Lunati cam too much for a 318?

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VF69HARDTOP

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Hi guys

Im slowly piecing together the parts for the engine while Im working on the body to send it off to the painters.

Im after some advise on the following two Lunati Voodoo cams, 10200703 and 30200740. I know the later is step up but it only requires near the same supporting upgrades and around the same stall speed and I don't want to run a larger stall than 2500rpm. Seeing as I need to fit the correct 73949 valve springs for either cam, I need to upgrade the rockers so Im looking at getting Hughes roller rockers.

Due to needing to run roller rockers, a few people are suggesting I just run a solid flat tappet cam while Im at it. So, my question is, will the 30200740 solid be too large for the following 318 engine spec or should I stay with the 10200703? I want to make some grunt with it but also want it to be streetable and not carry on like a stuck pig.

318 + 0.30" oversize KB 167
10:1 comp
Alloy heads with 2.02/1.60 valves (Aeroflow, Aussie brand with Eddies specs)
RPM air gap inlet
Good headers
Pertronix Ignitor III billet dizzy with matching coil
Carb/FITECH not decided but leaning towards the EFI
2500rpm stall max in a 904
I have either 3.45 or 3.9 gears sitting here, happy to use either

The car is not a daily driver and won't be covering long highway stretches. More used for a cruise around town with a trip to the qtr mile every now and then. Its going in our Aussie version of your 69 Dodge Dart.

Thanks in advance for any feedback.
 
Either cam should work, but the 30200740 will have higher dynamic compression due to the shorter duration and should use the 3.91 gear because of the power range of the increased duration at .050 and it's lift. It would be more for strip use.

I'd probably pick the 10200703 with either gear for your application.
 
Why only 2500 max stall speed? IMO , even the 10200703 is a little on the large size for a 318 with just a 2500 converter.
 
I run a Lunati 10200704 in the 340 in my Duster. Great cam. The 10200703 is a step down from that, but it's a great cam as well. I actually have one in the 318 I'm building, although I haven't run that one yet to know anything about it. My 340 build looks like this...

'68 340 block, .060" over
KB 243 pistons, .018" over the deck
9.8:1 compression
308 iron heads, 2.02/1.60 valves and stage II ported and flowing 264cfm at .500"
Eddy RPM AirGap intake
Doug's headers
Holley Ultra 750 DP, mechanical secondaries
Mallory Unilite distributor, 20* advanced at idle, 35* all in mechanical

Currently running 3.55's out back, although 3.73's would probably be better. I've got a 4 speed though.

I think the 10200703 would be fine for your build, the 2500 rpm stall should work ok as Lunati actually recommends a 2400 rpm stall with the 10200703.

Here's a clip of the 10200704 at idle. Pulls about 9-10" of vacuum idling at 750-800 rpm or so.


[ame]https://youtu.be/62bjHlxzsoA[/ame]
 
Well, you could do what I did; build the engine the way you think you want it to be.Then just keep throwing stuff at it until something sticks. It get's a bit expensive, and the parts pile up on the shelf, but in the end, you get a dynomite package.
Start with the 2500 and 3.91s, and skinny street tires;it will be fine.
 
AJ/FormS said:
Well, you could do what I did; build the engine the way you think you want it to be.Then just keep throwing stuff at it until something sticks. It get's a bit expensive, and the parts pile up on the shelf, but in the end, you get a dynomite package.
Start with the 2500 and 3.91s, and skinny street tires;it will be fine.
Click to expand...

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^This is terrible advice. J.Rob
 
I know! It's a wake up call, designed for shock value.

