Anyone use Lunati mechanical flat 30200740?

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Mopar69gts

Mopar69gts

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Mesa az
Looking to swap out current comp. XE 268h
To this,
Lunati 740 specs
Adv. 264 / 272
.050 235 / 243
.526 / .546 lift w / 1.5r
110* LSA

Engine,
340 .030
Stock stroke
Srp flat tops 10.5
Trick Flow heads
1.6 roller rockers
Air gap
670 or 750 carb.
Doug's headers
2.5 exhaust out the back.
2100 stall converter
This is a daily driver on 91 pump gas
Looking for more power all around
Plus the Comp is a click small for 10.5
I can only put 30* total timing before it pings..
Plus the Comp is Noisy for a hydraulic
And not real crazy about hydraulic lifters these days..
I figure if it's gonna tick n tack at least it should make more power...lol
Has or does anyone run this cam?
 
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what's your quench distance?
what's the true compression ratio
do you have head flows
did you look at your burn patterns, any sharp spots, plug threads showing etc
 
I would think a little more lift would do a lot of good. Ever thought of calling up some cam grinders for some input? Give them that info with and they'd hook you up for about the same price.

Also- stick with the 750.
 
That will be a definite improvement over the comp joke cam! Lunati is far superior be it hydraulic or solid.
 
Wyrmrider said:
what's your quench distance?
what's the true compression ratio
do you have head flows
did you look at your burn patterns, any sharp spots, plug threads showing etc
Click to expand...
Quench. 044
10.4 on wallace calculater
Screenshot_20191127-094223.png

Wyrmrider said:
what's your quench distance?
what's the true compression ratio
do you have head flows
did you look at your burn patterns, any sharp spots, plug threads showing etc
Click to expand...
Plugs look good nothing funny goin on.
After calling Lunati their 740 cam is what was recommended.
The person said no real reason to have a Custom cam ground for my app..
Wyrmrider said:
what's your quench distance?
what's the true compression ratio
do you have head flows
did you look at your burn patterns, any sharp spots, plug threads showing etc
Click to expand...
 
Last edited:
mopowers said:
I would think a little more lift would do a lot of good. Ever thought of calling up some cam grinders for some input? Give them that info with and they'd hook you up for about the same price.

Thank you
I did call lunati and that's what was recommended.
I just wanted anyone's experience with it if possible..


Also- stick with the 750.
Click to expand...
 


I'm trying to understand the 2100 converter unless that's typo.

I'd also be a bit concerned about the LSA but that's a different topic.
 
yellow rose said:
I'm trying to understand the 2100 converter unless that's typo.
I had hughes performance
Rebuild a stock 998 converter
They made it a non lockup and raised the stall to approx. 2100 rpm or so.
Will at Lunati said it should be fine.
I usually put it in neutral at stops anyway.

I'd also be a bit concerned about the LSA but that's a different topic.
Click to expand...
It's on a 110 same as the comp.
Is your co concern because it's a mechanical cam or because it's larger?
 
Mopar69gts said:
It's on a 110 same as the comp.
Is your co concern because it's a mechanical cam or because it's larger?
Click to expand...


Usually the 110 LSA is a big compromise. Look through most any cam catalog and look at the most common LSA is. Do you think that's because that is optimal for most everything, or is there some other reason for it?

I'm in the camp that says its for some other reason, and performance ain't it.
 
first if you are running roller tip rockers go to the B3racingengines website and read all 4 tech articles
Lunati is a voodoo? check the lobes against lobes in their master lobe list
forget the lsa
where do you want your intake to close with your compression and gas
pick your other valve events and overlap requirements
LCA is a result- not an input but does indicate if you are on the right track
Those heads may require less timing than others and for sure less than stock - ask the questions what others are running
do you have cranking compression?
did you try to retard 4 degrees and see what happens (same as a bigger cam as far as intake close goes) does ping go away- if it does not then intake close difference may not solve your problem
you might try the .028 Mr gasket head gaskets- sometimes thinner helps
what yr says sometimes it's power brakes or bad headers/ exhaust
I take it you already own the roller tip rockers however at .525 lift Iron rockers work just fine
you could use more lift with those heads but you have already made the big jump
remember 106 or 108 would make the pingingworse if dynamic compression is the problem (with the same cam lobe)
take good notes and plot your timing
 
