Torque = Driveability ? (Engine Masters LSA shootout)

[BSB67]

You didn’t answer anything specific from #16. Nothing.

You said:
“My cam is on a 105 and my wife can drive it anywhere”

Just tell us all about it, starting with the questions I asked earlier.

 

[Newbomb Turk]

You didn’t answer anything specific from #16. Nothing.

You said:
“My cam is on a 105 and my wife can drive it anywhere”

Just tell us all about it, starting with the questions I asked earlier.

Go read it again. Or ask specifically what I didn’t answer because I said I answered what I could.

Do you want me to give details like piston to wall clearance, P/V…what?

The TOPIC of this thread is LSA. That’s why I posted it.

 

[QuickDart360]

I had the mopar 280 cam on a 110° lobe separation and now have the 292 mopar cam on a 108° lobe separation and both had a lumpy idle. I seem to feel better torque from my 292. However, when I had the 280 it was straight up. My 292 is 4° advanced @ crank. Also had 3.55's with 280 now it has 3.91's. So those changes will influence as a whole for sure.

 

[MOPAROFFICIAL]

Every cam I've had custom ground I put in straight up and its sweet.. Every off the shelf cam I've ever used I've had to advance at least five degrees to get it cooking

 

[Newbomb Turk]

Can you tell us more about your cam, car, weight, et, mph, idle Rpm in gear, converter and gear?
Thanks

Ok, now that I’m on my iPad and not my phone and I can actually see what I’m typing I’ll try this again.

Cam: 281/281 255/255 .620/.620 105/105.
I’ll go back together with 155-160 on the seat and 355-360 on the seat.
1973 Dart Sport
3550 with my fat *** in it.
No ET or MPH with that iteration. I bent 3 valves because I screwed up so I pulled it down to check everything. I finally got the cam back today. Three lobes looked wonky. Hey were only down a few thou but they just looked funny so I sent it back to Racer Brown for a regrind.
950-1000 rpm idle but it will easily go down to 750. I don’t let anything idle that slow. It’s a stick so that’s the idle speed.
It was 11.55 or 11.75 compression, I forgot. Now it’s 12.2x on pump gas.
The pistons have been coated with Line2Line abradable coating.
3.09 first gear non OD gear box, 4.56 gear and a 26 inch tire. That was with the 8.75. I have a D60 now with 4.88’s and a 28 inch tall tire.
It had a fully ported Holley Strip Dominator with one 830. Now it will have a Weiand tunnel ram with two 830’s.
It had Hooker 5204 headers. 1.75 x 3 inch. Now it has Hooker 5303 headers which are 1.875 x 3.5 inch.
I had a Mallory Hyfire VI with a 29440 coil.
Now it has a Mallory Hyfire VII with a 28880 coil.
I had a Carter high volume mechanical fuel pump with 3/8 line.
Now I have a Mallory 250 GPH electric fuel pump with 5/8 line to the 4 port return regulator and 5/8 return.
McLeod Soft Lock clutch and 12 pound flywheel.
The gear box has a standard first gear, a pro shifted second gear and third and forth are slick shifted with synchros.
I had a Hurst Super Shifter III. Now I have a Hurst Ram Rod which is an inline shifter but not a vertigate.
I also upgraded to a dual range tach.
Milodon Super Stock pan with static pick up.
Iron heads I ported (going on the flow bench this Sunday) with 50 degree seats.
I use exclusively Torco engine assembly and cam lube.
I’ll break the engine in with Torco 30 break in oil. After the cam is in, I’ll spend the 40-60 minutes to break in the pistons, which should run at about .0015 clearance.
After some power pulls for data, the engine will come back off the dyno, I’ll pull the pan, install the crank scraper and windage tray, bolt it back to the pump and the make some power pulls to see what the scraper and tray make for power. Or save power which is more correct.
After that, I’ll spend the hour or more to dial in what the engine wants for a timing curve. Then I’ll spend possibly two or more hours to make the distributor have the curve the engine wants.
When all that is done I’ll make some power pulls to verify the timing curve is actually what the engine wants. If not, I’ll have to spend more time figuring out why the engine isn’t happy.
If it is happy I’ll change the break in oil out for Torco SR-5r Ow20 oil.
At that point I’ll start doing the rest of the tune up including lash loops, some more work on the timing curve.
When I’m happy with that, I’ll work on tuning the headers by adjusting primary and secondary tube lengths.