My first cam(292/108 ) made a lot of power. From 5000 to 7000 plus; not the greatest for street driving.
My second cam 223@050/110,made a huge bunch of torque, awesome for bombing around, showing off and for cruising endlessly while getting 32 mpgUS on oxyginated fuel(all it's ever run).
My third and present cam at just a wee bit larger 230@050/110, can't touch the 32mpgs, and can't touch the big cam top-end, but it is an awesome street/strip combo, with emphasis on street. More torque than 295s can handle, and pulls strong to 7000. Idles all day at 700, pulls right off idle, will run in parades without overheating, etc,etc.
Along the way, I tried to make each of these combos work in the chassis, swapping chunks and trannys, and playing the ratio game endlessly.In the end I went to a GearVendors.
And I now have a shed full of spare stuff, broken stuff, and still untried stuff.Probably worth as much as the final combo(not including the GV).
The lesson I learned is for a streeter Hp numbers are far and away the least important numbers, cuz the power requirement just is not there. Limited to just 60 or 70 mph,and mostly under 45 mph, 300hp is plenty. But 400 ftlbs, from just off idle to 3500/4000 is awesome.And that can be done with torque multiplication.
Putting 300# into a 3.09low, and 3.55 rear puts about 3300ftlbs into the rear axles.(my Combo)This is a pretty big number for a streeter.With an auto and 3.91s, this would require 343# at the crank of your teener.Easily do-able. At 2500 IDK? It'll be close.Chose your cam wisely..the 703 might do it.
But moving up a gear to second in my combo,results in 400 x 1.92 x 3.55 =about 2700 ftlbs, which, in a teener would require 2700/(1.45 x 3.91) =480ftlbs, and you are done.
But when I get to third,400 x 1.40x3.55 = about 2000 ftlbs. your teener, still in 2nd will be putting out in the neighborhood of 343 x 1.45x 3.91 = just about the same 2000 ftlbs to the rear axle.At 3200 in 2nd, with 26 inch tires you will be travelling at about 44 mph, and right in the thick of torque.

So don't do what I did, unless your pockets are deep and you really enjoy the adventure. Stay conservative on the cam, put the flow into the heads instead.And never lose sight of the intended useage! Don't try to make a racecar out of a streeter! especially with a small engine.Build for torque, and gear it to keep it on the pipe and thus increase the average hp over time.If you are stuck with a 3 gear, well,In a streeter it's not the end of the world;

"Start with the 2500 and 3.91s, and skinny street tires;it will be fine."
 
Please don't fall into the 2500 rpm stall converter trap.

Buy a GOOD converter that flashes higher 3500 and is still tight on cruise. The car will react/accelerate much better than a shelf 2500 unit that likely won't stall 2500 at all... BTDT! And a good converter won't slip on cruise as much as some of the shelf stuff either.

The cam is getting on the aggressive side for a 318. It will want plenty of initial timing. Should run real strong.
 
The OP's question of "is the cam too large?" has much more to do with the use of the engine and car than with the parts listed. With the limit on the stall of 2500 RPM, I would say that the OP is tending to emphasize the street/cruising performance more than all out drag strip performance. If that is the case, then I'd go smaller on the cam, even dropping down 1 or 2 steps on the hydraulic cam. But I am not really sure what the emphasis will be, with intended uses as stated; I can see the OP going either way with this build and his description of use.

OP, please let us know what use of the engine is the most important for you. When you say "cruising around town" do you mean a lot of low RPM smooth running, or hard launches at traffic lights to make a lot of noise and tire smoke? My cam choice would vary with that answer.
 
Hi guys,

Thanks to all for the input. The car will be used for cruising with the occasional blast and a trip to the qtr mile. The reason on the 2500 rpm stall was to keep it street friendly and not flaring constantly on normal take off from the traffic lights but if you can get a tighter stall that will flash higher, id be happy with that.

I guess Im a little confused on the specs between cams and how they operate as when comparing the 10200703 and the 30200740, the 703 is bigger in adv duration than the 740 but then its smaller than the 740 in .050" duration, the 740 has a heap more lift but then they both need a 2400-2500rpm stall. So would this mean they would both drive pretty similar? I would like something warm but not to the point that it will be a pig to drive tamely when wanted and was worried it could do this being only a 318 compared to bigger cubes.

