I'm looking at picking up a flat tappet 302 (early 80's?). It's currently a 2bbl (I'll fix that), and he only wants $200. I heard it run, and it runs good.

I was told that it is easy to convert it to a roller.

1. Is that true?

2. Is it worth the trouble/time/cost?

Any help would be greatly appreciated...

 

1. you need a retro-fit kit that has a dogbone, screw-in retainers, and so on.....IIRC they are kinda pricey at ~250.00

2. I dont know from exp if they are worth it. Theres no doubt a roller cam is better (somewhat) than a flat-tappet, but I personally dont think its worth a retrofit kit. I would just start out with a roller block.
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White Girls Webcams

 

Given the option it’s always a good idea to start with a roller block. But there’s nothing wrong with rollerizing the one you have (I Did Mine ).

Yes it is somewhat more expensive to do a conversion (Mostly because you have to purchase the retro fit kit, new roller lifters AND a small base circle cam) but the installation isn’t much more than drilling and tapping a couple holes in the block for the dog bone retainer.

In the end the benefits are the same. You can run a more aggressive cam with less noticeable lope and have reduced friction. The downside to a retrofit, is that you are more limited to your choice of roller cams and can’t just buy something off the shelf for a roller block.

 

Okay, I'm going to ask some noob questions about all this. I understand that a roller cam is beneficial because you can have sharper edges on the profile since you have the roller lifters instead of a flat-faced tappet. I've never researched, or understood why the block has to be modified. Is it so the newer camshafts will sit in the block correctly? Has no cam manufacturer simply put roller profiles onto an old style cam? I assume the roller lifters still sit in the same bores, right?

I brought my pencil....Hey...give me something to write on Man...I don't feel tardy!

 

dang nOObs!

The main issue is that a flat-tappet block's lifter bores are too short for a roller lifter (roller lifter has the "roller" on the bottom that a FT lifter doesn't). So the dogbone has to be there with the Y-shaped retainers to hold the lifters from popping out of the bore.

A roller-cam block is just a regular block with deeper lifter bores, essentially.
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Emilly live

 

If you're hot for any of these teachers then you have MAJOR problems.

 

Are you giving me the eye there? :gay:

 

Lman is correct; Roller lifters are too tall for a non-roller block. But even a roller block has dog bones to hold lifter in place and keep them from spinning in the bores. Small base circle cam’s are required to compensate for the added length of the lifter. Without smaller base circle cam, total lift would be to extreme and you’d be jamming valves through your pistons

 

ahh....... "Queer Eye for the Brown-Vert Guy"
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FlirtyMaid cam

 

No. I'd never move in on Lman's "main squeeze".

 

I converted mine, and it runs like a champ. the cam is a Crane that has 230/238 duration @050 and 575/595 lift. And it is still pretty mild mannered at idle. It is worth it in my opinion.

 

I guess that since I'm getting the motor for 200, and the conversion/cam/hardware is less than 500 that makes it worth it.

Thanks for the info... Any other suggestion/comments would be greatly appreciated. I hope to get this in the car and running by the end of the month...