Computer controlled cam

[Frank Enstein]

Hey! What's wrong with 87 - 95?

Not a thing! The newer computers are pickier. And you can't flash a factory 87-95 computer!

 

[PlayingWithTBI]

And you can't flash a factory 87-95 computer!

I can on my 88 with the EBL - as a matter of fact, I have 8 flash banks on it so I can store/run on any of them.

I put a ZIF socket in my 7747 so I can flash SST 27SF512 chips with a Moats Burn 2. You can also install an emulator and flash real time while driving, just saying

Edit: I know you said "factory" computer but, there's plenty of ways to get around that plus, I don't need any dongles or licenses, ha ha.

 

[Frank Enstein]

I can on my 88 with the EBL - as a matter of fact, I have 8 flash banks on it so I can store/run on any of them.

I put a ZIF socket in my 7747 so I can flash SST 27SF512 chips with a Moats Burn 2. You can also install an emulator and flash real time while driving, just saying

Edit: I know you said "factory" computer but, there's plenty of ways to get around that plus, I don't need any dongles or licenses, ha ha.

I have been reading about that just recently and the only thing I currently own with TBI is momma's van with 290000 on it and I ain't pushing my luck! If I broke her van she would strangle me with my own nether bits. She keeps it in her purse ya know...

 

[L31MaxExpress]

I think there is some incomplete info on cams regarding lobe separation.

LSA is only one facet of cam design. It's possible to have a 104 LSA idle glass smooth and a 118 LSA shake the fenders off the truck. The key is overlap when both valves are open at the same time. The higher the overlap the rougher the idle although fast bleed lifters and the tune can mitigate this somewhat. For example, increased timing advance at idle can smooth the idle somewhat.

One affect of a tight (low number) LSA will be a torque curve that favors the middle of the curve but a wide LSA (higher number) will flatten the torque curve for more bottom end and top end at the expense of mid range torque.

All this is dependent on everything else in the engine! Compression ratio, head design, stroker or not, cubic inch, intake and exhaust manifold type, & etc.

Bottom line no one spec on a cam defines it. It is all the specs working in concert with the engine build and the tune that defines how the engine will operate.

And last, some of the people on this forum (or any for that matter) are new to the game and may have a more black and white view because they do not yet understand the complexity of how all this works together. Just know that this forum is a friendly place to learn, teach, & share in the love of our trucks.

Someone that actually gets it! Factory peanut cam in a 305 idles like the rock of gibralter with 22 in/hg vacuum and it is on a 109 LSA. That 178/194 duration lets it have very little overlap.

I went with the rhoads lifters in the 383 to tame the cam for emissions testing reason. Did not want to raise any eyes to the fact it is not a 350 with smog legal headers.

Not sure where he came up with the bit about rhoads lifters not being compatible with knock sensors either. I have run a set in the 305 I had in my 99 Tahoe, another set in a 6.0L and these in the 383. Very little valvetrain noise, in fact the roller rockers on the 383 are the loudest part of the valvetrain.

This is the 383 that is in the van running on a freshly built and recalibrated Q-Jet. First fire up with that Q-Jet. Had run it a few minutes before with a fresh Edelbrock I had just built. I had not even tweaked the idle mix screws yet. Just had them 5 turns out (late model metric fine thread idle screws). A little tweaking had it idling even smoother. 31° of timing advance at idle. Smooth for a 218/228, 0.578 lift cam on a 108 LSA and 106 ICL.

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[Frank Enstein]

Someone that actually gets it! Factory peanut cam in a 305 idles like the rock of gibralter with 22 in/hg vacuum and it is on a 109 LSA. That 178/194 duration lets it have very little overlap.

I went with the rhoads lifters in the 383 to tame the cam for emissions testing reason. Did not want to raise any eyes to the fact it is not a 350 with smog legal headers.

