[Roy_67_SS350]

Hey All,

You may remember me posting about my engine combo not having sufficient low end torque for my needs, probably due to my cam selection. I'm running a Comp Xtreme Energy 268, Performer RPM intake, edel heads etc etc.

Anyone used the Rhodes lifters? Can I believe their advertising?

I have seen a magazine dyno test where they were showing improved low end torque av a similar engine to mine using them?

I see PAW sells them and that they're not that expensive.

I'm on a real tight budget now, and can't really afford a higher stall converter (probably need 2800 but have 2200) and a lower rear end gear (have 3.31 and probably need 3.73). Those things are off in the real distant future right now...

Just wondering if I could use the Rhodes lifters to help the power down low and if I could use them without changing my camshaft, which btw has about 3k miles on it.

[DoubleVision]

in your case, with the smallish cam, they likely will improve low end power, but I doubt they will as much as you expect, some have installed them on real big cams and couldn`t tell any difference, the lifters will tick like crazy at idle like a solid lifter cam would, which can get annoying, so instead of spending the cash on the lifters, I would just order a comp cams H268, with 218 duration, 454 lift, and a mild lopey idle without the loss of low end torque, for the price of rhoads lifters, you could order the new cam, resurface the lifters you have, and come out about the same price wise.

[Roy_67_SS350]

DV.

Thanks for the reply. If I did go with smaller cam as you suggest, would it be wise to swap my perf rpm intake with the Peformer intake that I have?

Honestly, my engine doesn't see the high side of 5500 rpm very often.

thanks,

Roy

[DoubleVision]

I`d keep the performer RPM, it doesn`t make any less low end power than the performer does, but it does provide better upper RPM breathing, even if you don`t rev it, it`s still nice to know it`s there.

[OddRodder]

On the other hand, having fond memories of my old 375h.p. 396 chevelle, I like the rhoads tick, tick, tick solid lifter sound!! I agree with D.V. though that you may not notice much difference! I have used them a number of times to gain a little vacuum for power brakes, etc.. And they do help in that instance!

[firechicken383]

I'm running a Comp Xtreme Energy 268, Performer RPM intake, edel heads etc etc.

What edelbrock heads are you running? What about compression? I don't see that cam as being to big with aftermarket heads. I would be looking at your compression or tuning.

Good luck.

[Roy_67_SS350]

Firechicken,


They are the Performer RPM heads with 64 cc chambers. The stock heads had 76 cc chambers and yielded 8.5:1 compression according to GM.

On a side note, Edelbrock informed me recently that the only difference between the Performer and Performer RPM heads was the lack of an EGR passage on the RPM heads. CHP mag shows the reg perf heads with a 166cc intake port and the RPM heads with a 170cc intake port. Neither of them are excessive for making torque and midrange power at all, at least based on everything I've read.


The Edel heads definitely raised the compression. How much? I don't know for sure. But I know that both Edelbrock and Comp Cams told me the combo would "work great" with everything else I have (2200 stall, 3.31 rear end, TH200R4 (2.74 1st gear), 26" tall tires etc.

Their idea of "working great" and my idea of "working great" must be two different things!!! LOL

This combo is waaay down on torque below 2500 rpm compared to stock. It'll barely spin the tires off the line and my 60' times are way down from the stock engine combo. (2.3 now vs. 2.05 stock) and the mph isn't much higher. Tuning the carb has helped. How much I don't know since I haven't had it back to the track since I've done most of the tuning.

Sure, a 3.73 rear gear and a 2800 stall converter would wake it up. Problem is that I don't have an extra grand laying around to do those things.

I do have an extra $100 and a Performer intake though. And I have time...

I'm leaning toward replacing the cam with something single pattern with a .050" duration at 218 degrees(instead of 224/230) that I have now) and a Performer intake. I',

BTW, the engine runs great. Starts up easily, is very liveable around town, gets good gas mileage, sounds awesome. But, I hate having to rev it like a 125cc motocrosser to make any power . My friend has a '67 Barracuda with a stock 360 and he takes me off the line. I can't pass him till I hit second gear.

He's about to add headers and intake so I gotta do something, and quick!! LOL.

Anyway thanks to everyone for responding. Here's my car.

