I have a new accel 74219 "superram cam" sitting in the box ready to go. I was going to put it in my '87 350 roller block, but now that I have all but decided to build a 406 is it going to work?

I called comp cams and the guy there said they're made from different base stock and it won't work at all, but he didn't sound like he knew what he was talking about. Anyway, I've heard that and I've been told that I can use a timing chain for an 87+ roller motor and a thrust button (or something like that) and I'll be fine.

Has anyone done this themselves and can say for sure?

thanks,


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Dan
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87 IROC-Z, 5.7,auto, 3.27, leather, !cat, Holley fpr, K&N'S, SLP 1-3/4" Jet-Hot coated headers, Accel .219 cam, Comp 1.5 roller tip rockers, $uperPITAram, Edelbrock lower intake, Holley 52mm tb, Dynomax\Flowmaster catback. Coming Soon- DFI or prom burner, Dart Iron Eagle 200cc heads, 6" rod 383 or a 406

1987 Camaro Z28 - 5.2tpi, auto, 3.73s, ram air, airfoil, ported plenum, !cat, !tbcoolant, !smog, !4th gear

1989 Pontiac 20th Anniversary Turbo Trans Am - 161,000 miles, !cat, 9" K&N - SOLD

 

I'm running one of Accel's (Lingenfelter's) cams in an older block. Off the top of my head I don't recall the mfr or part number for the timing set though. I'll try to track that info down from my receipts, but it will probably be Monday AM at least before it gets posted.

You will need a set of conversion hydraulic roller lifters since the lifter bosses on the older blocks aren't as tall as the ones on the newer ones. Comp Cams is one supplier; Crane probably has a set also. The different length of the conversion hydraulic roller lifters will require shorter pushrods than for a flat tappet but these are readily available as well.

The thrust button is required to prevent the forward cam walk that can occur with roller cams but not with flat tappet cams (due to differences in the 3D profile of the lobes). I also seem to recall installing some kind of thrust washer to keep the cam from walking backward.

The 87+ roller motors use a thrust plate to control both forward and backward cam travel instead, which requires that a step be cut on the front end of the cam.

Norm


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1979 Malibu w/some cornering tweaks and a few other interesting things

[This message has been edited by Norm Peterson (edited June 08, 2001).]

 

I would really appreciate knowing how you did it. I know about the lifters...I'm just worried about the cam itself. Comp Cams said it wouldn't work b/c the cam "stock" is different, but I'm hoping that just applies to their cams.

Do you remember if you had to do anything else other than use the button? Did you run the stock cover? If you could dig up the part numbers you used that would help alot.

thanks,
Dan

 

The roller cams have a step nose at the front. I am not sure the bolt holes are in the same place, but they probably arent. Also the pin in the front is different (its longer), but thats no big deal. Thats the only differences between the two I know of, besides the lobe shape of course. The journal sizes, spacing, etc. are all the same.

 

So you think i can run a 87+ timing chain and the thrust button and I'll be alright?

thanks,
Dan

 

Hey Norm, Find any information on that thrust plate?

 

IROCZ,

You might have confused the guy at Comp Cams. If he thought you were asking about using a roller cam with flat lifters, I can understand why he cautioned you. A flat tappet cam is made from a more crystalline material (more like cast material) that will be very durable under the constant friction of flat tappets and yet have enough porosity to retain oil to prevent excessive wear. If such a cam were used with roller lifters, the hardened rollers would likely form the metal structure into flakes as they rolled over the surface, and the flakes of metal would end up in your oil pan and pump.

Conversely, a flat tappet used on a roller cam would tend to scuff the surface of the harder roller cam material more quickly, since it isn't designed to retain oil like the flat tappet billets.

You might also need to use a bronze distributor/oil pump drive gear with the harder roller cam billet to prevent wearing your original cast iron gear in short order.

Just a possible explanation...

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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

Haven't forgotten and I'm still looking. I know that stuff is somewhere. (The 1200 mile round trip we took starting Friday after work and ending Sunday @ midnight left me a little tired.)

Related note: some aftermarket hydraulic roller cams are compatible with the original cast iron distributor gear. I think they use a pressed on iron gear instead of just machining the steel HR cam core. Went through that issue too, but the folks at Lingenfelter were much more helpful than irocz's experience with the comp cams line.

Norm

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1979 Malibu w/some cornering tweaks and a few other interesting things

[This message has been edited by Norm Peterson (edited June 13, 2001).]

 

Vader, thanks for the suggestion but I'm positive we spoke about the lifters first (he gave me a p/n to use) then he started talking about how the cam wouldn't work. Of course, he thought I had a comp cam so maybe that is it. I emailed someone from lingenfelter (tried calling long distance and got put on hold twice for more than 10 min. and gave up) & he said that I could use a 87+ chain and a button. I hope he's right.

So anyway I went to the local speed shop and looked at their compcams book. They list two different buttons for a SBC...a nylon that is .795 and a roller button that is .810 (I think those are the lengths anyway). So which do I use? The guy said use the roller one b/c I have a roller cam, but he's an idiot. I'm not saying I don't need to use it, but not just b/c they're both "roller". Does the difference in length make any difference?

Also, if I do run it do I have to buy the comp timing cover w/ the indentation already in it for about $100 or can I take a socket and put my own indentation in my stock cover?

thanks,
Dan