I can't help but think if Im spending the same amount of money for either set up I could go the solid 740 and the car will drive very similar but offer that bit more power when needed, or am I getting this totally wrong?

I went through this a couple years ago with a Nissan 180SX SR20DET that I kept upgrading cams and turbos until it hit a genuine 400wrhp and then thought to myself, why didn't I do this set up in the first place and same some wasted money.

Sorry if Im coming across like a blonde chick buying a new skirt but I haven't had a heap of experience with building a V8, it seems a lot more work to get a nice combo.

Thanks again for the help guys, I appreciate your experience and input. It just shows how great this community is!
 
You're seeing the difference between solid and hydraulic lifter flat tappet cam profiles in the relative advertised and .050" duration differences. I like higher lift versus duration, but I have not yet found any solid cam around that I personally would use for street cruising; the .050" durations all start too large for my preferences. Other my be happy with something like the 740....so there is a lot of personal subjectivity in these decisions.

Your described use for the car makes sense with the stall RPM limit that you cited. My concern is that you will be dissappointed in the cruising department with either cam and will be below the bottom end of the engine's torque almost all the time while cruising around. My opinion on the cam maker's advertised RPM ranges is that they tend to stretch the lower RPM's to make them look more street/cruise friendly, but they don't run that way. The only cam maker whose RPM range descriptions I trust is Crane. So, while the Lunati says 2500 RPM, I am thinking 3200 RPM minimum 'happy' RPM range. The Crane text description of cruise RPM for a solid flat tappet cam with similar .050" duration says "3400-3800 cruise RPM, 10.0 to 11.5 compression ratio advised".

So, if you do go with something the 740, pay attention to their notes on minimum 10:1 static CR; they are not fooling. Also note that they recommend some steeper rear gears; that again is an indication that this cam is not ideal for low RPM torque and mild cruising. With less CR and gears, the engine will be a dog on the bottom end. You might make up for it with a higher stall speed, but then you will again be compromising low end cruising. You can't tweak the compressor or impeller blades to make up for it like in a turbo set up!

Don't think I am being harsh, but IMHO it seems like the cardinal sin of going too big on the cam for a street car is being committed here. Your story on the Nissan seems to say that you want the large RWHP for some purpose.....???? That tends to fight with easy street cruising operation, where broad torque reaching down low is important. I like the rest of your combo, but the cam choices, I question. At least they are easy to change out.

Yes, it may indeed be a lot more work than the Nissan; the advantage of the turbo shines through here. It is one more variable to tweak to optimize an engine; you just don't have that variable to play with in a normally aspirated V8. I have worked with Mitsu 2.6L turbo's for rallying, and have worked through a progression of turbos too FWIW; there is a lot that can be varied in a turbo without even touching the cam.
 
VF69HARDTOP said:
Hi guys,

Thanks to all for the input. The car will be used for cruising with the occasional blast and a trip to the qtr mile. The reason on the 2500 rpm stall was to keep it street friendly and not flaring constantly on normal take off from the traffic lights but if you can get a tighter stall that will flash higher, id be happy with that.
Click to expand...

Still plenty of 1970-80's thinking out there when it comes to converters. People that say or think that new high stall/flash converters act like stepping on a marshmellow haven't driven anything will a good converter.
 
A good converter is pricey and its a crapshoot to hit it right.The solid is about the same size as the hyd. when you figure in lash ,either way your ok.With the solid you can vary lash with the hyd. you can always use rhodes lifters both will be a little noisy if you dont mind that.Besides adv. duration is only 264-272 on the solid
 
VF69HARDTOP said:
Hi guys,

Thanks to all for the input. The car will be used for cruising with the occasional blast and a trip to the qtr mile. The reason on the 2500 rpm stall was to keep it street friendly and not flaring constantly on normal take off from the traffic lights but if you can get a tighter stall that will flash higher, id be happy with that.
Click to expand...