Roy

[lluciano77]

I think it is better to mill the heads, use smaller chambers etc. to gain more compression. This does what the Rhodes lifters do. Then run an anti pump up lifter to improve top end, and you have the best of both worlds using a hydraulic lifter.

[RaggMopp]

Gee, had a '68 SS 350 myself back in the 'olden' days....

Rhoads lifters cannot change the compression ratio. What they CAN change is the effective cylinder pressure at lower RPM's.
The Rhoads is a "fast bleed down" lifter.
Just my opinion, but I would give it a try. What you're lacking is low end torque and the Rhoads should help you there by reducing the "effective" duration (@ .050") at low RPM. To what extent would depend on how they're adjusted. By that I mean that zero lash + 1/2 turn would bleed down quicker than zero + 3/4 or 1 turn. (does that make sense?) This is a lot like a solid lifter cam where you can change the power curve slightly by changing the lash.
It's certainly cheaper and easier to do than changing a cam, converter or gears. Go for it.

PS: I think Crane still makes a variable duration lifter also, but doesn't bleed down as quickly as the Rhoads.

[KeithB123]

WOW! I just wrote this same post a month or so ago! DV and Luci should remember.....do a search, you should find it.

I agree with you and hear you loud and clear. Everyone says it`s a great combo but......you must have it perfectly tuned and you must have every part of the combo.

This is your post but I must tell you what I have and maybe it`ll help you.

I have the Edelbrock RPM heads, perforemer intake. edelbrock carb 750, 373 rear end and Comp Extreme 274 ( 230/234 @.050 and .490 in and out ). and a 2400 stall. Compression ratio is about 9:7.1.

That combo stinks, the best run I had was a 14.7 ...my 305 ran a 15! I`m sure I could of tweeked it to a 14.2 but I expected low 13`s at worst.

I know what you mean as you need more torque.....my combo would never stop pulling but it just pulled slow and it pulled mostly around 4000 and up.

I had on 1.6 rockers and I went back to 1.5`s...that did help out the low end a little and I also changed the cam timing and that helped out a little. 750 carb and bigger (14 by 3 ) air cleaner also helped a little.

SOOOOOOO...this is what I`m going to do. My engine is all apart now so I`m going to mill the block to bump the compression upto about a 10 : 5 to 1, I may put on a 3000 stall OR go one cam down AND put on the Rhodes lifters. My cash is limited now also so I may go to "Your" cam and put on the rhodes lifters.

I don`t think we would have such a problem if we had roller cams...but I`m learning just like you.

If I were you I would for the time being toss on a .015 head gasket and the lifters. Both cheap. The gasket is weak but it beats a tear down...I`m gonna have it milled cuz it`s already torn down.

I`m, going to everything possible to get more torque, screw the HP...our current combos have plenty of HP but torque moves the car. I`m sure Someone on this board has had the exact same parts as you and I. Recently some one on this board mentioned the exact same thing.....was it you Double V??.....that person mentioned on something to the fact of..street cars should concentrate more on getting more torque.
!!

Let us know what you do ( especially me ) and I will definetly pass it on to what worked for me......it`s frustrating spending $1000 on those heads and have a slow car.

[anglia48]

so what's the deal with edelbrock alum heads and the XE274H cam ? you guys aren't the only ones complaining ... would the XE284H cam work better with these heads ? (9.25cr)

[firechicken383]

so what's the deal with edelbrock alum heads and the XE274H cam ? you guys aren't the only ones complaining ... would the XE284H cam work better with these heads ? (9.25cr)

Not with that Compression. Personally, I would want at least 10:1 with that.

[anglia48]

sooooo firechicken ,,,, the X274 would be ur choice with 9.25 cr & alum edelbrock heads ?

[firechicken383]

Yes, of the XE274 or XE284, I would use the 274. Personally, I would still go with more compression, unless your wanting to use the cheap grade gas. You have aluminum heads, you could run over 10.1 easy with 93 grade.

[KeithB123]

That`s what I was trying to say...more compression...along with a bigger stall....or smaller cam and Rhodes lifters. The power band is tooo high with that cam. I hear so many say that cam is small but as far as I`m concerned and have experienced that small cam needs alot of compression and stall to make a 3200 lb car move with todays standards.