Cam degree issue losing my mind!!!!!!!!!!!!

why folks have had rpm/power loss, mostly becauce of the same thing your doing not running the right spring pressure. only shift at 5000-5200 whats that all about. i would shift my grandmothers electra higher than that.

 

a-i think if i were going to shift it higher(6000)or more then yes i may add more spring psi
b-based on valve,retainer,lock.spring mass etc weight,it takes a certain amoutnof spring,and any more is just there for the sake of excessive friction,which in the case of a hyd flat tappet is never a good thing
c-i highly doubt a 455 in motor with limited cross section,exh manifolds,in Denver is making power past where i plan to shift it
d-if you shifted your grandmas electra over 5500 just for the sake of testing the rod bolts,more power to you

 

Nick, the spring pressure lunati says 155-160 is way high but thats what they say there cam needs. there exhaust duration is very fast ramp = to there intake. do you really need that fast ramp exhaust. i ran three or 4 lunati cams never like them. comp has fast ramp for example, they only call for 115-125 seat. theres no reason you cant build a engine to shift at least at 5500. i think you could do a lot better with a different cam. maybe behive springs? your going spend money and your time why not think it out more. you will be alot better off in the long run look at the time you wasted with this cam already.somebody told grandma i was beating on her car and took the keys away before i could blow it up.

---------- Post added at 11:23 PM ---------- Previous post was at 10:56 PM ----------

if you can only shift at 5000- 5200 in denver, why such a big cam ?

 

227-233@050 isnt very big for a 450 in big block
Converter should flash around 3000-3200
With the gear it has and the exh limitations along with the altitude,it should probably peak in the low 5000 range
Will it rev higher?maybe?
Does it matter, or make it run faster-i doubt it
Actually thinking of sending it back and going to a single pattern cam with a touch more at .050 duration

 

Nick

Now your talking. You get this but I'm going to post it anyway.
The higher the altitude the less exhaust volume there is to evacuate from the cylinder so the less exhaust duration is needed.

Something like the TA 310 232/232, .499 lift on a 110 lobe center will work great.
The tight lobe angle will help build good cylinder pressure at that altitude.

If the car never drove to a lower altitude it would be fun to jack up the compression ratio.

Paul

 

least your thinking it over. lunati calls for 3.42 gears and a higher stall converter so it must be a pretty good size. if peak is about 5200 like you say, your shift point should be 300-500 rpm over that. it would seem like you want to be at about 4900, so when you shift you will still be in your power range. i would take all the bottom and mid range power there is to have. its not in stone that you have to advance a cam 4* if its on a smaller size you can put it in straight up or 2* advance to bleed off some comp. Paul, whats the peak on a 232-232 cam its got to be even higer then 5200 rpm.

---------- Post added at 09:11 AM ---------- Previous post was at 08:52 AM ----------

any time you can get away with not running a real high stall converter on the street to make up for a big cam your way better off, less heat more power to the wheels. unless its a switch pitch or lock up converter

 

I get everyones comments
Unfortunately,unless youve ever built a engine for this altitude,it is near impossible to comprehend the effectthe altitude plays on things
When i came out here form LI,NY,i remembered how easy it was to build a low13-hi 12 sec sb car
That same car here,in mid summer,where the d/a hovers at 8000-9000ft, is a mid 14 sec car at best
Hell.i laugh when i see folks comment on a stock stage 1 running mid to hi 13s back east
Thats a nice 15 sec car here
Its funny to go to Mopar day(im a closet Mopar guy lol)or Super Chevy and watch STOCK LS6 cars and 440 Chrysler restored muscle cars running mid to low 15s in street trim
Paul is spot on with his comments regarding cam and exh duration
Too much exh duration ,which would normally help out a weak exh at sea level,will pull all the intake charge out of the cylinder during overlap ,which will kill power even further up here
Cylinder pressure is paramount here,again why Paul stated he'd like to see the compression way up there,single pattern cam ,etc
I could mill the heads further and get close to 11-1 ,but i already have one vehicle that needs race gas,and i dont want two lol
It will be exactly 10-1 compression,so i know our crappy gas will work
Remember folks,the highest octane pump we have here is 91. No Sunoco 93 for us up on the hill
Also our winter fuels are highly ethanol content,so that is also another crow bar in the cog
My old 350 sbb,had a Ultradyne cam,hyd,with 239@050-520 lift on a 108.
The engine only had a true 9.45 -1 compression
Made power to about 6100 or so
I would think this bb would run well to about 5500-5700 with the same cam,and the tight lobe centers would build more bottom end,peaking sooner ,which is ok,as the exh manifolds arent going to want to let it breath upstairs anyhow

