chinese 1.6 steel roller rockers & RHoads lifters

[forphorty]

Well AJ , I could be wrong, but I wouldn't expect a 220ish at .050 with 110 LSA in a 360 to be super fuel efficient at 1300 rpm , fast rate or not. That might be asking too much. Sounds like it was a great overall package though.

 

[AJ/FormS]

Well AJ , I could be wrong, but I wouldn't expect a 220ish at .050 with 110 LSA in a 360 to be super fuel efficient at 1300 rpm , fast rate or not. That might be asking too much. Sounds like it was a great overall package though.

You're not wrong.
I had to increase the cruise rpm to over 1600rpm to get high 20s mpgs in point to point running. I could tell you it got 32mpgs on one particular trip, but com'on nobody believes that.lol.
And yes it was a pretty good package, for quite a long time. Especially with 4.30s.
Eventually thou I got tired of HAVING to always split gears, on account of the engine wasn't fond of the A833od shift splits on their own which as you know are quite far apart. And splitting the GVOD at low rpm/part-throttle, the GVOD is not particularly accurate, and getting the clutching just right got to be a pita.
So when the lobes fell off the cam, I moved on; bought a smaller DD, and switched the car from DD to weekend warrior; and mpgs was no longer on my mind.
It was a great combo, for most of the time I had it.
Now, with the combo changed yet again, it's waaay better,lol.

 

[Wyrmrider]

aj
I used .275 cus the jones cam peaks around .305 and the DC 260 cam less than 300 so I can't use .300
I have the complete cam doc printouts and .275 made the most sense
where the piston is really pulling on the intake charge around max lift (and later)
.200 is also interesting
at.050 the DC cam is longer than jones and much longer at .004 and seat to seat

 

[Krooser]

Mike Jones .904 grind is really short seat to seat eventhough it's listed at around [email protected] It's 60+ @.275 which is 50% larger than the Mopar Perf 260
I'd like to compare with the Howard's

He can grind it any lsa you want- gives a really flat torque curve I posted a 364 AMC dyno sheet recently

BTW AMC Rambler came with 3'31 with OD with 3.54> 4.11 and even 4.28 optional
we used 3.08 and high 2's in the Mobilgas economy run with the Nash Statesman flathead
If you go over a hill below the OD low limit you can take your foot off the gas and it will not shift into OD so you can coast shut the motor off...

Jim,

It's likely you and I are the only two here old enough to remember the Mobilgas Economy Run... hahaha!!!!!!

 

[yellow rose]

Jim,

It's likely you and I are the only two here old enough to remember the Mobilgas Economy Run... hahaha!!!!!!

Nope. I remember that. Was going to do it in 1980 but I had to go to Canada instead.

Maybe it wasn't the Mobil gas thing but it was close. I can't remember the exact name of that thing. No offense to Canada but I'd rather have not went and done the MPG test.

 

[AJ/FormS]

Mike Jones .904 grind is really short seat to seat eventhough it's listed at around [email protected] It's 60+ @.275 which is 50% larger than the Mopar Perf 260

I used .275 cus the jones cam peaks around .305 and the DC 260 cam less than 300 so I can't use .300
I have the complete cam doc printouts and .275 made the most sense
where the piston is really pulling on the intake charge around max lift (and later)
.200 is also interesting
at.050 the DC cam is longer than jones and much longer at .004 and seat to seat

Lemmee see if I get this right.
The .275/.305/.300/.200 numbers are all lobe-lifts numbers. And the Jones has just a lil more lift than the DC.
Are you saying if I overlaid the profiles like sinewaves, the Jones cam would have plenty more lift per time in degrees,yet slams the door within a few degrees of the DC, and then continues to slam shut to on the seat far earlier than the DC?
I'm liking this Jones' idea so far.

So in terms of degrees at around .275 lift, the Jones cam is behaving like a bigger than 256 cam, and bigger than a DC 260, right? What then does it compare to?
Or in other words could a guy expect more power from a Jones 256, than someone else's 260/264/268 or?
And if Jones has a 256 like this, do they also have a 268 that behaves like some smaller cam at the seat to seat and or even at .050, cuz that is sounding real interesting.