That’s all I can think of for now.

 

[Mopar Sam]

I have a Howards solid roller 251/257 @.050 640/640 on a 106 installed 1* advanced in my 414" sb Truck motor. 4.56 gear with 31"tires . It has too much low end for my liking. I had to pull my son's 88 shortbed with it when his fuel pump failed. I ended up taking off in 2nd from stop signs, (727 with Reverse vb) other wise it would jerk us to death. In fact I taking off in 3rd once, and it pulled fine, but I thought it may be abusing the 8'' converter.

 

[Newbomb Turk]

I have a Howards solid roller 251/257 @.050 640/640 on a 106 installed 1* advanced in my 414" sb Truck motor. 4.56 gear with 31"tires . It has too much low end for my liking. I had to pull my son's 88 shortbed with it when his fuel pump failed. I ended up taking off in 2nd from stop signs, (727 with Reverse vb) other wise it would jerk us to death. In fact I taking off in 3rd once, and it pulled fine, but I thought it may be abusing the 8'' converter.

I love it. Perfect example of the other side of drivability.

 

[RustyRatRod]

No, but she CAN drive it anywhere.

I drive it everywhere except for 200 mile trips.

My point is driveability is TUNING. If I posted my combo most guys would say it isn’t driveable because I’ve heard it a million times.

It idles clean, stays at not hotter than 170 on 100 plus degree days and thats only at stop lights and runs on pump gas at 11.5:1.

If my cam shows up this week I COULD be on the dyno in less than a month unless I get bogged down on pushrods.

It will have a tunnel ram this time, with two 830’s and it will be 12.2x on pump gas. I can’t remember the second digit.

And it will drive better than the last engine.

It CAN idle as low as 700 but I don’t let it get below 950 and would rather it’s 1k.

I certainly could change the gears and take it on a 200 mile drive. I don’t see it happening but I could do it.

When you say "pump gas" can you give an octane level? I believe you. I'm just curious. There is a guy over on The Hamb who has a 13.5:1 392 Hemi and claims to run on pump gas. He got beaten to death about it, but I believe him. It's just the way he talked about it and talked about tuning and so forth. Thanks.

 

[Newbomb Turk]

When you say "pump gas" can you give an octane level? I believe you. I'm just curious. There is a guy over on The Hamb who has a 13.5:1 392 Hemi and claims to run on pump gas. He got beaten to death about it, but I believe him. It's just the way he talked about it and talked about tuning and so forth. Thanks.

92 pump with up to 10% ethanol.

I’m pretty sure I could do 13:1 on pump gas but at some point you start flattening out the curve.

 

[RustyRatRod]

92 pump with up to 10% ethanol.

I’m pretty sure I could do 13:1 on pump gas but at some point you start flattening out the curve.

Probably with the ethanol, I bet you could.

 

[AJ/FormS]

Did they run those cams all at the same cylinder pressure?
If not
Then it's a bogus test.

 

[273]

Did they run those cams all at the same cylinder pressure?
If not
Then it's a bogus test.

How is it bogus, A lot of people on here seem to pick cam last, so kind of lines up how most would choose an LSA. Sure there probably be less of a difference if the 112/118 ran more cr, but again I don't hear many (anyone) saying you should bump up your cr when running a wider lsa.

 

[Newbomb Turk]

I think if they advanced/retarded the cams so that the intake closing points were the same, then it would should what the LSA really did. tighter LSA is going to build more low-end regardless because of the earlier closing point. Have the same cranking pressures would take that added factor out of the results.

It's like if they changed multiple parts on the engine at once...you don't know what "actually is responsible" for what. That's my dilemma, I'm building from scratch...so I'm not Handicapped by a set compression ratio, rear gear ratio or torque converter. I'm only handicapped by, heads, displacement, intake and the fact that I will NOT go to manual brakes.

