1.6 Rocker Arm Performance Gains over 1.5 Rocker Arms

-
would you have enough valve clearance with the pistons you have in the engine?
what about clearance between the bottom the spring retainer and top of the valve guide?
coil bind?
 
would you have enough valve clearance with the pistons you have in the engine?
Rocker arms with more ratio change overall max lift. They have a very small impact on rate of lift and duration. Therefore valve to piston contact is of almost no concern when switching between 1.5 and 1.6 ratio.
 
Car leaves well for the et/mph. 105 mph in the 1/4?

It's losing power up top. Should run around 107-109 with that 60'. Losing about 2 tenths at 8th pole and 3 tenths at the 1/4 pole.
 
I believe that FT cams [ lobes ] are 'maxxed' out. Unlikely to see new lobes. FT lobe lift & rate of lift is governed by lifter OD: go too radical on the lobe & the edge of the lifter digs into the lobe. You do not have this restriction with roller lobes.
Comparing the OPs Hughes 050 & lobe lift #s to Crane & Bullet 0.904" lobes, they are almost identical, which suggests the Hughes lobes are already high rate, high lift.
 
You need a bunch more than 1.6 rockers to drop .7 at the 12.50 range. You need more camshaft and compression, and that may not be enough. Possibly more cylinder head. That’s if the car is sorted fairly well and you’re not dumping a bunch of ET in the short times.
TT5.9mag, I'm considering a lot of different options. Compression, Cam, E85, Cubic inches.... Just trying to understand all this newer tech that is sooo different from the 80's & early 90's.
 
Sorry, I didn't mention that exactly. Comp ft lobes are maxed out. "Old grind", not likely.
I haven't put a ft cam in anything in years! I don't know anyone that has either... I was referring to a quick ramp hyd rlr. I obviously didn't mention that after rereading my post.
Also, with any hyd cam, a modified oiling system (ported) is a requirement for max perf, as is not running any more spring pressure than necessary, to keep loss of lift/ duration minimized due to bleed down. I also use limited travel lifters on all of my performance hyd rlrs. My serious stuff is solid rlr.
TIMINATOR
I have( solid cam) I think the failure rate of them is the most over picked on thing there is.
Make sure the lifter bores are good, make sure you properly lube the lobes, get it to start right away, your gonna be good nearly all the time.
My whole life never had a flat tappet cam failure.
Hydralic rollers aren’t my cup of tea, heavy, no thanks. Guess I am hard core old school, but if it don’t stink, don’t stir it.lol
 
TT5.9mag, I'm considering a lot of different options. Compression, Cam, E85, Cubic inches.... Just trying to understand all this newer tech that is sooo different from the 80's & early 90's.
IMO, the new tech is old tech really but just pushed a little further on its limitations. Since the camshaft is the main topic spoken here, I’ll roll with that.

With the introduction of better equipment in the industry and it’s getting better all the time, the previous mentioned spintron helps a lot.

The ability to customize the lobe and push the lobe grind in directions and shapes like never before has helped a huge amount in getting aggressive with its design while also testing the valve train along with it.

It is my opinion that I honestly think that a custom cam can be ground for you without touching the heads for further power in order to drop your et.

The cam will be more focused on the task at hand.

Previously someone mentioned getting a Comp Cam. IF you can get to a actual cam designer there, your good.

But this is also why I mentioned Schneider cams. (Or other grinder of your choice.) It’s easier to speak with a grinder direct for a custom grind. While I like Comp Cams, never having a problem with there material, bigger companies can be a PIA.

Whatever route on a camshaft you take, my suggestion is to start with the cam.

Overall, it looks like your doing pretty good with what you have now and I think minor tweaks is all it will take without E85 or stroking the engine.

I’d refocus on what you have now and what could be easily replaced or massaged. Things like a better exhaust system, ported and matched intake manifold, even spark plugs. Heat range, gap, etc. The cars weight? Suspension & tire size.

Have fun!
 
I haven't put a ft cam in anything in years! I don't know anyone that has either...
i use SFT with great results. SFT get shunned by people that don't know how to break the cam in. follow the instructions and everything will go smooth. simple as that
 

I think simple ROT is if you're undercammed it will likely make more power, if you're not, it probably won't...

if you had a cam like this one: More Information for MELLING SPD22 or even this one https://www.rockauto.com/en/moreinfo.php?pk=10211292&cc=1435034&pt=5260&jsn=541 you might make more power going from stock rocker to 1.6 roller rockers.

Here’s the thing, while you are potentially right, actual gains may not translate into anything meaningful.

A lot has to do with how well the cylinder head flows. On a stock head where we will say good flow lifts fall after .500, exceeding that lift doesn’t help as much as you will hope it does. The more lift past the stall or point of flow rate tanking will not add anything worthwhile.

If the cylinder head can support the flow of the higher lift, the gains become more better and possibly worth talking about.

The other half is the duration of the cam. A quick blip valve opening of a small cam is vastly different than a longer duration cam.

