#1  
Old 04-29-2019, 06:55 AM
TAQuest TAQuest is offline
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Originally Posted by Stan Weiss View Post
I asked this before and do not believe it was ever answered. What is the cranking compression with the Lunati 703 cam.

While you have owned this car. Has the engine ever run correctly? Looking in at this from the outside I think it time to stop just changing parts and find the problem.

Stan
Yes Stan, it runs perfect right now. Plenty of power. I bet I can get some light under the front tires. It's a really fun ride. But I want the power range lower in the RPM's. This might be perfect for a lot of folks but not for us.
I didn't do a compression check. With 93 and no octane boost it's spark knocking quite a bit. Needs some octane boost as it always has. Not going to be a pump gas engine. It is what it is until I decide to take the heads off. I will work with the high compression until I get sick of buying octane booster.

  #2  
Old 04-29-2019, 07:46 AM
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Originally Posted by TAQuest View Post
But I want the power range lower in the RPM's.
Lower than 1600 RPM.. lol
http://forums.maxperformanceinc.com/...d.php?t=795059

If anything your compression is calling for a larger cam still.
You could drop down to a Voodoo 702, still going to have to tune that carb!

  #3  
Old 04-29-2019, 07:51 AM
TAQuest TAQuest is offline
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Originally Posted by pastry_chef View Post
Lower than 1600 RPM.. lol
http://forums.maxperformanceinc.com/...d.php?t=795059

If anything your compression is calling for a larger cam still.
You could drop down to a Voodoo 702, still going to have to tune that carb!
Dough dude, you don't listen. The carb is tuned.

If you can't find something positive to say then you are not much use here.

What's with the exclamation mark? Too much coffee? lol

  #4  
Old 04-29-2019, 09:18 AM
"QUICK-SILVER" "QUICK-SILVER" is offline
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Originally Posted by TAQuest View Post
Dough dude,
Don't think he read the whole thread or the follow up thread after the engine got put in the car. I'm not going back to read all of both...But seems like there was 10° difference in where to set total timing. That's from where it made peak HP to being able to drive it on the street. Those reverse dyno pull numbers also dont tell us how hard the engine was bucking and jumping like it would on the street with a stick shift.

Engine also went in an automatic car with a 3,000ish rpm stall converter. That makes me think twice about how "useable" that low rpm power really was.

About got sea sick watching the 302 video when he was lugging the engine around. Smoothed up a bunch when he actually drove it like them little engines were made to be drove.

The china HEI I've got here was a gimme. I did not buy it.
Centrifugal advance is slow with strong springs and very limited on how far it does advance. Engine tuned to scream has initial timing way too high for it to run smooth at low RPM's. If you just crack the throttle and vacuum advance comes in....Shouldn't need explaining. Pretty much useless for a stick shift street car with an engine like your's. At least how they come out of the box.

Do believe with some distributor work and fine tuning you could get this thing doing better.
Total cure with the Voodoo cam that builds higher cylinder pressure, in an engine that's already got high static compression. Still gonna feel every cylinder hit at low rpm's.

Got more but need coffee
Clay

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  #5  
Old 04-29-2019, 09:37 AM
TAQuest TAQuest is offline
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Originally Posted by "QUICK-SILVER" View Post
Don't think he read the whole thread or the follow up thread after the engine got put in the car. I'm not going back to read all of both...But seems like there was 10° difference in where to set total timing. That's from where it made peak HP to being able to drive it on the street. Those reverse dyno pull numbers also dont tell us how hard the engine was bucking and jumping like it would on the street with a stick shift.

Engine also went in an automatic car with a 3,000ish rpm stall converter. That makes me think twice about how "useable" that low rpm power really was.

About got sea sick watching the 302 video when he was lugging the engine around. Smoothed up a bunch when he actually drove it like them little engines were made to be drove.

The china HEI I've got here was a gimme. I did not buy it.
Centrifugal advance is slow with strong springs and very limited on how far it does advance. Engine tuned to scream has initial timing way too high for it to run smooth at low RPM's. If you just crack the throttle and vacuum advance comes in....Shouldn't need explaining. Pretty much useless for a stick shift street car with an engine like your's. At least how they come out of the box.

Do believe with some distributor work and fine tuning you could get this thing doing better.
Total cure with the Voodoo cam that builds higher cylinder pressure, in an engine that's already got high static compression. Still gonna feel every cylinder hit at low rpm's.

Got more but need coffee
Clay
Thanks Clay. I'm using a Proform HEI. I'm sure I could spend some time tuning it to lower the power range. If I was stuck with this cam I would have to do that. I'm going to start with a cam that targets the power range I want and then tune that.

When I first came here with my build receipts a lot of folks said 'itty bitty cam'. Or, 'no one with these heads runs a cam that small'.
So I listened and tried a bigger cam. Now I'm going to use a cam that targets the usage of the car. Not what everyone else with these heads uses.
I think the guy who made the build plans in the first place was spot on. He just made a mistake lining up the dots.
So I went and saw what a big cam was all about. Now I'm going to be more practical and follow what the cam selection instructions say when applying them to what you use the car for.
Wouldn't be the first time someone made a mistake and got too big a cam for what they use the car for. I'm just quick to admit my mistake and move forward.

  #6  
Old 04-29-2019, 12:38 PM
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STEELCITYFIREBIRD STEELCITYFIREBIRD is offline
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It's got a TDC reference... FWIW now.

  #7  
Old 04-29-2019, 10:16 AM
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Originally Posted by "QUICK-SILVER" View Post
About got sea sick watching the 302 video when he was lugging the engine around.
I seemed to miss that part, will watch the video again later.
Maybe people are just used to different things.

  #8  
Old 04-29-2019, 10:24 AM
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Formulajones Formulajones is offline
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Originally Posted by "QUICK-SILVER" View Post
About got sea sick watching the 302 video when he was lugging the engine around. Smoothed up a bunch when he actually drove it like them little engines were made to be drove.

Clay
That's not what you are seeing. Trust me. The engine is smooth everywhere. The roads unfortunately are rough around here. I have to drive several miles to civilization plus it's downright impossible to hold the camera still when it's resting on myself, so likely what you are seeing is just me moving around in the seat. It clearly shows these big cam engines are perfectly fine at low rpm if you know how to tune these things. Listening to the engine is what should be paid most attention to, not so much the video.

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