scottyp99

Hi, I am planning a sbc build for my 1980 'vette, planning on using a Comp Cams XE flat tappet cam, but I'm thinking of spending the extra money on a retrofit roller cam. Here are my questions:

A cam button is needed, as there is no easy way to install a thrust washer like on the factory roller blocks. Is the stock, stamped sheet metal enough for the cam button to index against? If not, is there an inexpensive solution?

Can anybody point me at a really good tutorial on installing a retrofit roller cam? I want to make sure I am aware of all the details I need to know, I don't like surprises while elbow deep in assembling an engine. I think I have a pretty good grip on the need for bigger valve springs, shorter pushrods (7.3" instead of 7.8") kinda fuzzy on the whole cam button thing, I believe with newer retrofit cams the distributor gear is no longer an issue. Also, is it a good idea to buy a used retrofit roller cam setup, or is it just asking for heartache?


Keep the shiny side up!
Scott

RIO68

Put one in mine--changed the frt cover to one with a extra part (thickness) where the button runs. Brought mine from Doug Herbert cam, lifters, push rods, frt cover and button. Ended up buying two buttons--1st one I cut too much trying to fit the end play. Just take your time and realize you can mess up if you're not careful. I'm sure it is like other things if you did it for a living everyday fitting the button would not be an issue. Like the way my engine runs, glad I changed to a roller.

scottyp99

I'm concerned about a thicker timing chain cover interfering with the water pump, it's a pretty tight fit, right up against the TC cover. Is the extra thickness on the inside? And is it just stamped sheet metal, or is it one of those cast aluminum ones? I have read where guys adjust the cam button clearance by tweaking the stamped sheet metal TC cover with a dead blow hammer, until it just touches the cam button, and using the gasket thickness as the clearance. Sounds a little shady to me, anybody care to comment on that one?


Keep the shiny side up!
Scott

lionelhutz

You ~could~ look for a factory roller block to start with.

Otherwise, I'd want a heavier cover for the button. You don't want any timingchain cover flex letting the can move around. The other option I've seen is a bolt or something like that from the water pump holding against the cover.

Personally, I think a hydraulic roller is a great cam for a street engine. They've produced a great power curve in the hydraulic roller engines I've had.

CA-Legal-Vette

I ended up going with a two piece, aluminum cover with an adjustable cam button that was very easy to set up and maintain. I think it was made by Cloyes but would have to check. It did require some grinding on the back of the water pump, specifically the bolts, to get the pump to seat properly.

63mako

scottyp99

I have been thinking in that direction, also. On the con side, I would have to purchase a core, and the rebuild kits are more money, and I want to stay with the mechanical fuel pump. On the pro side are the one piece rear main seal, which I can live without, and possibly being able to re-use the stock lifters. The expense of the retrofit lifters will probably be offset by the cost of purchasing the core, call that a wash. The expense of the cloyes timing chain cover would be offset by the extra cost of the rebuild kit, so call that a wash. I don't know, it's a pretty close race.

Does anybody have an opinion on whether or not a roller tipped fuel pump pushrod needs to be used? They are kinda pricey, about 110 bucks. Pretty neat, though!!!

edit: How much clearance did you need to grind? Would extra thick water pump gaskets even come close to making up for it? Maybe a thin spacer with a gasket on both sides? Think carb spacer.


Keep the shiny side up!
Scott

Bee Jay

Here is a link to my thread installing an LT4 Hot Cam. I used the Lingenfelter cam button kit.
http://forums.corvetteforum.com/c3-t...onversion.html
Bee Jay

cooper9811

Scotty,

I'm no expert but have done two retrofit roller installs, and I'm sold on them - the first was on a mild 350 with vortec heads. I used a bronze-tipped fuel pushrod from comp, and the cloyes timing cover mentioned above. The cover is easy to adjust for clearance, I believe it has instructions included. Both worked very well. I drove it for about a year before I got bored (was too conservative with the cam, plus I got an itch to build something with significantly more power.

The second build was using the original block which I had previously machined for a stroker engine - I used my bonus to invest in some AFR heads, a longer (but not too long) cam, and this time went with a roller-tipped pushrod and a roller button inserted into the end of the cam - used play-doh to test fit and measure the cam/button/timing cover clearances (I used an older aluminim cover and still have my vortec engine intact in my garage).

