I'm in the process of building my stroker and was ready to order the cam (or so I thought). The cam selected is a Crane hydraulic roller, 509/528 lift 222/230 @ .050". The cam is $300, but the rest of the stuff of for the install (springs, retainers, etc. is over $700). I bought a new comp .270H last summer for the engine that's currently in the car and bought all new matched components then (springs, retainers, etc.). How muc of it can be re-used with the new roller cam? They all have less than 1,000 miles on them.

 

Hard to say. Obviously you need new roller lifters, but as for springs, retainers and pushrods, you need to find out what is required, and if yours meet those requirements.

First of all, you need to know what valvespring is required for your new roller cam. Your cam company can tell you what spring pressures and installed height is needed. Valvesprings are not somwhere you should cut corners or save money. A valvespring which is inadequately sized or of inadequate pressure can lead to catasprophic engine failure, and that's no exaggeration. Knowing what the spring pressure and installed height requirements are, you need to measure your springs pressure. If you don't have the necessary tool, a machine shop can meaasure them for you. If they don't meet the pressure requirements, then you need to replace them. As for the installed height requirement, this works along with the spring pressure requirement. You can install a spring at a lower installed height (as long as the coil doesn't bind and you have adewquate coil clearance and retainer to seal/guide clearance) and the pressure will increase compared to installing it taller. You adjust spring installed height either by shimming the spring, using retainers that are machined with higher or lower spring steps, longer valves etc. Most of the time on relatively stock setups, you just need to adjust the shims between the head and the spring to achieve the required installed height and spring pressures. More than likely your retainers are not offset, if they are, they will typically be stamped, i.e. .050 or something.

More than likely you'll need to change pushrods since most roller lifters are taller than tappet lifters. Crane can give you an idea, but it never hurts to measure for correct pushrod length with an adjustable pushrod. You can buy an adjustable pushrod set for $30.

New springs are cheap insurance, especially considering your stepping up from a tappet to a roller cam. Obviously the rolller cam has more intense lobes, and probably more lift, so it's inlikely your current springs will be sufficient anyway.

 

You might as well take a leap of faith and go to the solid roller. Then you would be able to use your push rods. Maybe.

One of the big reasons that I skipped hydra roller was the rpm limit. One missed shift or tranny failure at or near red line with WOT and the whole motor can blow up before you can get it shut down.

 

I agree with Monty. I installed a roller cam set up in my 68 BB. I needed an entirely new valvetrain. Obviously the lifters are different as is the cam. The pushrods are definitely different length and I doubt your old flat tappet springs will suffice for a roller cam and you must go to full roller rockers (at least that is what my engine builder told me). Also, don't forget you need a special fuel pump pushrod for a roller cam if you are running a mechanical fuel pump.

 

I'm running a hyd roller with roller tip rocker arms and stock valve covers. My conversion was $600 (cam, lifters, pushrods, cam button and lock plate).

 

Why go with a roller cam?
Unless you are going for super high lift and/or racing, I don't see the need.
For a street car, you are adding 24 more items that can potentionally fail.
For a max effort/budget race engine however, soild roller :smash:

 

The main advantage is that you can use a profile with less duration and more lift than that required of a flat tappet to make the same amount of HP & TQ. This is mostly due to the design of the roller cam lobes & lifters which open (& close) the valves more gradually (linearly) thus keeping them open longer.

Bottom line is that a comparable HP/TQ roller engine is a much more streetable than a flat tappet one.

Mark

 

Does it justify the cost?
I can see why Monty & gkull would run a roller cam -
but a 350 will still be a 350 at the end of the day.
(or a 383)
For the money you would spend on that roller setup, your about half way to one of the aftermarket blocks. Drop that new stroker kit you are planning into a Motown or Dart block and use that as a solid foundation.

;)





[Modified by 71coupe, 5:16 PM 11/6/2001]

 

Cost justification is an individual call. What you or I might feel is not justified may be justified to someone else. In this case, the roller cam based on HP/TQ benefit vs cost, is probably not. The $1000 for a 20-30 HP gain is expensive ($35-50 per HP). The best cost/benefit cam for the street is probably a solid flat tappet.

On the flip side, we all know the best HP/TQ benefit vs cost item is N2O ($2-4 per HP) but many people won't touch it because of the (mis)percieved danger of engine damage. :D

Mark


[Modified by mdsmith, 4:59 PM 11/6/2001]

 

A mild motor with a H-roller might be a wonderful device. Everybody has some goal in mind when building. IMO The biggest gains are in the heads.

I just ran my parts in the Jegs catalog:

$300 cam
$300 Steel roller rockers
$330 Crane solid roller lifters
$120 +.200 over pushrods
$80 ARP 7/16 studs
$330 1.55 springs for .700 lift and titanium retainers
$160 Crane stud girdle
$110 Crane steel billet gear and chain
$110 Cloyes two piece roller button for roller cams timing cover

Ruffly $ 1800, so lesser quality parts $1200 is still my estimate that I would quote people.


[Modified by gkull, 4:03 PM 11/6/2001]


[Modified by gkull, 4:49 PM 11/6/2001]

 

Ok, I know what you guys are saying. What I'm getting at is why gold-plate a production block 350? I've been there. It starts out like this and before you know it, you're married into your motor because you've got too much into it. :crazy: :eek: :sad:


[Modified by 71coupe, 2:19 PM 11/6/2001]

 

using the same profiles you should get a reasonable gain in HP due to less friction.
then on top of that you can use a better profile and have the engine just as smooth.

if you going to consider the cost , you should also consider the roller will last
you a lot longer as the roller has less wear.

Chris :cheers:

 

I tend to agree that the cost isn't worth the return on a street engine. Of course, I don't do any hotrodding, and simply love my comp hyd. lifter cam. For the kind of money it takes to convert to roller cam I would much rather purchase some better flowing heads, or save that cash to put toward a zz4, which has the heads and a roller setup. Of course, this really wasn't a discussion on whether or not the cost was worth the return anyway was it? Oh well, still a fun topic.

 

I already had all the cost vs. benefit discussions before deciding to go hyd. roller. I'm building a stock appearing motor (LT1 clone) that will be raced occassionally, but mostly street driven. Ii purchased a 383 short block from my brother (his car caught fire) that had a couple thousand miles on it. He was roughly 400 hp, but had crappy heads and a waay huge cam that would have required a lot more gear than I wanted to put in the car, so.....cam swap time. My bro-in law talked me into the hyd. roller for performance reasons. I can get more out of a hyd. roller motor and retain more streetability. Obviously, for straight bang for the buck, the cheapest route would be to squirt it.
At any rate, it looks like I'll need to buy the whole deal (springs, pushrods, blah, blah blah $1100 + rockers, studs, valves and gaskets).

 

if you have got the cash somebody has something to sell you... in my opinion i would go with a hyd. cam but as apposed to getting a 274 get a 282 or what ever it is you want.

I would try to find the flattest torque curve in a cam thats possible from the lowest rpm to the highest. Just so that it launches like a rocket and keeps going and going.

ZD :seeya

 

Dalannex - I got a little side tracked on the cost issue. I was in in same situation as Randy (upgrading my motor) I finally stepped up to the plate and bought a pair of Dart aluminum heads after hearing good things about them. Although there are other things I should have bought, this seemed like the best bang for the buck.
I've read about reliability issues about roller cams with the cost factor & decided it wasn't for me. Do the late factory roller motors have any problems with their cams?