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Author Topic: What about roller lifters and 1.6 ratio roller rockers for 318 build?  (Read 2698 times)

Offline cudaracer

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After being disappointed in my top end 318 rebuild for the 72 cuda, I am preparing for another go at it.

So far in the stage I build,
Stock bottom end with low CR went lower with 360 308 swirl heads, chamber vol = 68cc
Mild porting and gasket matched
Weiand dual plane
Holley 600
0.477 / 0.480 lift with 268 / 280 durations (I / E) Comp cam
Dakota 360 exh manifolds, dual stainless with Pypes mufflers
3.23 rear
904 automatic with shift kit and stock torque converter (anybody know stock rpm value?)

And this setup is just not getting it with me.
I am seeing cyl pressures in the 120 psi range, turned with starter motor.

So,
Here are my options for stage II, budget limited of course.

A.    Cambell Industries 392 stroker setup is only $1345, and with a bottom end reman, I am looking at just under $2K.
B.    Bottom end redo plus 10:1 forged plus 1.6 Hughes billet roller rockers plus roller lifters, should come in about the same price.

Just looking for opinions/experiences.  I want to keep numbers matching 318 block, FYI.
Option A will be more about torque, where option B can be more of a high rpm screamer.



Thanks all.

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Offline Chryco Psycho

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Re: What about roller lifters and 1.6 ratio roller rockers for 318 build?
« Reply #1 on: October 31, 2012 - 08:54:51 AM »
Torque rules , I would go to the stroker

Offline HP2

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Re: What about roller lifters and 1.6 ratio roller rockers for 318 build?
« Reply #2 on: October 31, 2012 - 09:44:18 AM »
You need to build cylinder pressure to make power. With that head combo, your cam is too big. With a $2k budget, I asssume you looking for a fairly low dollar approach?

If you don't want to get far into the engine, and keep an ultra low buck approach, I'd suggest a cam swap to a much smaller duration cam. Something down around 210-220 duration and installed 4* advanced to help build pressure. Figure you could do this for a couple hundred bucks and a weekend worth of work. IMO, I wouldn't bother with roller lifters or rockers unless you're turning high rpm, and you don't need rpm for torque. BTW, to run roller lifters, you need a roller cam which means this budget will expand greatly as you get into all the roller work. Benefits for the cost on a stock style street engine are limited.

If you want to get into the engine, a piston swap to a taller compression height will also bump up cylinder pressure. A KB167 should get you close to zero deck height which would really bump up your squeeze. The compression height on these is 1.81 compared to the 1.74 of a stock piston. Figure this is around $500 with pistons, new rings, and a hone job. Of course if your this far, you may want new bearings as well so add another $100 for that.

Stroker kits will get you more cylinder pressure as well, but don't expect huge jumps in power with them as keeping your stock head and exhaust combo will limit potential power these would produce. For a couple grand in stroker work, leaving everything else the same, I'd guess you may only see 20-30 more horses over a simple piston change. However, it will probably produce more torque down low, which is what really makes these cars fun to drive.

I don't see you option B as a substanially higher end screamer over Option A because too many key components are not changing. The roller components don't add rpm, they just reduce friction. With stock heads, mild porting, and stock manifolds, rpm over 5000 is just adding stress to the engine without power gains.

BTW, you stock convertor stall is probably around 1400 rpm or so, give or take a couple hundred.


Offline cudaracer

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Re: What about roller lifters and 1.6 ratio roller rockers for 318 build?
« Reply #3 on: October 31, 2012 - 10:39:54 AM »
Thank you HP2, I hope you don't mind a few follow up questions.

I have heard that my cam is my main problem before, and recently dug up a hughesengine cam called the 518 whiplash cam, perfect for low CR engines.  What do you think of this cam?

Link to cam:

http://www.hughesengines.com/Index/products.php?browse=category&level0=U21hbGwgQmxvY2snTEEnIDI3MywzMTgsMzQwIGFuZCAzNjAgZW5naW5lcw==&level1=Q2Ftc2hhZnQ=&level2=RmxhdCBUYXBwZXQsIEh5ZHJhdWxpYw==&level3=TXVzY2xlIENhcg==&partid=25113


Also, where do I want to be with my setup for a new torque converter?  2500rpm? 
And what if I do stroke it, would that cam not be optimal and what about the converter with that stroker?

Budget is always an issue, but I got to say, so is my time.  That is why I am now asking, as I don't want to have to repeat this stuff.

thanks

Offline Chryco Psycho

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Re: What about roller lifters and 1.6 ratio roller rockers for 318 build?
« Reply #4 on: October 31, 2012 - 11:20:04 PM »
the Whiplash cams are the right idea but hughes is miserable to deal with
Lunati has a the VooDoo series 60402 should do what you want but you have to math=ch everything so it all works at the same rpm so cam , converter , intake all need to work together + buiding good cylinder pressure & making the heads flow .
 a low stall converter will work well with a smaller cam that will build cylinder pressure 2500 make be a waste of powrband

Offline cudaracer

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Re: What about roller lifters and 1.6 ratio roller rockers for 318 build?
« Reply #5 on: November 01, 2012 - 06:40:27 AM »
Thanks to all for responding.

