[Skip Fix]

With as good a results as the Ultradyne cams got, even with Butler using them as his main go to cams(before Harold and the IRS got sideways and shut it down) I still don't know why more guys are not still using them. Bullet has them even Lunati has them as Harold did a tent there(when I got the 296/304 in my pump gas motor).

FWIW with an US 304/312 on a 112 in my RAIV 400 Rhoads did not help vacuum any or improve bottom end and even regular lifters ran power brakes fine. They were so noisy , and would bleed down even when trying to set them(start at zero tighten more then it would feel almost as loose as at zero from bleed down) I replaced them.

[ponyakr]

"...Rhoads did not help vacuum any or improve bottom end and even regular lifters ran power brakes fine. They were so noisy , and would bleed down even when trying to set them(start at zero tighten more then it would feel almost as loose as at zero from bleed down) I replaced them."


Cliff, when you read this, please tell us how many problems you've had with Rhoads lifters. I used many sets, and never had a single problem with any of 'em.

[General Z]

Thanks to the people here, I pulled the XE262H out of my 469 and put in a Summit 2802 and never looked back.

The XE262H scorched off the line, but things were never quite right.

[Skip Fix]

My Rhoades were louder than my solid flat tappet and solid roller cams. Set the valves then go back around and all feel loose like they had no preload as they had bled down with the motor being off and no oil pressure while setting. Other than that they ran OK. I used them as I was racing in a class with a vacuum rule-they did not increase it any for me, so why use noisier lifters that did not help my idle vacuum was the reason I dumped them.

[Cliff R]

I like and use Rhoads lifters on flat tappet hydraulic camshafts as we pick them very carefully for our engines to make optimum power on pump fuel.

Never once had the first problem with them. They are very well made parts and easy on the cam as well.

There are some applications where you really woln't see a big performance gain, but you will see improved idle quality, usually about 2" vacuum improvement at idle speed. They will make some noise at idle and low Rpm, so if you can't deal with some "ticking" at idle speed I would avoid them......Cliff

[STEELCITYFIREBIRD]

I have a set of original Rhodes in a healthy cammed 428CJ FORD with dual quads. Being an auto trans car with power brakes, they provided a definite increase in idle quality in gear,idle mixture adjust-ability (reaction to idle mixture screw adjustment) and idle vacuum. Also an increase in low end torque...a welcomed improvement over the same cam with standard lifters. The valve train sound is very similar to a solid lifter cammed engine.I like them in this application!

[rtanner]

ive got the ra-4 rhoades 1.65 combo right now, about my 5th time to use it, im seriously considering getting comp to grind me a 305 magnum on 114, then putting rhoades on it, i tried that cam when i was a newb back in 1977 and it had 0 till 3k in a 400, but once i got it rolling it would make 396 chevelles cry, w 455 cubes some compression and a wide lsa w rhoades it might perform well.

[ponyakr]

"...im seriously considering getting comp to grind me a 305 magnum on 114, then putting rhoades on it..."




Back in the late '80's, Comp made a cam with the 292H Magnum lobe on the intake, and the 305H Magnum on the exhaust. I put one of these in our 2nd gen 455 bracket engine. With Rhoads lifters, it would still idle good enuff and make enuff low end power to leave from an idle, with a stock converter. But, the engine had 72cc iron heads on it. So, I don't know how that cam would have done with less than 10:1 CR.

Anyhow, if your gonna buy a custom cam anyhow, you may wanna get 'em to make it a dual pattern.

[PAUL K]

Originally Posted by rtanner

ive got the ra-4 rhoades 1.65 combo right now, about my 5th time to use it, im seriously considering getting comp to grind me a 305 magnum on 114, then putting rhoades on it, i tried that cam when i was a newb back in 1977 and it had 0 till 3k in a 400, but once i got it rolling it would make 396 chevelles cry, w 455 cubes some compression and a wide lsa w rhoades it might perform well.

That would be an interesting test. A friend of mine uses the 305H ground on a 108 and has run 11.6 @ 116 mph using 1.5 rockers, B&M 2500 rpm converter and 3.36 gears.

[Cliff R]

There is no "playing it safe" by selecting a SCR at or less than 9.5 to 1, when you come along and put a really small cam in the engine on a tight LSA with really quick ramps designed to improve cylinder filling and improve low end power. That's what this thread is about, making piss-poor cam choices for HUGE engines with moderate compression. You can get into trouble very quickly doing this, and leave a BUTT LOAD of power on the table at the same time.......Cliff

[steverino]

This is part of the irony, many builders (even cam company) still believe that the smaller cam/lower compression ratio (9.0-9.5) is "safer", for street driveability, pump gas etc in the iron head 455

I do wonder if I were to call comp cams again (5-6 yrs later), and asked for advice on cam choice for this exact same build, if the xe268 would come out as their primary recommendation ?

[Steve C.]

"I do wonder if I were to call comp cams again (5-6 yrs later), and asked for advice on cam choice for this exact same build..."

Probably will depend on the cubicle the phone call is routed to. But I'll suspect they will probably regurgitate the use of the 995 valve spring !


.

[1966Lemans]

Man, this thread is really fascinating. A lot of things that the average joe would think of intuitively, are exactly the opposite.