Frankly i dont care how fast it goes,as my compulsive racing disorder needs to take a back seat to reliabilty for a
change :TU:
Also ,the car its going in ,will be a F.A.S.T. TYPE build,running street tires,as in 6-7 in wide redlines,so the fun factor of spinning the tiresfrom a stop/slash 20 mph rolling burnouts should be pretty easy and again be a blast on the street
Also ,there is no way,short of massive cubes,to get a car to run decent up here with no converter
The race car now has a 7in unit in it to get it to flash at 6500 up on the brake ,recover at shift,and still be able to lock up on the top end
It sucks makin power up here,but hey,thats the fun i guess of knowing how good of a combo you really have when it runs hard up on the mountain
Stupid cars lol

 

Well,i checked valve to piston clearance today,just a quick check using some clay and with checking springs,and it is not touching the clay on the exh side ,and barely touching the intake
Im going to install a different chain ,then degree it in at 105-106 centerline,and see,what type of clearance i have
,to get the comp back where i wanted it after the chamber work
With the block decking(pistons in the hole .005")and the heads needing milled some more,i dont think i could put much more cam in this thing even if i see fit to.
I need to take about .030" more off the heads still, (to get the comp back where i want it after the chamber work,) which i hope to get most of back when i recheck vtp clearance with real springs.
I should gain .020" or more of that back due to deflection with the checking springs,plus however much it retards the timing while running
Oh well,no sense in overthinking it any longer
Good Day All

 

Nick, You don't get away that easy

What Heads and pistons are you using?

What compression ratio are you shooting for?

Paul

 

Just asking because you didn't mention it,did you use solid lifters when you checked your clearance? Hyd. lifters will give you a false reading.(I'm sure you knew this,but just in case)

If you don't have any solid lifters handy,you can disassemble 2 hyd. lifters and put some kind of spacer in them and put them back together so they're solid for checking your vtp. Then take the spacers out,re-assemble,and brand new used.

 

I wasnt running away
More like a brisk walk lol

Heads are 71 s1 replacemant iron castings, with Stage 1 stainless valves and some porting
Pistons are OEM 1970 dish pistons,i cc'd them at 24 cc's
.040 gasket
Pistons .005 in the hole
Heads should be 69cc when all is finished
Should be right at 9.99 -1 compression

Oh and i used a modified(solid) old lifter to ck ptv
Im not that forgetful just yet
What are you up to Paul lol

 

i didn't read each post but if you are going to use that cam what i would advise doing is checking all of your lobes. in other words check each cylinder with the degree wheel.

 

OK.. so the short block is together and it sounds like the heads will be finished soon so the only variable is the cam. Right?

You have to decide if you want to prove how to make the VooDoo cam work or do something that will work better for Denver hill top.

I know what you said about valve springs but If the Lunati cam is going to work to its full potential it needs the Beehive springs.
At 155 seat pressure the intake will be 342# over the nose and the exhaust 347#.
The hydraulic lifters will not work at that pressure and ramp rate so a set of solid lifters with some way of setting the valve clearance at .010" is needed.

You can proceed with what you have but there will be instability before 5200 rpm with very light springs partially because of valve and lifter bounce.

I went through this similar problem last year. I was way light on the springs and the motor flat refused to go past 7500 under load with 16 pounds of boost.
Last year was a very humbling experience for me. I swear some one beat me up with the stupid stick. I did learn a bunch through all of it.

