318 Cam Question. Roller Block, Flat Tappet Cam?

[67BELVSLEEPER]

Hi Guys,

I picked up a 87 318 to build for my 67 Belvedere. I took it down to the shortblock and noticed it had a roller cam/roller lifters. I am building this in a budget. Can I use a flat tappet cam on this roller block? I am getting all different answers. Some say no problem, others say I can use a roller cam only.

Any help would be greatly appreciated.

 

[1967coronet440]

If you have the rockers and lifters why not just use a roller cam?

 

[67BELVSLEEPER]

If you have the rockers and lifters why not just use a roller cam?

It seems like the cam selection is more limited and a lot more money. How do the old lifters hold up. They looked ok. I have built a roller based 302 and reused lifters but I had the car for a few years before the build.

 

[Montclaire]

I don't think there are any physical differences about the block that would prevent you from running a flat tappet cam but you lose the advantage of the roller cam and lifters. If you buy another roller cam make sure you get the long snout version so it will operate a mechanical fuel pump. What if you used a stock 360 roller cam? I imagine it has to be more aggressive than the 318 version. I think 360s used a long snout version up until 1989. The diplomat or ramcharger guys could probably tell you more.

 

[Montclaire]

From what I seeing lift on the roller heads is really limited. Also the 360 stick is very mild. So either enjoy a really reliable roller 318 in stock form or sell off the heads and throw in a 340 hp cam.

 

[rumblefish360]

If you have the rockers and lifters why not just use a roller cam?

On the OE engine parts, the rockers are nothing special and the lifters are thankfully cheap unlike a set of after market roller lifters.

I reused the OE roller lifters (360) on a Comp cam with no problems.

The perceive issue is expense. Roller cams are in the $340 area.

 

[rumblefish360]

Hi Guys,

I picked up a 87 318 to build for my 67 Belvedere. I took it down to the shortblock and noticed it had a roller cam/roller lifters. I am building this in a budget. Can I use a flat tappet cam on this roller block? I am getting all different answers. Some say no problem, others say I can use a roller cam only.

Any help would be greatly appreciated.

You can indeed use a Hyd or solid cam in place of the roller but beware that the perceived cheaper route may not be cheaper.

The roller cam will cost approximately $340 from Comp. And then that’s it if you stay with a hyd. roller cam. Worst case extra expense, pushrods.

Now, while a FT cam is, what? Just over a hundred bucks? Now include lifters and pushrods.

Shop around and do the math and realize that the extra pricey roller cam isn’t all that pricey vs a total swap backwards to a inferior cam.

Stroll through Comp Cams and Lunati cams to see what is available. If all you see are low lift cams, your not looking.

 

[rumblefish360]

Comp Cams http://www.compperformancegroupstor...=CTGY&Store_Code=CC&Category_Code=LACAMRFHRXE

Lunati; https://www.lunatipower.com/ProductGroup.aspx?id=289&cid=61

Cranecams new web site sucks balls but they have a line of Hyd. roller cams who’s part numbers end with the letters “IG” which means iron gear for use with the stock intermediate shaft. No bronze shaft to upgrade to. Save lots of money. Check for this feature from other grinders.

 

[67BELVSLEEPER]

I found a few regrind roller cams for about $160. Any thoughts on these specs? I plan on running the stock short block to include pistons.

 

[rumblefish360]

What is the cars Weight?
Trans is a auto right?
Rear gear and tire size

First cam with Hwy gears, stock tires, exhaust manifolds, dual exhaust @2-1/4 w/H pipe.

Second cam with 3.23’s @ a min. 3.55’s would be better. Headers a plus. 2-1/2 w/H pipe.

I’d rather these cams on a 110.

 

[Montclaire]

I have been reading links on this for a day or so now. It seems like you can run a magnum cam and add an eccentric from Hughes for the mechanical pump. Or you can try to find a roller with a long snout from a MP crate engine. The LA roller lifters were SS by the magnum lifters, so no issues there. I have to stop reading threads like these, now I want to do a cam swap.

 

[Montclaire]

[EDIT] The MP 360/300 crate engines used the stock 1989 360 roller cam (and prob very similar CR numbers), which I already have, so the heck with it. You might be able to find a used one cheap, or swap to a flat tappet cam. There was also a member on here who added a magnum top end to a LA roller short block.

https://www.hotrod.com/articles/hrdp-9809-magnum-and-non-magnum-parts-exchange/

 

[YY1]

In case you didn't know, those LA roller engines were advertised at 9.2:1 compression.
(and there's some discussion on whether the early LA '67-'69 are the same parts)

IIRC the magnum was advertised at 8.8. I'd take confirmation or clarification on this please.

By this time those number were a lot more accurate than the 60's and 70's numbers.

 

[67BELVSLEEPER]

Car will be full weight, not sure how much the sedan is. It has a 904 I would like to run 3.55’s. Right now it has 255 60 15’s.

Got the block painted up today. VHT Enamel.

 

[rumblefish360]

I have been reading links on this for a day or so now. It seems like you can run a magnum cam and add an eccentric from Hughes for the mechanical pump.

Correct!

Or you can try to find a roller with a long snout from a MP crate engine. The LA roller lifters were SS by the magnum lifters, so no issues there. I have to stop reading threads like these, now I want to do a cam swap.

No need to source a cam from a create engine. ANY roller cam will do from or for an LA. FWIW, Crane has HR cams that end in IG which stands for iron gear which means there is no need to upgrade to a bronze gear on the intermediate shaft.

I haven’t been in an LA roller engine. I have an LA roller block that I used with a Comp HR roller cam and it all ready had the roller lifters with the dog bones.

 

[67BELVSLEEPER]

I am going to run an electric fuel pump.

 

[dvw]

We've had them reground and reused the factory lifters with no issues.
Doug

 

[Montclaire]

In case you didn't know, those LA roller engines were advertised at 9.2:1 compression.
(and there's some discussion on whether the early LA '67-'69 are the same parts)

IIRC the magnum was advertised at 8.8. I'd take confirmation or clarification on this please.

By this time those number were a lot more accurate than the 60's and 70's numbers.

I'm trying to figure out why the TBI motors were rated as such pigs. The 1974 version of the 360 had 8.4:1 compression and the base 4bbl was rated at 200/290, while the tbi roller 360 had 9.2:1 CR and the same cam as the mopar crate motor but was only rated at 170/260. Is the TBI that restrictive? I think the 5.9 version was rated around 600-650, but who knows how much the programming would allow you to dip into that.

The 308 and 587 heads are both open chamber, correct? It would seem to me that unless the 308s are drastically overrated, a carb and good flowing intake should really wake one of these dogs up.

 

[YY1]

Pretty sure the TBI 360 did not have a crate motor cam.

5.9 Mag was rated 245 net, and was basically the 300 gross rated crate motor.
Those numbers pretty well jive with conversion from gross to net.

 

[Montclaire]

The first gen MP crate motor and the tbi 360 shared the same roller cam. I can't say if that changed over the years but the part numbers on the cams were the same.