Wyrmrider said:
first if you are running roller tip rockers go to the B3racingengines website and read all 4 tech articles
Lunati is a voodoo? check the lobes against lobes in their master lobe list
forget the lsa
where do you want your intake to close with your compression and gas
pick your other valve events and overlap requirements
LCA is a result- not an input but does indicate if you are on the right track
Those heads may require less timing than others and for sure less than stock - ask the questions what others are running
do you have cranking compression?
did you try to retard 4 degrees and see what happens (same as a bigger cam as far as intake close goes) does ping go away- if it does not then intake close difference may not solve your problem
you might try the .028 Mr gasket head gaskets- sometimes thinner helps
what yr says sometimes it's power brakes or bad headers/ exhaust
I take it you already own the roller tip rockers however at .525 lift Iron rockers work just fine
you could use more lift with those heads but you have already made the big jump
remember 106 or 108 would make the pingingworse if dynamic compression is the problem (with the same cam lobe)
take good notes and plot your timing
Click to expand...


I agree LSA is a result not a target.

But when you see every grind on the same LSA you know that's a compromise and it's a compromise for the cam company to make money.
 
yellow rose said:
I agree LSA is a result not a target.

But when you see every grind on the same LSA you know that's a compromise and it's a compromise for the cam company to make money.
Click to expand...
Most tell you straight out that it is a compromise and that the 110 is a generic thing they put in every cam for the general hot rodder because it has a good sound.
 
You are giving up a lot with that 2100 stall converter. Even with that 268HE , I wouldn't want less than 3000.
 
forphorty said:
You are giving up a lot with that 2100 stall converter. Even with that 268HE , I wouldn't want less than 3000.
Click to expand...
Yes I'm sure,
I had a hughes 2500 in the previous 727
It launched better, but around town felt too disconnected to me.
I like the tighter converter for in town driving.

I changed gears recently from 3.23 to 3.73
Its much better.
 
My opinion is if that stall speed is right imo that does not match up to that engine unless its a 9.1 compression tow deal. What's the intended purpose of this build?,if it is street than you are a bit high on the compression,have more cylinder head and still too little stall than was needed. If it is performance than imo you need more cam and convertor,especially with the compression and trick flow heads. Lunati has the ultradyne lobes,I would call and talk to Steve and have them grind one on a 108 lobe separation and below is my recommendation for what I would want in that engine.

I NF70 266 239 158 0.3576 0.105 0.097 0.090 0.083 0.536 0.572 0.607
E NF62 270 243 162 0.3651 0.113 0.105 0.098 0.090 0.548 0.584 0.620
or:

I NF62 270 243 162 0.3651 0.113 0.105 0.098 0.090 0.548 0.584 0.620
E NF61 274 247 164 0.3727 0.117 0.110 0.102 0.095 0.559 0.596 0.633
 
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If trying to crutch the dynamic compression a bit I would prefer to have a cam on a 108 lobe separation installed straight up (108/108) than a 110 installed four degrees advanced on a 106,just my experience.
 
lead69 said:
If trying to crutch the dynamic compression a bit I would prefer to have a cam on a 108 lobe separation installed straight up (108/108) than a 110 installed four degrees advanced on a 106,just my experience.
Click to expand...
The Comp cam in it now is installed at 104
Advanced 2* (from 106 suggested. )
Cranking compression is 175 average
I know that probably has a lot to do with pinging on 91 and only able to put 30* total timing.
I could try retarding it at 108*
Just not real crazy about that cam.
That's why if I'm in that deep might as well replace it.
It's a driver I know the converter is tighter then most would run.
Maybe Solid flat is not the way to go.
I've had a few bad sets of hydraulic lifters within the last couple years is why I was thinking of going Solid.
The main reason for wanting to change cams is the noise. (Comp. XE.)
I've had mechanical cams that were quieter..
 
