was thinking of using the stock roller cam in a flat tappet motor, but the way the shop owner was talking it was starting to get expensive for me and a hassle for him.

Just sucks, because most L98's have extremely high mileage and the owners want an arm, leg and first born for it and live out of state.

 

I pulled my roller block from a 93 caprice.... they are out there.. the key to building an awesome engine is
Build what you want, and don't settle for less.

 

I have a related question.

What is the "Real World" advantage to a roller cam? Is it noticeable?

I understand the mechanical principle of a roller cam. I just want to know if it really makes a noticeable difference.

 

No break in... better ramp rates and more efficient

 

Don't overlook 1988 and later GM trucks. AFAIK, even though they may not have been equipped with a roller cam, the blocks are still cast and machined to use the factory roller cam setup, complete with the "dog bones" and thrust plate on the cam nose. You can install an aftermarket factory type roller cam (why would you use a factory grind anyway?) and factory type (less expensive) roller lifters.

 

i would just wait and find a 350 roller block.. if your machine shop cant find one to get in a days time, perhaps you should consider another shop.. there are a TON of them out there, any any good shop knows where to look for cores.

the only exception to this would be if you found a 400 block.. then its worth the extra couple hundred to buy the retrofit roller lifters... that way you have the 400 and a roller cam.

 

I have been told that all Blcks from 1987-1998 had the provision for the roller tapets. On the roller blocs there is a bracket that sits between 2 tappets that do not alow the tappet to turn, on a non-roller engine the tappet is suposed to constantly turn with every stroke of the engine, this alows the wear to be more even, in reality its probably not true.

As far as drivability of the car nothing should change, The down side is the cam will HAVE to be changed, if you find a block with the roller provision then you can use your original cam.

there is nothing special about an L98 Block to my knowledge except there more expensive, probably due to the Corvette. My suggestion would be to find yourself a Vortec engine from a 96 or 97 Pickup, get the Scroggin Dickey intake for TPI, then stuff that in your car. The biggest problem with going that route is you will be limited to the lift of the cam unless you modify the Vortec heads.

It sounds like the mechanics want the L98 engine block as they seem to be more desirable for some unknown reason to me.

On second thought Have them REBUILD YOUR EXISTING MOTOR, why swap it out especially since the car would still have matching numbers. It would be down for a couple of extra days, but if the car is worth something to you thats what I would do unless you want to go to the 350... They might even be able to resleave the engine fo the 350 pistons... its kind of expensive but doable.

I would even suggest to

John

 

actually the tappets DO turn on flat tappet lifters.. its not really flat on the bottom, its curved. and the cam has a angle ground into the lobe.. if the lifters didnt spin, then you would wear them thru in no time....

i woudlnt call that a downside... a cheapie cam kit with lifters for a flat tappet cam is between $75 to $120...
in EITHER case, i would replace the cam, even if its just a daily driver.... just choose something suitable for what you do... in otherwords, no big cams for a daily driver, and no baby cams if you expect strip performance.

theres nothing special about it... but i THOUGHT we were talking shortblocks.. not longblocks with heads...? you're right about the vortec heads being a cheap deal... but if i was doing that, id go once step further and get a diffrent intake altogether.. the longrunner intakes suck.

i wouldnt rebuild a 305, and you cant resleeve it into a 350.