j par
Well-hung Member
I agree with you just run what you got it's all put together and after running it you'll know what you want.
is it worth the effort? (cam)
- Thread starter 7dart0
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Wyrmrider
Well-Known Member
keep in touch
do try the advance/ retard drill with compression check each time as part of your tuning
keep in touch
do try the advance/ retard drill with compression check each time as part of your tuning
keep in touch
I believe that is a wise decision.
MopaR&D
Nerd Member
Agreed, keep the internals you have and look at other stuff. Maybe try a bigger carb, and what kind of headers and exhaust are you running?
I'm doing a Magnum build with stock pistons and from searching around here you'd be pushing it really close with piston-valve clearance going up to a cam with that much duration and lift. Biggest i've seen mentioned that works with a stock shortblock is around 224-226° at .050" with around .550" lift which is what i'm running (custom grind from Racer Brown).
I'm doing a Magnum build with stock pistons and from searching around here you'd be pushing it really close with piston-valve clearance going up to a cam with that much duration and lift. Biggest i've seen mentioned that works with a stock shortblock is around 224-226° at .050" with around .550" lift which is what i'm running (custom grind from Racer Brown).
7dart0
Well-Known Member
I run a 750 proform carb with mechanical secondaries, TTI step headers, with 2 ½" exhaust with x-pipe exiting in front of rear tires. I think I might look into 1.7 roller rockers. I read a lot of ram and Dakota guys using them. I bought a stud kit a while back to convert my pedestal rockers to stud style which will let me use 1st gen chevy 350 rockers which are cheaper.
txstang84
Well-Known Member
Ken seems like a good dude...I've emailed him a few times about regrinding my magnum roller cam to something with a little more oomph. I wish I had to close proximity you do so I could just go to his business and bs with him about it instead of resorting to email (I out of the States, so can't really call).
mderoy340
Well-Known Member
Post a time slip of a normal pass.
7dart0
Well-Known Member
They are in the glove box of my car. I'll snap a picture when I get out of work.
Tom
Wyrmrider
Well-Known Member
on the roller rockers you must do the mid lift procedure to get the correct length pushrods so the adjusters are with the ball just below the rocker
do not do any rpm with the adjusters screwed way down and too short pushrods
you want a narrow witness stripe on the valve stem when marked with Dykem or a marker
it does not matter much if on center or not- that's not the goal- narrow is but obviously too far to one side of the other means you have the pushrod length wrong or the the rocker arms to long or short
there is a list of rocker arm lengths somewhere
do not do any rpm with the adjusters screwed way down and too short pushrods
you want a narrow witness stripe on the valve stem when marked with Dykem or a marker
it does not matter much if on center or not- that's not the goal- narrow is but obviously too far to one side of the other means you have the pushrod length wrong or the the rocker arms to long or short
there is a list of rocker arm lengths somewhere
7dart0
Well-Known Member
MopaR&D
Nerd Member
You're already in the 12s, how much faster are you trying to go? IMO at this point any really worthwhile upgrades are gonna be big stuff, getting more power out of that setup N/A will take aftermarket pistons with more compression and proper valve reliefs and some port work to those EQ heads, IF you want to step it up to the next level; things like 1.7 rockers or a slightly bigger cam will give you probably 10-20 extra HP and barely any difference in the 1/4.
1.7 rockers with that upgraded cam on fully ported heads. A 1 inch super sucker under the carb, fully port the intake.
mderoy340
Well-Known Member
I would tune what you have first before spending more $$$.
Your 60' is off by 1.5 tenths. You should be able to run a 1.65-1.67
I would start with ignition curve first and then dial in carb second. My 300hp magnum with home ported heads, [email protected] .495 lift ran a best of 11.86. Same gear, tire, etc as your car.
This is what I've found that works on a low 12 high 11 second pump gas SBM in the [email protected] cam range street/strip setup for ignition and 750dp carb.