Roller (even retrofit) is the way to go - First you have no worries at startup as far as camshaft break in goes - just get the timing right, and fire that puppy up. Worth the peace of mind and even the mild cam in my vortec motor made really good power compared to the stock engine. IN terms of performance, the lobe ramps are often aggressive compared to flat-tappet, so you bet better flow overall with a roller. And you don't have to worry so about whether or not you have enough zddp in your oil.

speedreed8

using howards setup on my 79 350, cam, lifters, springs, pushrods. canton racing products reinforced timing chain cover, no fit issues, roller thrust button, lunati timing chain w/ roller thrust washer machined into gear. using oem fuel pump pushrod, and msd hei streetfire distributor. summit roller rockers on dart iron eagle heads.



http://www.competitionproducts.com/H...o/CL110245-12/

gkull

The Cloyes two piece is a bad product unless you have a mill and a lathe.

quite often the roller buttons need a lathe to machine off some length.

I built a 415 ci motor and it required button machining for a Dart SHP block. My personnal roler motors get the Crane billet timing set and no button of any kind because the chains are so stiff that the cam has near Zero forward play. I proved this by setting a roller button to .005 off the cam. When I tore the motor apart at 15,000 miles the cam had never touched the roller button. I don't use higher volume pumps or excessivly thick oil so I don't load the dizzy gear.

http://www.chevyhiperformance.com/te...lay/index.html

zwede

I retrofitted my big-block. Similar to a SBC retrofit.

The stock timing cover is ok. The cheap chinese chrome covers are not. They're too thin and will flex.

I used the cloyes cover and like it a lot. Had to do minor grinding to clear my aluminum Edelbrock water pump. A factory water pump would probably have been ok without grinding.

The cam clearance depends on the type of cover. With a steel cover you should rock the cam back and forth and measure. I forget the spec, I'm sure you can google it. Something like 0.005" or so.

With the aluminum cover it's much easier. As aluminum expands more you just adjust it to lightly touch on a cold engine. At operating temp that gives you just a little bit of play which is what you want. The cloyes is externally adjustable so it is as simple as turning the adjustment until it just touches the cam.

7t2vette

I have the same experience with the exact same parts on my 406 sbc.

I also have a brand new Comp roller fuel pump pushrod that I will sell you for half price + shipping. I bought 2, used 1 and kept the second for another project that never happened. Let me know.

scottyp99

Hmmmm......a lot of people seem to really like the Cloyes two piece, except gkull. He seems to have experienced a problem that none of you others did. Maybe his experience is a fluke, hope so, anyway.

The grinding for clearance on the water pump seems to be pretty common, how much are we talking about here? 1/8" or less? I could probably account for that with thick gaskets, at least make the grinding left to do that much more minor. Anyway, I don't see it as being anything major, in this hobby, ya get used to having to tweak things, right?

cooper9811--it's all relative, man! You are an expert compared to me! I really appreciate everybody's advice so far, the whole retro roller thing seems to be turning out to be a lot less complicated than I thought it would be.

7t2vette--I like the idea of the roller tipped fuel pump pushrod, I'll think about it, send you a PM if I decide. I'm getting the impression that it isn't necessary, though.


Keep the shiny side up!
Scott

zwede

No, no, the grinding is because the cloys cover is slightly too wide and the edge of the flange contacts the part of the w-pump that goes against the block. I only had to take out a notch, about 1/8" deep. Very minor, just took a minute with a dremel (file will work to).

resdoggie

Is a wear plate required between the cam gear and the block?

scottyp99

Oh!!! I misunderstood, thanks for clearing that up. See, that's the kinda stuff I'm talking about when I say "surprises".


Keep the shiny side up!
Scott

zwede

Some say you should use them, but I switched to a roller cam in the late 90's and haven't had any problems yet.

cooper9811

I think it actually depends on the water pump - I had no issues with where the pump and block meet, but I did have to grind maybe 1/8 inch off the bolts on the back the water pump so it would all fit correctly - and I've heard other say the cover fit with no grinding at all - so like anything, mock it up and check out where you may (or may not) need to grind.

scottyp99

Different people's minds work so differently, huh? My first thought would not be to get the grinder out, but to see if I could get away with an 1/8" thicker water pump gaskets. In my case, that might work out nice, because the serpentine belt is a little close to the front of the water pump pulley, anyway.

Any thoughts on roller tipped fuel pump pushrods? Are they necessary? The fuel pump lobe is really just a concentric circle, it doesn't seem like it would be subject to nearly the same kind of forces that the rest of the cam lobes would.


Keep the shiny side up!
Scott