At 209 or 224 intake duration, the gains seen between those two cams could be a notable gain but will be a laughing stock in a comparison of a cam with 255/260 and better duration but still may not be what you think.

The faster action of the valve movement is a nice plus but as above….

The last thing is, this is all engine dependent. Every last aspect of it.
 
Cam: Hughes old grind HE3038AL 230/236@050 .515/.535 110* lsa with 1.5 273 rockers. 1.6 would yield .552/.571.
In my 367/4-speed Barracuda, I run that exact cam.
with 1.6s and OOTB Edelbrock heads@ 11.1 Scr, and about 185 CCP.
Car goes 93 in the Eighth, also at 7.92 but with a 2.2 60ft ,on Drag radials, with 3.55s, shifting at 7000. Yes the tach was on 7000 almost the entire trip. Weight was 3657 with me at 200.
Only ever got the one good pass on an old airport runway. Was only there for the ticket.
That cam has been in the engine since 2004.
 
I think increasing the rocker ratio it will add power. No idea how much. Unless you are controlling all the variables at the track and the car is consistent within a few hundreadths, you might not know for sure if or how much it helped. Only you can decide if it is worth it.

I encourage trying stuff irrespective of popular belief. That’s how you learn. You just need to have balanced expectations.

I do find it interesting that most Mopar enthusiasts so embrace the fast rate cams, but not higher rocker ratios. The increase in max lift is not a meaningful part of the increased rocker ratios but the increase duration the valves sees at each lift point. Again, I cannot make any claim as to the improvement or its value.
 
Last edited:
I think increasing the rocker ratio it will add power. No idea how much. Unless you are controlling all the variables at the track and the car is consistent within a few hundreadths, you might not know for sure if or how much it helped. Only you can decide if it is worth it.

I encourage trying stuff irrespective of popular belief. That’s how you learn. You just need to have balanced expectations.

I do find it interesting that most Mopar enthusiasts so embrace the fast rate cams, but not higher rocker ratios. The increase in max lift is not a meaningful part of the increased rocker ratios but the increase duration the valves sees at each lift point. Again, I cannot make any claim as to the improvement or its value.
Myself it's not that I would not increase rocker arm ratio or consider it as a good performance upgrade it's just that with most factory type heads push rod clearance through the head is already approaching a issue with a true 1.5. so I'm taking that in consideration when considering the ganes that will be made with a 1.6.jmo. within a factory/Edelbrock/la style head I like to keep my lift under or around .550 and work on my low and middle lift flow numbers.
 
Hard pass on the nitrous... E-85 is about as kinky as I'll get. :thankyou:
Some folks love it, but I hear you. Your compression is really too low to benefit from running E85, and you would have to increase your fuel flow and change the carb, no?

How about installing a solid roller spec'd by Dwayne Porter or AndyF?
 
Some folks love it, but I hear you. Your compression is really too low to benefit from running E85, and you would have to increase your fuel flow and change the carb, no?

How about installing a solid roller spec'd by Dwayne Porter or AndyF?
Oh believe me.... If we go E85, we'll be at at least 12:1....with scat rods and air gap intake with E85 750 DP.
My son is really good at Holley E85 conversions. (pretty good engine builder too)
 
Oh believe me.... If we go E85, we'll be at at least 12:1....with scat rods and air gap intake with E85 750 DP.
My son is really good at Holley E85 conversions. (pretty good engine builder too)
Sounds great. I missed that you were doing a complete build, but it sounds like you have the bases covered. Best of luck!
 
You only gain about .30 lift and you need to measure push rods for sure. Don’t buy prw rockers they are junk I have a set. It breaks the adjuster screws.
 
You only gain about .30 lift and you need to measure push rods for sure. Don’t buy prw rockers they are junk I have a set. It breaks the adjuster screws.
Probably go with Mancinni Racing Brand Harland Sharpe rockers. Ratio TBD
 
It does run pretty well, 12.50's. The rear main is starting to drip more than i'm comfortable with. Going to pull the engine and go through it and looking to go 11.80 - 12.00 and run in Sportsman class next year.
Great to hear you want to come and run in the Sportsman class. Come join the fun where no electronics are allowed. Oh wait, the Teslas have traction control and lots of other controls and are allowed. Sorry - I digress....

Seriously, if you're willing to spend upwards of $800 for rockers, then I'm obviously biased but why not spend double that or a bit more and stroke that engine? If you want some serious improvement, keep the shift speeds down for longevity, and a torque monster, there's nothing like a stroker. If mine can run 11.0x's with a streetable 408, so can anybodys. And yours would be 340-based instead of 360-based so maybe a bit more performance. As for cam, I use a Bullet SFT but I intentionally left some performance on the table when I chose the "middle of the road" Ford lifter diameter for my lobes (Mopar is biggest, Ford is middle, GM are smallest). This reduces the load on the valvetrain and makes it virtually maintenance free with ample margin for any over-revs due to whatever causes. My $.02...
 
-
Back
Top Bottom