Still undecided about a cam for my 5.7

[kenh]

What I have and what I want...

1990 C1500, stock 5.7 TBI, shorty direct replacement headers and full flow exhaust, Mildly worked over stock heads.

I've said in the past I plan on building an engine for my 90. My goal is not "high" performance. I'm looking at more of a very fuel efficient engine. Any HP that comes with is just a bonus. I just wish to improve on what is already there. Making some upgrades to a little more modern specs.

One of those changes is upgrading to a roller cam and possibly roller rockers. Not only is more aggressive ramps to get the valves open quicker but the reduction in friction should add a tiny bit of HP. My dilemma is how aggressive should I get? I've thought about simply installing a stock Vortec cam. It has also been suggested that I use a L98 cam. Supposedly great vacuum and good mileage.

Does anybody have any suggestions?

I realize that I will need to upgrade the chip or some other computer work to make the most of what I do. I wish to stay with the TBI and stock manifold for the time being. Trying to be a bit of a tight ass and stay on a slim budget.

Thank you for all your input!

Ken

 

[Frank Enstein]

When I redo Frank's engine I will use the stock Vortec cam. It puts the torque curve right where it can be used. It'll work fine in a TBI setup without freaking out the computer. If you want a little more later you could install 1.6:1 rockers for a little bit more power. You shouldn't even need to get a chip. I would recommend an adjustable regulator and a throttle body spacer as well. JET-61510 regulator and AID-200-540. Those are Summit numbers.

 

[Schurkey]

My '88 K1500 is running a Vortec roller cam and lifters, and 1.6 rockers. The cam and lifters came in the short-block I used; I took the lifters apart one at a time for cleaning, and then re-used 'em.

No problem on stock tune with a few extra degrees of initial advance.

This engine also has aftermarket aluminum heads and a carb intake w/ TBI adapter plate.

 

[Supercharged111]

Marine/Ramjet cam is also a good choice, powerband identical to a stock Vortec cam just more lift, more duration under the curve, but tighter LSA. ICL is 106, I forget what stock Vortec is. I did that with Comp Pro Magnum 1.6:1 roller rockers and the truck had more ass from an idle to redline. I've since added the marine intake and blower. Being a 1990 it isn't unreasonable to expect lifter spider bosses to be cast in your intake valley.

 

[Erik the Awful]

Don't be afraid to call the cam maker of your choice. I highly recommend it.

If you were closer, I'd hand you the cam I pulled from my Vortec. I think I still have it... I tried to sell it for $10 in a garage sale and it didn't sell.

 

[L31MaxExpress]

Stock F/Y- car LT1 cam is a good bit hotter than a Vortec cam and also makes just as much low-end grunt. Factory 96 LT4 cam also works extremely well.

 

[kenh]

Just saw on FB market place fairly close to me a complete less intake Vortec engine for $50. I also have a line on a what I believe to be a vortec style block (from a co worker) that has has the crank ground and has been bores .030 over with new flat top pistons. Was run one night in his race car and he decided to go a different route. No cam, oil pump etc. Just the rotating assembly.

I messaged the vortec guy asking a couple questions about milage and how long it's set. For $50 bucks I can at least get the valve train and possibly the cam and sell the rest and have zero investment!

Ken

PS, Thanks for the suggestions!

 

[kenh]

When I redo Frank's engine I will use the stock Vortec cam. It puts the torque curve right where it can be used. It'll work fine in a TBI setup without freaking out the computer. If you want a little more later you could install 1.6:1 rockers for a little bit more power. You shouldn't even need to get a chip. I would recommend an adjustable regulator and a throttle body spacer as well. JET-61510 regulator and AID-200-540. Those are Summit numbers.

I was/am a little hesitant on using the 1.6 rockers. Sounds like my fears are unfounded. Lots of 1.5 rockers for sale on FB marketplace. Should the spacer be an open design or closed (just two holes)?

Don't be afraid to call the cam maker of your choice. I highly recommend it.

Excellent idea!!

If you were closer, I'd hand you the cam I pulled from my Vortec. I think I still have it... I tried to sell it for $10 in a garage sale and it didn't sell.

HMMMMMMM!! LOL

Ken

 

[Hipster]

Ditto on calling a cam manufacturer. Crower used to have a line of high torque/fuel maximizer camshafts but I'm sure others can grind similar profiles. Bullet, Jones, Crane. Typically you'll get more of what you want out a custom profile then a stocking catalog profile.

I've been into quite a few 88-94 Tbi truck blocks and none have had provisions for a roller set up. I'm not saying there not out there but I haven't seen it so the chances of finding that might be slim.

I tend to stay away from blocks/cores I can't hear run or know for sure they hold water. Used blocks/cores can be a gamble. Blocks crack from freezing and it can be missed on a magnaflux.

 

[PlayingWithTBI]

I've been into quite a few 88-94 Tbi truck blocks and none have had provisions for a roller set up. I'm not saying there not out there but I haven't seen it so the chances of finding that might be slim.

Yeah, it's a crap shoot. If you can find a block out of a Caprice, it may already have a roller cam in it. My Mr Goodwrench long block from ~2000 has drilled and tapped bosses for the spider and drilled, but not tapped holes for the cam thrust plate.

You must be registered for see images attach

You must be registered for see images attach