I guess I am a bit frustrated, as there appears to be no simple formula for me. I came here expexting to find several simple teen SB build recipe combination that includes my 904 auto, but I don't see any, and nearly all are for automatics. 

And I agree, Hughes is difficult to deal with.  When I mentioned my setup, there attitude was basically, wtf were you thinking?  I mentioned roller lifters, which they sell, and he claims they don't offer any performance benefit.  I doubt that.  I purchased my comp cams cam after spending months using their camquest program, dialing it in as best I could and using their best fit guides as a general rule, but it turns out I am way off. 

Why is this such black magic?  Little has changed in 40 years for this LA class motor, so you would think there there are clearly specified stages of build for every 75 hp or so you want to climb? 

I am just not finding it.

Offline Chryco Psycho

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Re: What about roller lifters and 1.6 ratio roller rockers for 318 build?
« Reply #6 on: November 01, 2012 - 07:58:16 AM »
Comps cam are basically designed by chevy guys for a small block with a short rod ratio , completely different from a long rod Mopar engine .
 Hughes is his own worst enemy too .
 Sorry we do not have a list of engine builds / combos .
the 318 is difficult to upgrade , adding a 4 bbl intake & carb basically gets you nowhere .
 I have built a few 318s with success , increased compression , good cam & porting the heads helps .
 the 302 swirl castings are great too , or you can up grade the whole top end to the large port 360 / 308 swirl castings & larger intake but you have to be careful with compression using bigger heads . it is not magic just a careful selection of matching parts , the stroker is a big help as it will move more air & will make use of larger port heads & will increase torque which the 318 lacks .

Offline HP2

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Re: What about roller lifters and 1.6 ratio roller rockers for 318 build?
« Reply #7 on: November 01, 2012 - 09:38:42 AM »
I have no first hand experience with Hughes cams, although I will this winter as I have one going in to my 360. Hughes  does have a lot of good mopar experience. I've never had any trouble dealing with them, but I've always know exactly what I need and never hit them up for advice. I've seen plenty of other complaints about them though. I won't say they are wrong about the roller lifters, but they aren't far off either. The performance benefit to them and roller rockers in a mild street build is very negligible. Keep in mind the factory did it for emissions and mileage benefits. Adding these items to an engine may increase its efficiency .1%, so for you the gain is practically nothing. For the factory that has to meet mileage and emissions specs as a corporation, a .1% gain over a million engines is a huge gain. Similarly, at high rpm or maximum output, they show greater percentage of gains over stock. Ultimately, power is about efficiency and adding these parts will net an improvement, but the gain for the cost in what your doing will be low and you can gain more effcicieny in other areas for less money. Like them or not, the fact is emmission requirements are what have driven the new engine designs and their improved levels of efficiency.

I've never used Comps calculators. I used to have a Desktop Dyno program but lost it when I upgraded my system because new computers don't operate of DOS like the older ones, so my program was incompatible. What I have noticed about using it, is that you have to be very careful about the inputs as they can create some overly optimistic results. If you are unfamiliar with engine builds and strictly go by the programs, they can lead you down some less than satisfactory paths. They also don't tend to have a big red marker saying that cylinder pressure is a key goal to achieve. It is usually buried in some data points somewhere so it is not easy to understand the impacts change may have on the squeeze. Most calculators tend to put optimal horsepower first and foremost. I'll admit high HP numbers are sexy, but ultimately power is all about torque and the more torque you have across a broader range, the better the engine will perform and the higher the power numbers rise.

Despite their huge production volume, 318s have never been a "go to" set up for performance. So build info on them is definetly lacking and the first response from most people is to dump it for a 360.  Since you want to keep it, I guess I have a few questions for you. The two biggest of whats the goal and what the budget? Budget can include time as you mentioned earlier.  Goal, obviously more power, but if it is simply the desire to burn rubber, you may not want to mess with the engine at all, or at least get it back to a previous power level. I ask because if that is important, changing the engine may be a waste of effort compared to putting in a higher rear end gear and an overdrive transmission.  Same with the torque converter. It will hit the tires harder to make them spin, but stall is created by removing efficiency and the higher stall may leave you even more disappointed. Similarly, stall is created by torque, so a low torque engine with a high stall may be a bigger pig tham a regular stall converter with a high torque engine.