The last one is a crippler. Chose your compression wisely, meaning stay on the low side.

 

[273]

I think if they advanced/retarded the cams so that the intake closing points were the same, then it would should what the LSA really did. tighter LSA is going to build more low-end regardless because of the earlier closing point. Have the same cranking pressures would take that added factor out of the results.

To me it should be tested how most would install it.

I didn't post it because this test told us anything surprising, we all know tighter lsa = more midrange torque. What occurred to me and found amusing most consider wider lsa with better driveability and more low speed torque also with better driveability but wider lsa obviously give less low speed torque so a bit of a contradiction. Why I have started to think for many reason that low speed torque don't = driveability.

It's like if they changed multiple parts on the engine at once...you don't know what "actually is responsible" for what. That's my dilemma, I'm building from scratch...so I'm not Handicapped by a set compression ratio, rear gear ratio or torque converter. I'm only handicapped by, heads, displacement, intake and the fact that I will NOT go to manual brakes.

That's the problem with a lot of test, what is a fair comparison ?

I don't buy cid automatically makes more hp eg.. 365 vs 408 but what is a fair way to test it ?
Exact same parts on both ? I don't think so, but if you use different cam, intake, ports etc.. what constitutes a similar level build with different parts ?

 

[Jersey Devil]

To me it should be tested how most would install it.

I didn't post it because this test told us anything surprising, we all know tighter lsa = more midrange torque. What occurred to me and found amusing most consider wider lsa with better driveability and more low speed torque also with better driveability but wider lsa obviously give less low speed torque so a bit of a contradiction. Why I have started to think for many reason that low speed torque don't = driveability.

That's the problem with a lot of test, what is a fair comparison ?

I don't buy cid automatically makes more hp eg.. 365 vs 408 but what is a fair way to test it ?
Exact same parts on both ? I don't think so, but if you use different cam, intake, ports etc.. what constitutes a similar level build with different parts ?

Driveability has Zero to do with Driveability. Hondas are proof of that...I don't know ANY Non v8 that has Tq N/A, lol.

I Definitely think people have Competely different meanings of "Driveability"

I can Guarantee, that more than a few cars on here that are driven on the Street I Don't consider Daily Driveable.

It's like the Pro-Mods that do the Hotrod Power- Tour. No they aren't dauly driveable to me. By their definition of driveability, the guys on here would consider my buddy's 565ci LBBC 6sec Top dragster, street driveable.

 

[AJ/FormS]

In a streeter;
Anytime you lose cylinder pressure, you will have to replace it with torque multiplication, so as not to be disappointed.
On the Street, you will only ever see absolute power one time, which is in first gear. By the top of second in a TorqueFlite with street gears , will get you to 80 or 90 mph pretty quick.
What I have always needed, is torque at 30/35 mph.
With street gears, that means either top of first or bottom of second. If the engine is down on cylinder pressure, it will be slow to respond and the zero to 60 is disappointing.
I really don't care about absolute power.
I just want the car to Jump, when I say go. which with 3.55s, is 3000 in Second or 4800 in first. If you don't have torque, you gotta go to first, and burn up the tires. Not really my style. Hammer down at 3000, chit better happen, and that takes torque, which takes cylinder pressure.

As a streeter, being on my third cam, I can tell you that ;
195psi is better than 180/185, which is better than 170 which is the absolute least I would run in my combo, and I'd be none too happy about it. I already know what I want in my next cam. I may be a slow learner, but I do in fact learn.

 

[273]

Driveability has Zero to do with Driveability. Hondas are proof of that...I don't know ANY Non v8 that has Tq N/A, lol.

I agree but doesn't stop people saying if you lose low speed torque driveability will go out the window, look at any 318 cam thread

I Definitely think people have Competely different meanings of "Driveability"

100%

I can Guarantee, that more than a few cars on here that are driven on the Street I Don't consider Daily Driveable.

It's like the Pro-Mods that do the Hotrod Power- Tour. No they aren't dauly driveable to me. By their definition of driveability, the guys on here would consider my buddy's 700ci 6sec Top dragster, street driveable.