But, what about a guy who has a street cruiser, that wants to be able to burn 87 octane? Say he has a TH350, stock converter and 2.93 rear end. If his goal is to have really good off-idle throttle response (with an occasional wheel spin), and never rev past 4500, are all these "bigger cam" recommendations still valid?

--- Jay

[72LuxuryLeMansLa.]

Originally Posted by 1966Lemans

Man, this thread is really fascinating. A lot of things that the average joe would think of intuitively, are exactly the opposite.

But, what about a guy who has a street cruiser, that wants to be able to burn 87 octane? Say he has a TH350, stock converter and 2.93 rear end. If his goal is to have really good off-idle throttle response (with an occasional wheel spin), and never rev past 4500, are all these "bigger cam" recommendations still valid?

--- Jay

I'm no expert but I would say yes. No one has to spin their car up to 6000 RPM just because it can.Use that small cam in a 455+ ci engine and near 3500-4500 RPM is exactly where it will blow up on you.

[ponchjoe]

Originally Posted by 1966Lemans

Man, this thread is really fascinating. A lot of things that the average joe would think of intuitively, are exactly the opposite.

But, what about a guy who has a street cruiser, that wants to be able to burn 87 octane? Say he has a TH350, stock converter and 2.93 rear end. If his goal is to have really good off-idle throttle response (with an occasional wheel spin), and never rev past 4500, are all these "bigger cam" recommendations still valid?

--- Jay

I've only put a few engines together but I'll bet the response you will get here is to run the 068 in a low comp 455. Search the threads, I had one started last fall/winter about a low buck 455 build.

[Matt Meaney]

Originally Posted by 1966Lemans

Man, this thread is really fascinating. A lot of things that the average joe would think of intuitively, are exactly the opposite.

But, what about a guy who has a street cruiser, that wants to be able to burn 87 octane? Say he has a TH350, stock converter and 2.93 rear end. If his goal is to have really good off-idle throttle response (with an occasional wheel spin), and never rev past 4500, are all these "bigger cam" recommendations still valid?

--- Jay

Yes.

as stated in this thread, the smaller, tighter LSA, cam with lower compression, is MORE octane sensitive. meaning, it is more likely to need a higher octane fuel to use this combo. just because the engine makes more power to a higher rpm, doesn't mean it's a dog at lower rpm. a 4.21 stroke is going to make torque, period. engine combos, like described in this thread, will work fine in front of a stock convertor and high gears. no, you won't see it's total potential at the drag strip, but it will move the car around with authority and you can incinerate the tires at will.

an often over looked and extremely important part of any cars overall drivability, (including it's running temperature) is having the carb and dist. dialed in properly.

[ponyakr]

The more I read of this thread, the more I am convinced that with 9:1 CR or more, the RA4 grind with Rhoads lifters will be VERY hard to beat with any other combination. I mean it'll idle smooth at 800rpm or lower, have plenty of vac for brakes, and make power from an idle to 5000rpm. What more could you ask of a hyd flat tappet cam, for street and mild bracket racing ?

It may not run the lowest ET, or make the most dyno hp, but I mean, ya'll go ahead and list exactly what cam & lifter combo you think is better, and why.

[Ben M.]

Originally Posted by 1966Lemans

But, what about a guy who has a street cruiser, that wants to be able to burn 87 octane? Say he has a TH350, stock converter and 2.93 rear end. If his goal is to have really good off-idle throttle response (with an occasional wheel spin), and never rev past 4500, are all these "bigger cam" recommendations still valid?

I'm actually getting real world here on this... I've got a 455 that I think needs a valve job at minimum and most likely has a bad lifter (or cam lobe) in a HEAVY wagon, 3.08 rear end, 100% street car that will never see the track and I want to run 87 octane, my AC, and power brakes. Rebuilding the original 4X-1H heads and putting another 066 cam in it seems like a waste of money and leaving potential power on the table. What do experts recommend here?

My logic for 87 octane isn't related to cost - more when you're traveling on the road 500 miles from home a bad tank of gas can really mess up your day.

[77 TRASHCAN]

Originally Posted by Ben M.

I'm actually getting real world here on this... I've got a 455 that I think needs a valve job at minimum and most likely has a bad lifter (or cam lobe) in a HEAVY wagon, 3.08 rear end, 100% street car that will never see the track and I want to run 87 octane, my AC, and power brakes. Rebuilding the original 4X-1H heads and putting another 066 cam in it seems like a waste of money and leaving potential power on the table. What do experts recommend here?

My logic for 87 octane isn't related to cost - more when you're traveling on the road 500 miles from home a bad tank of gas can really mess up your day.

I don't have a clue what size the chambers are on your 4X heads, But the 068 would be a minimalist cam choice to me for a 455.
You're not looking for the absolute power numbers, would be a great driver, not give up any low end rpm drive ability or MPG over a 066 cam, may make both better! As communicated here quite often, the awesome 068 cam can be used w/ stock springs.

[Ben M.]

Originally Posted by 77 TRASHCAN

I don't have a clue what size the chambers are on your 4X heads, But the 068 would be a minimalist cam choice to me for a 455.

Advertised as 114cc for an 8.2:1 compression ratio! Not called "soup bowls" for nothing ;-) I've done the 6X-8 + 455 build before and it was impressive. The 068 does seem like a good choice, I just hear so much flak from people on how it's "old technology." I've got a clone of it in an 8.5:1 400 with 3.55 gears and it's plenty fun to drive.