Like CP said, it is putting together a good combo. It sounds like you have good heads, and you cam isn't awful with the right cylinder pressure, so now you need to match up the rest of the combo. You definetly need help in the compression department. The 390 kit will produce increases in moving air and put more squeez on the air you take in. I guess you will need to decide if you want to spend the rebuild money and time to go there. Even if you keep the stock crank and rods and only replace pistons, you are still looking at a tear down and machine work. IMO, a 390 with the 360 heads and your cam should be a decent increase in power.



 

Offline cudaracer

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Re: What about roller lifters and 1.6 ratio roller rockers for 318 build?
« Reply #8 on: November 06, 2012 - 10:18:37 PM »
OK, I think I have made up my mind.

More cubic inches.

392 is my target, stroked and bored.
Combined with my 360 heads and medium cam, I should have quite the setup.

Anyone out there use cambell enterprise strokers???

http://www.campbellenterprises.com/318-stroker-kit-mopar-318-5.2-stroker-kits.php

Offline PlumCraZRT

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Re: What about roller lifters and 1.6 ratio roller rockers for 318 build?
« Reply #9 on: November 07, 2012 - 02:51:38 PM »
OK, I think I have made up my mind.

More cubic inches.

392 is my target, stroked and bored.
Combined with my 360 heads and medium cam, I should have quite the setup.

Anyone out there use cambell enterprise strokers???

http://www.campbellenterprises.com/318-stroker-kit-mopar-318-5.2-stroker-kits.php


It's worth while to sit down and calculate some basic cylinder dimensions.  You can determine what compression ratio you will end up with (and tailor it with different head gaskets if needed) in addition to dialing in your quench (if the heads are closed chambed).  Don't just throw your money at commonly used numbers like head flow and displacement.  These things mean little without proper compression and proper valve lift and duration.
mmmmm.... Mopar.... *drool*

Offline cudaracer

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Re: What about roller lifters and 1.6 ratio roller rockers for 318 build?
« Reply #10 on: November 08, 2012 - 06:11:48 AM »
Thanks, I am well aware of how to get the CR I need, but I was just unaware of how much it would affect me, when I did a top end rebuild with less than 8:1.
It seems to make a lot of difference in a small block.

Offline HP2

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Re: What about roller lifters and 1.6 ratio roller rockers for 318 build?
« Reply #11 on: November 08, 2012 - 09:18:39 AM »
Compression makes, IMO, the biggest impact on power. Aside from the static ratio you calculate with swept voulme and head cc, there is also the dynamic ratio that is the combination of static values, cam timing, valve events, and altitude.

Here is a calculator I use to see where all those figures put you in a running state " http://www.rbracing-rsr.com/comprAdvHD.htm

Because of my altitude, I can often build engines with 11:1 static compression ratios combined with moderate cams and keep things out of detonation.  By contrast, as in your case, you can take a moderate compression engine and bleed off too much cylinder pressure with too large a cam.
« Last Edit: November 08, 2012 - 09:23:25 AM by HP2 »

Offline cudaracer

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Re: What about roller lifters and 1.6 ratio roller rockers for 318 build?
« Reply #12 on: February 18, 2013 - 12:27:35 PM »
Great discussions and learned so much so fast.

One more question.
I found a 1995 360 short block, complete.  Aside from a new motor mount and flex plate and oil pan, what else do I need to modify to fit into a 72 e-body with 1976 360 heads (non- roller).

Thanks.

Offline barracuda7199

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Re: What about roller lifters and 1.6 ratio roller rockers for 318 build?
« Reply #13 on: February 20, 2013 - 09:15:17 AM »
the 76 360 heads will not work on the 95 magnum 360. a magnum motor oils thru the pushrods like a chevy the 76 oils thru a passage in the block and head itself then thru the rocker shaft. you could take the magnum 360 combined with enginequest replacement magnum heads and have a strong running engine! there is a kit out to allow you to run chevy roller rockers on the magnum heads which would give you a valvetrain that is adjustable. the enginequest heads are a good deal and flow a ton of air as well as fixing the stock magnums bad habit of cracking between the valves.
Brandon

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Offline PlumCraZRT

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Re: What about roller lifters and 1.6 ratio roller rockers for 318 build?
« Reply #14 on: February 20, 2013 - 05:08:02 PM »
I just read your first post again and realized that everyone thinks you have too much cam...

The best number to list when talking about cams is duration at .050".  You listed:
0.477 / 0.480 lift with 268 / 280 durations (I / E) Comp cam

I'm guessing you listed the advertised duration, which probably puts your .050" duration right around 210.  I think you will be happy with that duration, but there isn't a whole lot of lift on the cam.  I would think you would be able to get over .500 lift with a Lunati or Hughes off-the-shelf or a custom cam (not much more expensive).

If you need a compression calculator, send me a PM and I can email you an excel spreadsheet I made up to calculate it.
mmmmm.... Mopar.... *drool*

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Re: What about roller lifters and 1.6 ratio roller rockers for 318 build?
« Reply #14 on: February 20, 2013 - 05:08:02 PM »