My car ain't crazy, it's a 5.9l 380 hp Crate with 2.94 rear gears and a 2800 stall, driveability just fine even perfromance ain't bad obviously more gear and stall would wake it up. But seen many when talking about a similar 5.9l/360 combos on here people going how driveability will be trash and It's quite possible to them mine is but to me it satisfactory, it really depends on the person.

 

[273]

In a streeter;

I agree with you basic premise and always have. Agree you got to match the powerband, curve, rpms with with the general rpms you'll be at useable road speeds but some of your conclusions we differ.

Anytime you lose cylinder pressure, you will have to replace it with torque multiplication, so as not to be disappointed.

Like.. If you gain no VE% with the pressure loss sure, but you generally gain VE especially when starting from a low powered 2bbl engine. Example no reason a warmed over low cr 318 can't have a similar power curve as a stock low powered 2 or 4bbl 360. so both should have similar performance, even though the 318 loss V/P it gain enough VE% to flow similar air as the 360.

The VE%, volumetric efficiency gain was more than enough to offset the V/P loss, never see you factor that in.

On the Street, you will only ever see absolute power one time, which is in first gear. By the top of second in a TorqueFlite with street gears , will get you to 80 or 90 mph pretty quick.

True, but how do you gain the most power between 3500-4500 rpms ? More torque right ? well if you put peak torque especially at a higher lbs-ft per cid (usually means higher level of performance) at 4000-4500 rpm your gonna have the most available power there even though peak hp gonna be 1000-2000 rpms higher (5500-6500 rpm). Not saying you have to build the engine that way but higher peak power doesn't mean terrible low/mid power.

What I have always needed, is torque at 30/35 mph.
With street gears, that means either top of first or bottom of second. If the engine is down on cylinder pressure, it will be slow to respond and the zero to 60 is disappointing.

Yes less overall torque means less performance why the factory generally went up in step of 20-30 cid for the next level of power.

I really don't care about absolute power.

Agree, but does have an effect like I already explained.

I just want the car to Jump, when I say go. which with 3.55s, is 3000 in Second or 4800 in first. If you don't have torque, you gotta go to first, and burn up the tires. Not really my style. Hammer down at 3000, chit better happen,

True less torque there less performance there, why people like big blocks

and that takes torque, which takes cylinder pressure.

and or VE.

As a streeter, being on my third cam, I can tell you that ;
195psi is better than 180/185, which is better than 170 which is the absolute least I would run in my combo, and I'd be none too happy about it. I already know what I want in my next cam. I may be a slow learner, but I do in fact learn.

Was it just the psi or did Volumetric Efficiency play a role also ?

More fuel equals more potential, more V/P equals squeezing more out of that potential.
I could build a inefficient 440 to have a similar power curve as your 360 more than one way to make any curve.

 

[273]

I bet the 108 lsa setup would be the least street friendly behavior of the 3.

Unless you shrunk the duration to equal out the overlap like DV suggest.

I just want to find where " the line" is for me, btween daily driveable and Not.

If it's stumbling to run at 1/4 throttle below 3,000 rpms for me...that's a Fail.

Don't stray too far from stock.

I think most people on here aren't swapping a cam like this into a stock engine. I would guess atleast 1/2 have rebuilt their engine and changed piston(C.R.). I want to know how much a difference, a change in the C.R. with the wider lsa to maintain the dynamic C.R., cranking pressure would make.

I don't think many would change the cr to any huge amount for any one of these cams, A point of cr equals about a 3% power change, easy enough to guesstimate.

I know 100 degrees of overlap is going to do what I want.

Everyone has a different plan ideal, what the perfect engine" is FOR THEM. Even with the same heads/displacement, we MOST LIKELY need different cams. It could be for the differences in vehicle, wt, gearing, tires size transmission or driving style.

If it was that simple, there would one be one cam to choose.

If it runs right, but doesn't make the power I want...then It's time for some boost.

If it make the power, but I feel like it drives like ****...it's JUNK to me.

True

 

[Newbomb Turk]

I bet the 108 lsa setup would be the least street friendly behavior of the 3.

I just want to find where " the line" is for me, btween daily driveable and Not.