 

[RustyRatRod]

@greymouser7 John, some of these guys seem to think it won't be so bad, so go for it man. It might work ok. My opinion I was basing on the numbers alone. They don't add up well. What's the worst that can happen? You need to find another gear set? That sure won't be the end of times. Go for it and see what happens.

 

[AJ/FormS]

Look what I found...
Series for.903″SolidLifters
These profiles are for use with Mechanical Flat tappets with an .903″ diameter or larger. The EMV series profiles are for use in racing applications only, and require the use of our Centra-Lube lifters.

Part # / @ Seat/ .050″/Lifts of 1.5/1.6

CM70325Y/ 280°/230°/.325”/.470”/.500”

CM71375 /284°/238°/.375″/.544″/.580″

CM73375 /292°/246°/.375″/.544″/.580″

CM74375 /296°/250°/.375″/.544″/.580″

CM75405 /300°/254/.405″/.589″/.628″

CM76360-10/304°/250°/.360″/.525″/.560″

Looks like the first lift figure is lobe-lift and the others are net after .020 lash; I'm guessing
Check out that 71375. If that is correct, then that's 46 degrees from .050 to on the seat! Man that's fast
Hey Wyrmrider, what DC cam might you have listed at 284 seat to seat?lol

I couldn't find hydros

 

[yellow rose]

Look what I found...
Series for.903″SolidLifters
These profiles are for use with Mechanical Flat tappets with an .903″ diameter or larger. The EMV series profiles are for use in racing applications only, and require the use of our Centra-Lube lifters.

View attachment 1715341118

Part # / @ Seat/ .050″/Lifts of 1.5/1.6

CM70325Y/ 280°/230°/.325”/.470”/.500”

CM71375 /284°/238°/.375″/.544″/.580″

CM73375 /292°/246°/.375″/.544″/.580″

CM74375 /296°/250°/.375″/.544″/.580″

CM75405 /300°/254/.405″/.589″/.628″

CM76360-10/304°/250°/.360″/.525″/.560″

Looks like the first lift figure is lobe-lift and the others are net after .020 lash; I'm guessing
Check out that 71375. If that is correct, then that's 46 degrees from .050 to on the seat! Man that's fast
Hey Wyrmrider, what DC cam might you have listed at 284 seat to seat?lol

I couldn't find hydros

Those ramps are considered slow by today's numbers.

My cam is 281 seat to seat and 255 at .050 with a .010-012 lash.

 

[AJ/FormS]

Those ramps are considered slow by today's numbers.

My cam is 281 seat to seat and 255 at .050 with a .010-012 lash.

Well then mines a dinosaur; it doesn't even list seat to seat

 

[RustyRatRod]

Yall I think John already has his camshafts in hand, so all this is a moot point.

 

[nm9stheham]

Yall I think John already has his camshafts in hand, so all this is a moot point.

Well, maybe he can chime in and say which. They can be sold. And I agree on the rear gear change later..... but I'd start with the best cam for this app to give it the best shot. For low RPM torque and mileage, LSA need to be pushed towards 114*.

 

[nm9stheham]

Well then mines a dinosaur; it doesn't even list seat to seat

Hey AJ, download the Howard's Master Lobe list to seek that fast ramp solid; it shows durations for 'seat' (.006" for hydraulic and .015" for solid), .050", and .200". Plus go down about 3/4 of the way and it will show profiles specifically for the .903" Mopar lifter, both hydraulic and flat.
Downloads | Howards Cams

You're gonna see some very small 'seat'-to-.050" duration differences. These are all 'orderable' through normal sales channels. (I spoke with their customer support a few months ago and it sounded like they prefer you to order through a standard sales outlet.)

 

[yellow rose]

Hey AJ, download the Howard's Master Lobe list to seek that fast ramp solid; it shows durations for 'seat' (.006" for hydraulic and .015" for solid), .050", and .200". Plus go down about 3/4 of the way and it will show profiles specifically for the .903" Mopar lifter, both hydraulic and flat.
Downloads | Howards Cams

You're gonna see some very small 'seat'-to-.050" duration differences. These are all 'orderable' through normal sales channels. (I spoke with their customer support a few months ago and it sounded like they prefer you to order through a standard sales outlet.)

