What is a the difference between a hydraulic cam, and a solid roller cam?

Which type is in my 93 hatchback with the stock motor?

There is a guy i know with a set of Dart aluminum heads for sale. Says they are set up for a solid roller cam. He has a really good price on them and i was just wondering the difference between the two.

Is there any way i can change the heads back over to run with a hydraulic roller cam? How expensive would it be to do this?

Gonna be a street car DD that will see the track a few times a month.

Plan on upgrading the intake and cam too, but just wanna know are these worth grabbing

 

The type that is in your OEM motor is a hydraulic roller. Meaning that oil pressure controls the height of the lifter (meaning pressure raises the height) This is good for a oem application because it keeps the valve lash in check for the most part so you do not need to check it if ever. Hydraulic are usually well suited for most cars that are not all out performance applications and function well under 6500 rpms from my experience.

A solid roller uses a solid lifter that does not adjust from oil pressure. It is a standard height and will not change. The problem with solid rollers are that you (should) check the valve lash ever so often so that it is kept in check. This is only if you have an adjustable valve train if you dont theres really nothing you can do to adjust the lash anyways.
Solid rollers are more of street strip or race motor app. I use one in my 8900rpm 830hp all motor 362ci small block.

Yes you can change the valve train to a hydraulic roller setup, im not sure what you have already or what system is on the heads now but if you could sell the stuff on the dart heads you may be able to cut even on the rockers and springs but would still have to buy the proper length pushrods and lifters if you are not going to reuse your current lifters (id suggest an upgrade). Its going to come down to what you want to do with the car. A solid roller was used in most engines up to the 80s so they can be run fine on the street just wouldnt be as friendly as a hydraulic roller but not necessarily an problem either if your a car guy and willing to maintain everything.

If your going to upgrade the intake and cam already you might as well keep it a solid roller setup and go to a solid roller cam and lifter setup it will be cheaper for you that way. The valve train will be more stable as well. I would go to a solid roller since you plan on going to the track a few times a month.

 

DD hydraulic roller no question! a weekend warrior driven on hte street on weekends only and track use go solid!