If it's stumbling to run at 1/4 throttle below 3,000 rpms for me...that's a Fail.

I think most people on here aren't swapping a cam like this into a stock engine. I would guess atleast 1/2 have rebuilt their engine and changed piston(C.R.). I want to know how much a difference, a change in the C.R. with the wider lsa to maintain the dynamic C.R., cranking pressure would make.

I know 100 degrees of overlap is going to do what I want.

Everyone has a different plan ideal, what the perfect engine" is FOR THEM. Even with the same heads/displacement, we MOST LIKELY need different cams. It could be for the differences in vehicle, wt, gearing, tires size transmission or driving style.

If it was that simple, there would one be one cam to choose.

If it runs right, but doesn't make the power I want...then It's time for some boost.

If it make the power, but I feel like it drives like ****...it's JUNK to me.

You’re kidding right? You think an engine that blurbles at 1/4 throttle and below 3k is a cam problem?

Not hardly. Thats 100% tuning.

It’s not 1975 anymore. You’d think by now guys would learn to tune.

 

[fishmens67]

When I’m happy with that, I’ll work on tuning the headers by adjusting primary and secondary tube lengths.

and then you'll put it in the car? or will you pull it apart again.
We talked about that several years ago, get it on the road before you can't.

 

[fishmens67]

5500 stall and 4.57 rear gear is what you want in a street Mopar, unless you prefer a 4spd with 4.88's. lol
If you're not knocking paintings off the wall or rattling windows ya mays well stick it back in the garage before you're waxed by a ricer. lol or a Chevy

 

[Newbomb Turk]

and then you'll put it in the car? or will you pull it apart again.
We talked about that several years ago, get it on the road before you can't.

lol then it goes in the car.

 

[273]

I would love to see that put to work, especially if you want to keep the top-end.
The howard's Hyd. roller cam they recommended me
241/247 @.050 on a 112 lsa, you would have to shrink it to a,
229/235 @ 0.050 on a 106 lsa to have the same overlap

Be interesting but don't see it keeping the top end, DV's idea seems instead of sacrificing lsa (midrange) for driveability sacrifice duration (top end).

and to maintain the dynamic compression the 10.36:1 static compression with the 112 lsa would have to dropped to 9.57:1 for the 106lsa.

I'd love to see a dyno comparisons of that. Might have to pay to do it so I can post it??

That would be kool

Also if you are building the engine from scratch, would would be building the to get in the 8<8.5 dynamic compression ratio, if you built it for the 106 and swapped in the 112 cam the engine would be a turd from the drop in dynamic compression.

I don't think turd is the right word, it might make less power but does that equal turd ?
Say someone runs manifolds instead of headers he'll make less power but is it a turd now cause he didn't run headers ?

Vise versa, if you had built the engine FOR the late Int. valve closing of the 112lsa, You would need to run race gas, if you dropped in the tight cam. The above cams, the 241 int closes at 48.5* @ 0.050 vs. only 36.5* ABDC for the 229 cam, thats a 12 degree difference.

There is no stock, I'm going from a '93 5.2L magnum with 9.1cr and a tiny 190'ish @0.050 on a 114lsa to a 390ci with 10.7cr and TFS 190 heads. I am WAY out of the Stock envelope.

I just meant if your really worried about driveability don't run a big cam.

From what I've seen depending on the engine above 220-229 ish is where you start really trading bottom end for top.

What's your power goals ?

 

[273]

From what guys run on here, I don't think 241/247 is Big, especially compared to what others are running in their combos on this forum. I do think it's a "little bit" too much than what I was thinking. I am more like going to start in the mid 230s /low 240s durations, but with one of their more aggressive lobe profiles. They already said the TFS hyd. roller springs are prefect for their faster lobes.

Depends what your trying to accomplish, If your car ain't super heavy and willing to run decent gears and the right stall, I don't see why 241 with a TF 390 won't work. But if your trying to run fairly high gears with less than adequate stall especially with a heavier car than ya you might want a little less duration.

My guess that cam 241/247 with a TF 390 will make peak power at or slightly above 6000 rpm and torque at 4500-5000 rpms.