Mopar69gts said:
The Comp cam in it now is installed at 104
Advanced 2* (from 106 suggested. )
Cranking compression is 175 average
I know that probably has a lot to do with pinging on 91 and only able to put 30* total timing.
I could try retarding it at 108*
Just not real crazy about that cam.
That's why if I'm in that deep might as well replace it.
It's a driver I know the converter is tighter then most would run.
Maybe Solid flat is not the way to go.
I've had a few bad sets of hydraulic lifters within the last couple years is why I was thinking of going Solid.
The main reason for wanting to change cams is the noise. (Comp. XE.)
I've had mechanical cams that were quieter..
Click to expand...


I'm not so sure that 30 total is actually a bad thing. It could be, but it isn't always. I have no idea what you put 2 degrees more advance on the cam, but I doubt it is really killing you.

I forgot if you posted your CR but I know I'd rather run 30 total and have a higher CR than reduce the CR just to get 35 out of it. And who knows if you are actually at 30? Timing lights can and do measure differently from brand to brand and even light to light.

I'd also be interested in your tune up. As in what your timing curve, vacuum advance or not, spark plug etc.

I think at 175 cranking you may be able to work on the tune up a bit and get a bit more total. Also, if you have access to a different timing light, compare the hours to that one and see what the difference is. I trust reading a spark plug for timing way more than any timing light.

I hate to see you change the cam unless you hate it bad enough to justify the swap. I can say I'm not a fan of any off the shelf cam, from anyone so that would bother me.

But if it's just an issue of pinging and retarded timing, you may be able to correct some of all of that working on your tune up.
 
Mopar69gts said:
The Comp cam in it now is installed at 104
Advanced 2* (from 106 suggested. )
Cranking compression is 175 average
I know that probably has a lot to do with pinging on 91 and only able to put 30* total timing.
I could try retarding it at 108*
Just not real crazy about that cam.
That's why if I'm in that deep might as well replace it.
It's a driver I know the converter is tighter then most would run.
Maybe Solid flat is not the way to go.
I've had a few bad sets of hydraulic lifters within the last couple years is why I was thinking of going Solid.
The main reason for wanting to change cams is the noise. (Comp. XE.)
I've had mechanical cams that were quieter..
Click to expand...
I can understand about that cam,unfortunately all hydraulic cams make noise now including the high end stuff in my experience. I will say the cranking compression seems a bit low for a true 10.5 compression and that smallish cam but if anything that would be a positive as far as detonation. I am with Yr on really focusing on the tune even if you decide to go solid,seems to me there is something going on. One thing often overlooked is the carb,everybody focuses on ignition and compression/timing events and a carb can have a big effect.
 
yellow rose said:
I'm not so sure that 30 total is actually a bad thing. It could be, but it isn't always. I have no idea what you put 2 degrees more advance on the cam, but I doubt it is really killing you.

The reason I advanced it was it seemed a bit lazy on the bottom and only had 11.5"
Of vacuum at idle in neutral.
After moving it 2* adv. It got noticeably better on the bottom and vacuum came up to 13"
Now this was with stock x heads
And 9.7 compression



I forgot if you posted your CR but I know I'd rather run 30 total and have a higher CR than reduce the CR just to get 35 out of it. And who knows if you are actually at 30? Timing lights can and do measure differently from brand to brand and even light to light.
I do have 2 advance timing lights and both read the same.

I'd also be interested in your tune up. As in what your timing curve, vacuum advance or not, spark plug etc.
18* initial, plus 12* mechanical, 30* total mechanical.
All in at 2800 rpm
Yes vac. Adv. 10* more at cruise 40*
I've tried both manifold vac.
And ported.
Works best on man. Vac.
Firecore dist.
Fbo box and coil.
Autolite 3924 recommended by trick flow

I think at 175 cranking you may be able to work on the tune up a bit and get a bit more total. Also, if you have access to a different timing light, compare the hours to that one and see what the difference is. I trust reading a spark plug for timing way more than any timing light.

I hate to see you change the cam unless you hate it bad enough to justify the swap. I can say I'm not a fan of any off the shelf cam, from anyone so that would bother me.

But if it's just an issue of pinging and retarded timing, you may be able to correct some of all of that working on your tune up.
Click to expand...
 
Thank you all so much for the input.
And Good advice.
I think I will keep working with what I have for now anyway.
I really was just curious if anyone had used that Lunati 740 cam and their experience with it... I guess it's not a big seller
I hope you all have an Awesome Thanksgiving!!!
 
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