My 3800 stall converter is very street friendly..
 
So to keep it more street friendly and maximise HP, am I then better off using something with a smaller duration but higher lift? This will keep the power band in the lower revs but maximise HP within that range, say 1500-6000rpm as an example.

If this is the case, should I be looking for something like this instead? How does the LSA affect a camshaft, is a smaller number better for street, say a 106 or is a 110 better?

http://www.hughesengines.com/Index/...&level2=RmxhdCBUYXBwZXQsIFNvbGlk&partid=30395

http://www.summitracing.com/int/parts/hrs-710461-10

http://www.summitracing.com/int/parts/hrs-710581-10

Thanks
 
VF69HARDTOP said:
Hi guys

Im slowly piecing together the parts for the engine while Im working on the body to send it off to the painters.

Im after some advise on the following two Lunati Voodoo cams, 10200703 and 30200740. I know the later is step up but it only requires near the same supporting upgrades and around the same stall speed and I don't want to run a larger stall than 2500rpm. Seeing as I need to fit the correct 73949 valve springs for either cam, I need to upgrade the rockers so Im looking at getting Hughes roller rockers.

Due to needing to run roller rockers, a few people are suggesting I just run a solid flat tappet cam while Im at it. So, my question is, will the 30200740 solid be too large for the following 318 engine spec or should I stay with the 10200703? I want to make some grunt with it but also want it to be streetable and not carry on like a stuck pig.

318 + 0.30" oversize KB 167
10:1 comp
Alloy heads with 2.02/1.60 valves (Aeroflow, Aussie brand with Eddies specs)
RPM air gap inlet
Good headers
Pertronix Ignitor III billet dizzy with matching coil
Carb/FITECH not decided but leaning towards the EFI
2500rpm stall max in a 904
I have either 3.45 or 3.9 gears sitting here, happy to use either

The car is not a daily driver and won't be covering long highway stretches. More used for a cruise around town with a trip to the qtr mile every now and then. Its going in our Aussie version of your 69 Dodge Dart.

Thanks in advance for any feedback.
Click to expand...

Hi vf 69 my build is close to yours besides your heads and manifold I'm running the EQ magnums with some port work performer manifold and matched runners. I run the comp Extreme energy 268 Solid nice street manners , nice lope ,runs like a scalded cat. Stage 2 A904 ,Stall is a custom 2500 , 3.45 lsd , You just got to be Honest with your intentions when getting one built and if they recommend a 3000-3500 it will be ok compared to an off the shelf. you just need to give all the specifics on motor ,gearing ,tyre size weight of vehicle and intended use ! and make sure you get that Distributor curved. One other thing if you get it Dynode just give the sheet to the converter guys and go from there otherwise you will need to give all engine specs. Choose wisely !
 
VF69HARDTOP said:
So to keep it more street friendly and maximise HP, am I then better off using something with a smaller duration but higher lift? This will keep the power band in the lower revs but maximise HP within that range, say 1500-6000rpm as an example.

If this is the case, should I be looking for something like this instead? How does the LSA affect a camshaft, is a smaller number better for street, say a 106 or is a 110 better?

Thanks
Click to expand...

Yes, on the first paragraph: more lift, less duration for better torque on the street. I would not say it will 'maximize HP'; people get misled by 'maximizing HP' if their objective is a responsive street cruiser. You can get a higher HP peak by going for more duration (the engine is breathing in more fuel and air), BUT that will reduce the low RPM torque and move the main RPM band of the engine up to higher RPM's and you end up with a narrower, higher RPM torque band. That is good for the track, but not what makes it a good cruiser engine; you want a wide, lower RPM torque band for that.

Wider LSA goes with lower RPM torque. Torque oriented cams have LSA in the 110-112-114 range.