Not sure where he came up with the bit about rhoads lifters not being compatible with knock sensors either. I have run a set in the 305 I had in my 99 Tahoe, another set in a 6.0L and these in the 383. Very little valvetrain noise, in fact the roller rockers on the 383 are the loudest part of the valvetrain.

This is the 383 that is in the van running on a freshly built and recalibrated Q-Jet. First fire up with that Q-Jet. Had run it a few minutes before with a fresh Edelbrock I had just built. I had not even tweaked the idle mix screws yet. Just had them 5 turns out (late model metric fine thread idle screws). A little tweaking had it idling even smoother. 31° of timing advance at idle. Smooth for a 218/228, 0.578 lift cam on a 108 LSA and 106 ICL.

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Not my first barbecue!
I've been learning about cams for over 25 years. But I still defer to Comp Cams when I'm not absolutely sure about a cam choice.

I also use Engine Analyzer and Dyno Sim5 to model the combo before I buy anything.

I degree every cam. The first cam I ever put in was 11 degrees retarded out of the box. I thought I was doing it wrong!
About 18 cams later I had one 10 degrees advanced dot to dot. Every other cam was within .5 degrees of the cam card!

And I've been using Rhoads lifters since 1987. They can really be a help with some combos.

 

[Frank Enstein]

You gotta watch out for the "My Buddy Said" info.

If I ever catch "My Buddy" I'll fix him up with my ex-wife. He'll take his own life saving me the trouble!

 

[L31MaxExpress]

Not my first barbecue!
I've been learning about cams for over 25 years. But I still defer to Comp Cams when I'm not absolutely sure about a cam choice.

I also use Engine Analyzer and Dyno Sim5 to model the combo before I buy anything.

I degree every cam. The first cam I ever put in was 11 degrees retarded out of the box. I thought I was doing it wrong!
About 18 cams later I had one 10 degrees advanced dot to dot. Every other cam was within .5 degrees of the cam card!

And I've been using Rhoads lifters since 1987. They can really be a help with some combos.

I also use engine analyzer and still have a copy of desktop dyno. Both point toward this 383 being in the 490-500 hp range with nearly 500 tq. Very healthy little small block. Even if it only makes 470 its still 80-100 hp more than the old 350 and alot more torque.

 

[Hipster]

I degree every cam. The first cam I ever put in was 11 degrees retarded out of the box. I thought I was doing it wrong!
About 18 cams later I had one 10 degrees advanced dot to dot. Every other cam was within .5 degrees of the cam card!

And I've been using Rhoads lifters since 1987. They can really be a help with some combos.

I've run into that with Herbert Cams. Cam gear indexed way off. It'll make you second guess your methods and re-check multiple times. lol

 

[REM777]

Almost all cam manufactures offer some type of fast bleed lifter these days. They're all over the place. Not as jim-crackery as one would think. Agree on Vortec head flow. Not a whole lot of sense of opening the valve to the point where airflow/velocity falls on it's face or goes turbulent. It's counterproductive to power output and makes for it's own tuning issues yet many guys will go for that big cam or go with 1.6's trying to get to a big lift number.

There are no secrets anymore with fast bleed lifters -why? Rhodes patents have run out. The only mfg making fast bleeds are Howard’s ( Harvey Crane used to make them too ) and I don’t think they still make them because there is a lot of distressed inventory around. Because they you dont know how they are going to work well with knock sensors Because of the machine noise - GM was constantly messing with knock sensor placement and sensor technology. Similar to the LS AFM lifter and oil pressure - IE great idea but the devil in details ( but I digress )

 

[REM777]

My 350 has a 109 LSA and fired up and ran like stock. A black box is no more difficult (98-00) or expensive to tune than a 411. Seriously man, you are way off base here. Plus knock sensors can be tuned and turned off.

Knock sensors will allow you to run an aggressive timing profile for max cyl pressure and save your motor when you hook up the trailer and head for the grapevine -specially you folks who are using hyper explosive pistons like Kieth black