Damn. Howard's has some pretty nice lobes for the .904 lifter. Very close to the Comp MM series and the Racer Brown lobe I'm running.

 

[AJ/FormS]

Thanks nm9, but I don't see anything close to seat to seat; With the .006 spec there could be another 10/15/20 degrees hiding in there, from .006 to closed and not leaking; and nobody knows until you install it and measure it..
That was my point, to get away from that unknown. I know it don't count for much anywhere except fuel economy, idling down the hiway. With 230 or more at .050, that doesn't leave a lot of time for scavenging, and if the exhaust valve takes another 10 or 20 to close, then you're getting down to 90* of scavenging, and so a whole lot of energy is going right out the exhaust. That's what I want to get away from. A wide LSA just aggravates that even more.Yeah, I know closing up the LSA increases overlap. So it becomes a balancing act. Trading one economy-loser for another. That's what makes choosing cams so much fun.
If I swap cams it will be to a solid; then I'll know exactly when the valve is closed. I shouldda done that from the get-go, as often as I have played with my hydros. I thought I could strike a better balance with hydros; power with economy, but in any case not with the HE3037AL,even with 180plus psi.Hey, maybe I'll convert my hydros to solids and see what happens. Yeah I think I could sacrifice some lift and duration.........

 

[Wyrmrider]

Jim,

It's likely you and I are the only two here old enough to remember the Mobilgas Economy Run... hahaha!!!!!!

Lotta fun for a high school kid sweeping up at Ricker Motors in Whittier- which was in a (large) gas station- inside shop though
we found a way to run skinny tires on the "optional" 15 wheels
lotta pressure

Mechanix Illustrated and Mail for McCahill

 

[nm9stheham]

Thanks nm9, but I don't see anything close to seat to seat; With the .006 spec there could be another 10/15/20 degrees hiding in there, from .006 to closed and not leaking; and nobody knows until you install it and measure it..
That was my point, to get away from that unknown. I know it don't count for much anywhere except fuel economy, idling down the hiway. With 230 or more at .050, that doesn't leave a lot of time for scavenging, and if the exhaust valve takes another 10 or 20 to close, then you're getting down to 90* of scavenging, and so a whole lot of energy is going right out the exhaust. That's what I want to get away from. A wide LSA just aggravates that even more.Yeah, I know closing up the LSA increases overlap. So it becomes a balancing act. Trading one economy-loser for another. That's what makes choosing cams so much fun.
If I swap cams it will be to a solid; then I'll know exactly when the valve is closed. I shouldda done that from the get-go, as often as I have played with my hydros. I thought I could strike a better balance with hydros; power with economy, but in any case not with the HE3037AL,even with 180plus psi.Hey, maybe I'll convert my hydros to solids and see what happens. Yeah I think I could sacrifice some lift and duration.........

OK, I thought you were speaking of the .006" spec as essentially the 'seat' point. Not sure what to say... at some point between .000"
and .006" lift the flow is essentially nil even with some scavenging.. which is going to be low under 2000 RPM anyway. So it is somewhere like 0-10-15 degrees extra, not 10-20 IMHO.

And for comparison, what else are you going to compare it to? 30 degrees overlap at .006" is a far cry from 50-60-70 degrees overlap at .006".

As for the solids.... I am looking at these Howards .903" lifter solid profiles for my next build. They look pretty nifty!

 

[Wyrmrider]

AJ wrote yesterday

I get sorta what you are saying, but what is .275? and if you compare another cam at .275 what might their .006s be?

And IIRC that Mopar 260 is speced at .008 is it not? so is there some unfair comparison going on there; I mean 60* is HUGE.



Jones and Comp and Lunati/ Howard are at .006 and MOPAR uses a completely different method but a Mopar 260 @.008 Is close to mid 260s for the others @.006 and like a 268 Crane And SAE at .004



but that's not the point



Your next suggestions are done easily with overhead cams or a jumbo lifter

and easier to do with solid lifters

actually not as easy with a short roller (except with inverse radius flanks)

If you have your head flows ask Jones to run your ideas through his computer (or buy a copy from Rick Jones) and have him grind you one

Rick can provide a lift table that can be ground by let's say Howard but advice from Mike is priceless

right Kooser?



