roller lifters
Posting Guru
Joined: Aug 2000
Posts: 1,127
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From: (near) Denver USA
A roller cam (designed for roller lifters) could give you a lot more power than a flat tappet cam, especially if the rest of the engine is built to take advantage of it.
Roller cams are expensive, and they are not worthwhile in an otherwise stock engine.
Roller cams are expensive, and they are not worthwhile in an otherwise stock engine.
Elder User
Joined: Jun 2003
Posts: 886
Likes: 1
From: Houston/Hope BC
I know nothing about these animals either,
what is "a lot more power" how much and where in the power band?
What other mod's would you think would be appropriate in a roller equiped engine?
Thanks
what is "a lot more power" how much and where in the power band?
What other mod's would you think would be appropriate in a roller equiped engine?
Thanks
Posting Guru
Joined: Aug 2000
Posts: 2,416
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From: PacNW
Roller camshafts have different profiles than flat tappet camshafts. Because of the action of the roller which is on the end of the lifter engine builders are able to take advantage of the much steeper ramp angles that can be achieved with roller lifters to open & close the valve more quickly. Since the valve can be opened & closed faster that also means that it can be left open longer allowing more airflow into & out of the engine.
OK, those are the facts. What follws is my opinion so it could be fiction but given the fact that we know the C (and M) heads flow much better stock than most any other Ford heads, I think that roller cams would work very well on stock heads provided the rest of the valvetrain was built accordingly i.e. a good (3 angle) valve job, roller rockers with consistent ratios and valve springs matched to the cam profile. Of course if you were building an engine like this you would definitely need a better induction & extraction system (4V carb & headers).
OK, those are the facts. What follws is my opinion so it could be fiction but given the fact that we know the C (and M) heads flow much better stock than most any other Ford heads, I think that roller cams would work very well on stock heads provided the rest of the valvetrain was built accordingly i.e. a good (3 angle) valve job, roller rockers with consistent ratios and valve springs matched to the cam profile. Of course if you were building an engine like this you would definitely need a better induction & extraction system (4V carb & headers).
Posting Guru
Joined: Aug 2000
Posts: 1,127
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From: (near) Denver USA
You can get all sorts of lobe profiles on a roller cam, just like on a flat tappet cam, so "how much" power and "where" depends on the lobe profiles you choose. If you go radical, you can go way more radical with a roller cam than you can with a flat tappet cam. And at the upper end, you can get performance from a hydraulic roller cam that is similar to what you would get from a solid flat tappet cam (higher rpm without valve float).
Other than the usual things you should do if you're contemplating serious high performance, roller cams require special roller lifters that retrofit into the block, special pushrods much shorter than stock length because the lifters are taller than stock, high pressure valve springs to control the added inertia of the heavier roller lifters, and rocker arms that can handle 2-4 times the stock valve spring pressure.
Using a roller cam in an engine that was not designed for it (like any 335-series engine) gets expensive. An off-the-shelf cam and lifter kit alone starts at about $600.
Other than the usual things you should do if you're contemplating serious high performance, roller cams require special roller lifters that retrofit into the block, special pushrods much shorter than stock length because the lifters are taller than stock, high pressure valve springs to control the added inertia of the heavier roller lifters, and rocker arms that can handle 2-4 times the stock valve spring pressure.
Using a roller cam in an engine that was not designed for it (like any 335-series engine) gets expensive. An off-the-shelf cam and lifter kit alone starts at about $600.
Senior User
Joined: Oct 2003
Posts: 347
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From: in a house
if your serious about a radical engine build up, go for it. personaly I went with a set of motorsport 1.73 roller rockers I picked up in Carlise PA for 200 bucks. it made a small yet noticable difference. but the engine noise was greatly reduced.
Senior User
Joined: Jun 2003
Posts: 295
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From: Pikeville, KY
Yea That foresure true< I installed a set of roller rockers in my 351m, I could tell real fast, and I couldnt get over how it reduced the noise in the engine.. It was like everything was running on silk.. I couldnt tell really on the power wise.. I id say maybe it freed up 10 horse, It wasnt nothing you could feel.. but it sure made the engine alot smoother..
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