Paul

 

this is very good advice, same goes for any Schneider or Crower cam. I speak from experience

 

let me see, you want to run a very very fast ramp cam but not use the right valve springs, put in a high stall conveter for your big duration cam that your going to rev to 5000-5200. and the cam itself is not grind right you have to put it in doing this and that and then turn the timing light upside down to time it .o No: it must be all about the combination. at least send the cam back and have them grind a good one if they can.

 

Well 1st off
I believe the cam is ground correctly,as now that it's in on a 108 c/l the @050 open/close numbers are spot on for the installed centerline
Im leaning towards the chain as being the culprit there
Second-i dont quite believe that these 4 cams-with almost 1000rpm swing,20 degrees diff in duration,and .050" lift between smallest to largest,all need the same spring rate?
(If you look at some cam spring recommendations,often times you will see a certain spring be used for a certain family,then the next size cam the spring goes up,then later "up the ladder so to speak",the 1st spring is resused on a larger cam?)
I find it hard to believe that you need that much rate to get a cam to work in that rpm range?
Hell just lookmi the T/A catalog and you can see a vast difference in springs needed from the 212 cam to like a 413 or bigger
And all those are basically the same family of slower lobe designs

a-1000-5200Advertised Duration (Int/Exh): 256/262
Duration @ .050 (Int/Exh): 213/219
Gross Valve Lift (Int/Exh): .470/.484
LSA/ICL: 112/108
b-1300-5500
Advertised Duration (Int/Exh): 262/268
Duration @ .050 (Int/Exh): 219/227
Gross Valve Lift (Int/Exh): .484/.505
LSA/ICL: 112/108
c-1600-5800
Advertised Duration (Int/Exh): 268/276
Duration @ .050 (Int/Exh): 227/233
Gross Valve Lift (Int/Exh): .505/.521
LSA/ICL: 110/106
d-2000-6000
Advertised Duration (Int/Exh): 276/284
Duration @ .050 (Int/Exh): 233/241
Gross Valve Lift (Int/Exh): .521/.544
LSA/ICL: 110/106
As for the converter,ill say it again'
"I live and drive this car in DENVER,at or over 8000ft of DENSITY ALTITUDE IN THE SUMMER"
The car will be a turd without a "looser" converter
Take your car ,you drive at seal level,knock 100 or so hp off(30-35 % total output in bad weather up here to sea level)
And what is left is our hell lol
The supposed 500 ft lbs the 455 made at sea level is now more like 375-400 maybe up here
No converter=no workie workie :grin:
Also ,look at every stock eliminator car at your track,they all have underpowered engines with alot of gear and converter
Thats why they et well and mph poorly
Well thats a good analogy for us up here,poor mph due to lack of hp/air=et's OK by using ^% more gear and converter
All i am saying is before i just go and plop a bunch o' spring on this thing ,i want to make sure my ducks are in a row is all
Ive read of some folks on here running these cams a losing a lobe after a while
And they werent running near the psi's Lunati recommends
Imagine if they were how the cam would wear?

---------- Post added at 08:31 PM ---------- Previous post was at 08:24 PM ----------

Thanks

 

ta-cams are slow ramp 50-60 spread, spring pressure is not that important. my cam has a 44 spread which i thought was fast but yours is super fast at 41 have not seen a faster one. never like lunati cams you even said they told you they cant get good cores. hard to think its the chain. denver is mile high how do you get 8000 ft.between sea level and 5250ft is 9 tenths difference in a 1/4 mile. i would not run a flat tappet cam now with getting it nitride.

 

Look up the desnity alitude for your track
Just because the concrete is built on 5200 ft of elevation,once you factor in temp,humidity,etc,its never the air you race in!

 

dont know you tell me. am at 800 above sea level it was 87* and 68% humidity.

 

it's very common to have a higher density altitude than the actual track elevation due to temperature humidity and barometric pressures.