Thats alot of seat timing for a cam that is only 218 @ .050 which I would say is a very slow opening and closing ramps.

Sounds like that cam is really going to kill the dynamic pressure!!

Was this cam degreed in or is this just a guess where its actually installed.

With stock pistons I would say the pistons are about .035 to .045 in the holes plus the gasket thickness you way to much quench.

A leak down test at TDC might be a good place to start as well.

 

I'm taking it to a buddies to see what he has to say about how I did with my timing curve, and he's going to help me do a few tests, plus drive the car. Hell, for all I know, everything is fine, and maybe I'm just used to something with more *****.


Oh, and I do have 2.5 inch true duals, with glass packs. Sorry for forgetting that. And I know that the shorty headers are not a huge step up from stock manifolds, but I run the car pretty low to the ground, and full lengths almost always hang a little lower than the oil pan, which I want to be the absolute lowest thing on the car. Meaning, I was afraid they would bottom out all the time.



Block man, the cam was degreed with a wheel, broken in properly, and then a final tune done to get everything dialed in. I now question whether a did it correctly, which I will find out later today. By seat time, do you mean duration? Give it to me simply, I'm new to this stuff.

 

Kevin,
You are kind of in a tough spot for cam selection to make any kind of HP with 9:1 compression. You can't go too large on duration or you won't make any power because your dynamic compression will decrease. Notice the advertised duration of your Lunati cam, its 284 degrees with only 218 degrees at .050". This is a very, very slow ramp cam, or the term Isky cam up with is "cam intensity". Subtract 284-218=66 degrees. You won't build as much cylinder pressure as you would with a higher intensity cam. The 110 LSA has more overlap which hurts your low end. Like Skunk said it looks like a RV cam.
The other problem you have is the low lift capability with stock Vortecs. You would have more options if you had the heads machined for larger lift cams, this only costs about $100 to machine down the valve guides.

For two cams with much higher intensity I would look at something like a Crane 113521. The specs are 268/280 or 218/230 @ .050 .446"/.459" and its ground on a 112 LSA.

Another very good cam is an Engle 1018H. Heavy street performance cars & vehicles. 9.0:1 compression. Powerband 1500-5500 IN .458” 260°/216° EX .468” 268°/226° 112 LSA.

If you could handle more lift I would suggest an Engle 1020 or a Crane 113521. 1,800-5,800 RPM, 218/230@ .050" 268/280 advertised .459"/.486" on a 112 LSA.

 

Yeah, at the time I was having my heads worked on, I decided for budget reasons not to have more clearance machined in (out?), mostly because I didn't really want to have too much power on a stock bottom end 30 year old 100,000 mile motor anyway.


But if I had known that the result was what it seems to have been...I'd have gone and done that. At this point, I really don't want to spend any more, as this was supposed to be just a top end rebuild to tide me over, fun wise, till I had enough saved up for the new engine/tranny combo.

Hind sights a bitch, ain't it?

 

Just have fun with it Kevin and save some coin for a 383. The 3.08 won't even be an issue then.

 

I'm torn between trying to buy Summit's 383 bare block, and building one (at some point in my life, I want to build a motor from the block up...just because), or buying an LS1 for the weight savings. Used LS1s can be had, WITH T56 tranny, in good cond, for under 5 grand. That's a steal. But I think, if ever want to be hands on with the LS1, I'd have to convert it to carb, and plus, if I want the 383 level power out of it, it's gonna need some work...

My 10 year goal for the car is to have a 5/6 speed tranny, 4 fun short gears, and a decent over drive so I can make the 2 hour trip to limerock race park without it costing me 100 bucks in gas, and wear on the motor. Mate that with 450hp, and the already reduced weight of the car, should make for a fun sunday driving exp. Just a few more years...

 

Some 30 years back, still disappointed after adding a few "go fast" bits to my L-82, including more cam, headers, carb, tuning..., I eventually just gave up on it and BB'ed my '78. Of course, the "crack-o-matic" heads were a big part of that decision, as was my having been somewhat jaded by the BB C3's I had driven by then.


Kevin, it's not for everyone, but I can testify that building a successful mill from the block up is always very fulfilling.

 

So, I had an older buddy look at it, he's my guru who helped me (a LOT) through the top end rebuild, and he says everything looks and sound perfect. He advanced the timing a tiny bit, but told me it was pretty much all set, we took a ride in it, let him drive, and again, he said it feels like pretty close, if not on, 300hp, give or take.

So, thinking I was crazy, I decided to put it to the test...there are no dynos near me, and I don't have the money for that anyway, so I met up with another friend, who has a 96 rustang GT. Went to one of our spots, and let them rip. Before, he would actually walk away from me from about 40mph on, at a pretty steady pace. Now, from about 30mph on, I walk away from him at a pretty steady pace. Up to about 90, at least, anyway. After 90 she gets pretty weak.

I guess it just doesn't feel different, even if it is? Or maybe I'm just not very sensitive...Either way, not sinking another dime into this motor other than oil changes, till I have the cash saved up to do a 383 or LS1. Thanks for all the advice, guys.