Ignition: 29*-30* initial @ 1000 rpm in neutral. 4* mechanical advance all in at launch rpm. I launch my car at 2100 and my TA 10" s800 tight converter flashes to 3200 instantly. High initial timing helps off idle transition and throttle response. Vacuum advance is ported and starts to move at 6", max 50* mechanical and vacuum combined. Many will say this is to much timing but it works. You need to be conservative with vacuum advance coming in until you know the fuel curve is good. I use ported vacuum with my 750 proform. I also use ported so it does not affect my launch rpm timing.
Carb: 750 Proform DP, This is the setup I changed from stock. Carb was lean off idle and lean at WOT upper rpm.
Center the main body throttle bore to base plate alignment. Also set transition slot up front and close the secondary as much as possible without touching.
Specs I run and should work for you:
Airgap with center divider upper edge rounded, 1/4" holley open fiber gasket, 1" HVH 4 hole Super Sucker, PCV connected to rear inlet.
IFR .035 moved to bottom
IAB .070
All 4 idle screws 1 turn.
71/85 main jet
MAB .026
Primary PV 9.5, PVCR .059, Rear PV plugged.
4 hole emulsion metering block .028, plug, .028, plug top to bottom.
Pump shot primary Green cam #2 hole .033
Pump shot rear Orange cam #1 hole .031
Suspension:
Mancini Racing SS spring knockoff, Adjustable snubber set 1/4" from floor at the track, 90-10 front, 50-50 rear, 26" 235/60/15 MT ET Street drag radial 20 psi cold. Launch 2100, shift 6200, trap @ 112mph 6300rpm.
Hope this info helps you out. Make one change at a time and if it works keep it, if not go back.
7dart0
Well-Known Member
Wow thanks, I guess I got some work to do. I guess one question I have is what did you do to only limit 4* of mechanical advance?
Tom
Dear goodness...that guy in the other lane broke out by a TON...
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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I have a 230* cam in my combo, and when I first installed it, lost a lot of low-rpm torque compared to the previous 223* cam. But I did gain some top-end power. It took several weeks of tuning to get some of the bottom end up to speed but my final solution was a lower first gear. It took all of the 16% in the swap, to feel like it did before. And as a streeter, and IMO, the top end gain was not worth the power loss. So to this day, I still miss that 223/230/110 Hughes cam. I run 3.55s and a manual trans. The 223 did get me into the 12s with 245/60-14s tho,lol.
mderoy340
Well-Known Member
I run the newer style MP dist that has the Mallory style adjustable advance plate. Each .010 of gap equals around 1*. A .052 drill bit gets you 4-5*.
The other thing I forgot to mention is to make sure the fuel system is capable of delivering enough fuel. You don't want to go lean on the top end at high rpm.
7dart0
Well-Known Member
Do you have apart number for that distributor with the setup inside? I could use a new distributor mines about 25 years old and worn.
mderoy340
Well-Known Member
you may want to contact @halifaxhops he rebuilds and sets up stuff. I don't know if MP still sells this, they dropped support of LA parts years ago. Sorry I don't have a part #.
7dart0
Well-Known Member
I have the FBO limiting plate but Its lowest setting is 10* or locked. No way to get between 0 and 10
All I have are the earlier ones. The newer ones look like a normal distrib but the internals are like a Mallory adjustable. Which one you looking for I might have the part number but no specifications on them. Ma Mopar never published them from what I can tell just motor/point or electronic/ vac or manual advance.
Read it fast 4 degrees at 2200 is easy to do. All in at 50 is doable with a combination of mechanical and vac. Seriously doubt you can get 46 from just a vac advance. If you do let me know how sure it is interesting, never saw one more than 24 at the crank.
I agree, and initial advance is going to be what the combo will take, might have to fill and file the slots on the advance to get the dizzy advance lower. My 340 has 20 initial, any more than that and it kicks back the starter when the engine is up to temp.
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Initial is what you set the timing to before any advance happens in the distrib. My 440 I was breaking mini starter noses off with just a bit of mechanical/vacuum advance kicking in during crank. Turned out it was the vac advance doing it with just a bit of vacuum. Went with a full mechanical Mallory, fixed the issue right away. Now I can run 15 initial with no starter issues.
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