IMHO, the later cams you list are getting closer. The cams like the XE268 kinda straddles the middle ground between torque cam and higher HP cams. My preference is for something narrower in duration to make even more torque down lower. My son and I used a Crane Z-268-H in his 340; the engine will probably never see a dyno but the predictions are right at 400 HP at the flywheel and almost 400 ft-bs of torque WITH good breathing engine parts. It is a better to have some good breathing heads, intake and exhaust manifolds than large duration cam for HP on the street; the good breathing part will make the same or more HP will less cam duration; that will give you both good HP and good lower RPM torque; i.e. a wider torque and power band. That is the ticket IMHO for the street.... but is not the ideal for the lowest ET's on the drag strip. It's a compromise when you want to do both.
 
if you don't have adj rocker arm already. I would stick with the Hyd cam.
less money less new parts to buy!
 
The hell with this automatic stall converter ****, go four speed. It sure makes Cam choices a whole lot easier
 
mopardude318 said:
The hell with this automatic stall converter ****, go four speed. It sure makes Cam choices a whole lot easier
Click to expand...

Unfortunately we only had the Borg-Warner 4spd manual boxes here and they can't handle a lot of power/torque plus manual V8 bell housings are harder to find. I originally had a manual box in the car but happy to just go auto now.

Cheers
 
nm9stheham said:
Yes, on the first paragraph: more lift, less duration for better torque on the street. I would not say it will 'maximize HP'; people get misled by 'maximizing HP' if their objective is a responsive street cruiser. You can get a higher HP peak by going for more duration (the engine is breathing in more fuel and air), BUT that will reduce the low RPM torque and move the main RPM band of the engine up to higher RPM's and you end up with a narrower, higher RPM torque band. That is good for the track, but not what makes it a good cruiser engine; you want a wide, lower RPM torque band for that.

Wider LSA goes with lower RPM torque. Torque oriented cams have LSA in the 110-112-114 range.

IMHO, the later cams you list are getting closer. The cams like the XE268 kinda straddles the middle ground between torque cam and higher HP cams. My preference is for something narrower in duration to make even more torque down lower. My son and I used a Crane Z-268-H in his 340; the engine will probably never see a dyno but the predictions are right at 400 HP at the flywheel and almost 400 ft-bs of torque WITH good breathing engine parts. It is a better to have some good breathing heads, intake and exhaust manifolds than large duration cam for HP on the street; the good breathing part will make the same or more HP will less cam duration; that will give you both good HP and good lower RPM torque; i.e. a wider torque and power band. That is the ticket IMHO for the street.... but is not the ideal for the lowest ET's on the drag strip. It's a compromise when you want to do both.
Click to expand...

Ill keep looking at different cams with under/around 230 @.050 duration, at least now I have a little better understanding as to what to look for.

Thanks for you help and to the other guys also.
 
67 gt said:
Hi vf 69 my build is close to yours besides your heads and manifold I'm running the EQ magnums with some port work performer manifold and matched runners. I run the comp Extreme energy 268 Solid nice street manners , nice lope ,runs like a scalded cat. Stage 2 A904 ,Stall is a custom 2500 , 3.45 lsd , You just got to be Honest with your intentions when getting one built and if they recommend a 3000-3500 it will be ok compared to an off the shelf. you just need to give all the specifics on motor ,gearing ,tyre size weight of vehicle and intended use ! and make sure you get that Distributor curved. One other thing if you get it Dynode just give the sheet to the converter guys and go from there otherwise you will need to give all engine specs. Choose wisely !
Click to expand...

Where did you get your stall built then? So does yours flash to 2500 with little flare as taking off form the lights normally?

Cheers
 
The 703 voodoo hydraulic is under 230 at .050 and is a good camshaft. That solid would act fairly reasonable as well.

Paralysis by analysis... great old saying! :)

Lots of inflated expectations from these small camshafts too. An XE268h or smaller flat hyd cam in a 340 with stock x heads isn't getting close to 400, no way, no how... If you port the heads and intake real good, then you have an opportunity. Seen way too many of them barely make 350hp and the timeslip MPH to prove it.
 
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