At that time Hughes did not publish an advertised = was this an ENGLE? You can get specs from Engle and they do not push the limit nor does MP meaning they live well

you can go for more acceleration if you rally blueprint your valvetrain



Aj post 31



You got that right

seat to seat the jones is shorter than the DC 260 by a bunch

This threw me off for a long time

Jones .202 @.50 is shorter than some other [email protected] cams which can be .205

A priory I would have thought (and did think)the Jones would have been bigger

The reason is the jones starts of shorter @.002 and @ .004 and is still shorter at .006 and .050

but at .100, 200, .275 it is way bigger



Remember this lobe was developed especially for low compression Mopars

short seat to seat to build cylinder pressure and big around the ICL to give great fill

Asymetrical so it shuts the valve quickly then gently



Right? Right! Comparing .200 degree duration data gives you a clue .275 really shows

and how he does it without a little pointy (chevy style) nose is a mystery to me

AFIK jones does not have a 268 but he does have solids

and as I said above he may also be able to generate a lift table for a computer controlled grinder



AJ I just moved (actually last December) and all that stuff is packed away

just guessing here but I think the Jones 256 cam is down in the 240's seat to seat

284 @.002 is going to be a big cam

You can look at some Cranes at .004 easily

We know the 440 Magnum cam is way over 300 and the 340 cam close to 300 seat to seat

I used to run a Herbert that was .400 seat to seat- but then you could adjust the lash all the way to .030 to make a shorter cam out of it if you had the traction

 

[AJ/FormS]

Wyrmrider
Hyup That's what I was suspecting; Thanks for your insights.

 

[yellow rose]

Life would be less complicated if the cam grinders would publish the seat to seat, at .050, .200 and maybe .300 lift duration numbers.

That way, you could look at...say 3 or 4 280 seat to seat cams and then see what they look like as the slower lobes get caught and passed up by the faster lobes.

 

[Wyrmrider]

or even SAE .006 at the valve numbers
Solids being net of lash
of course sometimes slower lobes are better (but you cannot tell by my usual posts as most builds are not for longevity/
I usually do not consider .050 useful except to determine "intensity" or for timing/ installation
of course intensity is changed by the "advertised" duration listed and with solids on the lash vs advertised (sometimes .020) duration
That's why SAE works
then add in flow and piston demand (including rod ratio) as some of the good simulation programs do

 

[nm9stheham]

I have to think that .004" or .006" is the real number to use, for a good reason: below those lifts, or SOME small lift (for a hydraulic), the flow in or out is just so small as to not make any meaningful contribution to the engine operation. 10 or 20 degrees at essentially zero flow is still essentially zero flow.

I'd suspect (hope?) that was the judgement made by the Chrysler engineers, and the lift used to spec their version was based on what they thought was the lower limit of meaningful flow.

 

[AJ/FormS]

I have to think that .004" or .006" is the real number to use, for a good reason: below those lifts, or SOME small lift (for a hydraulic), the flow in or out is just so small as to not make any meaningful contribution to the engine operation. 10 or 20 degrees at essentially zero flow is still essentially zero flow.
I'd suspect (hope?) that was the judgement made by the Chrysler engineers, and the lift used to spec their version was based on what they thought was the lower limit of meaningful flow.

Except on the intake side,at low-rpm, the piston is coming up on compression perhaps half way, up or beyond, and that stinking intake valve is still not sealed. So the piston is pumping A/F charge back into the intake. That makes for lousy fuel efficiency. Between that and the early opening exhaust, you just cannot cruise at low-rpms and expect fuel economy.

 

[Wyrmrider]

yep long intake close is a Dynamic compression killer
problem at overlap is not so severe
but slow exhaust opening bleeds power (especially on low compression motor) and torches exhaust valves and seats
at high pressure even a small opening has flow
Aj nails it

 

[RustyRatRod]

@greymouser7 John, is any of this BS doin you any good?