Sorry, another 383 cam choice question

[Q5XX29]

Also, FYI- I was incorrect  on which heads were on the 383. They are 250 castings, which are open chamber, 86 cc  castings, apparently.  So, the compression should definitely increase significantly with the closed chamber, 75 cc Edelbrock's. Do people here think that I would have any problems using 1.6 roller rockers, knowing what we now know? This Voodoo cam has .475/.491 lift with 1.5s. I know that obviously it should be test fitted to be sure.

[firefighter3931]

Well that's great news on the pistons and heads. The smaller chamber will definitely bump the static compression and wake it up ! 

As for the head gaskets I would use the Felpro 1009's which are a .040 composite head gasket. 

I'm not a fan of fast rate hydraulic cams with increased rocker ratio. The faster ramps will limit rpm due to valvetrain instability. Stick with the 1.5's or the power will fall off sooner than it should. 

I like these roller rockers from Mancini Racing ; these are a nice entry level rocker made by Harland Sharp (for Mancini) and work fine with flat tappet spring pressures. 

http://www.manciniracing.com/b15alrowibih.html



Ron

[Q5XX29]

Well that's great news on the pistons and heads. The smaller chamber will definitely bump the static compression and wake it up ! 

As for the head gaskets I would use the Felpro 1009's which are a .040 composite head gasket. 

I'm not a fan of fast rate hydraulic cams with increased rocker ratio. The faster ramps will limit rpm due to valvetrain instability. Stick with the 1.5's or the power will fall off sooner than it should. 

I like these roller rockers from Mancini Racing ; these are a nice entry level rocker made by Harland Sharp (for Mancini) and work fine with flat tappet spring pressures. 

http://www.manciniracing.com/b15alrowibih.html



Ron

Got it. Thanks. I will return the PRWs, and I will swap out the comp cams 1.5 adjustable RRs that are just sitting idle on a 440 I have (forgot I had those). Although I must say, I have Crane Gold 1.6 RRs on my '70 Charger 383 with XE274 cam, and it runs fantastic.

As far as the head gasket- the guy doing my engine work has already selected a gasket from Edelbrock that is 0.038 thick. Any concerns there? Not too late to switch to the FelPros, if there is some concern about the Edelbrock ones.

[firefighter3931]

Well that's great news on the pistons and heads. The smaller chamber will definitely bump the static compression and wake it up !  

As for the head gaskets I would use the Felpro 1009's which are a .040 composite head gasket.  

I'm not a fan of fast rate hydraulic cams with increased rocker ratio. The faster ramps will limit rpm due to valvetrain instability. Stick with the 1.5's or the power will fall off sooner than it should.  

I like these roller rockers from Mancini Racing ; these are a nice entry level rocker made by Harland Sharp (for Mancini) and work fine with flat tappet spring pressures.  

http://www.manciniracing.com/b15alrowibih.html

Ron

Got it. Thanks. I will return the PRWs, and I will swap out the comp cams 1.5 adjustable RRs that are just sitting idle on a 440 I have (forgot I had those). Although I must say, I have Crane Gold 1.6 RRs on my '70 Charger 383 with XE274 cam, and it runs fantastic.

As far as the head gasket- the guy doing my engine work has already selected a gasket from Edelbrock that is 0.038 thick. Any concerns there? Not too late to switch to the FelPros, if there is some concern about the Edelbrock ones.

Sure....the Comp 1.5's will be fine. Nice rockers !  

The XE274 is a slower grind than the Lunati so the valvetrain won't become unstable with a higher (than stock) ratio rock arm. That's the best application for the increased ratio ; slow rate of lift profiles. The Lunati doesn't really need it and the lobes are fairly aggressive anyway.  

The Edelbrock gaskets will be fine. At one time Edelbrock was repackaging FelPro head gaskets. I'm not sure if this is still the case but either way you're good to go  

This is shaping up to be a nice build ! Based on the sum of parts it wouldn't be a stretch that this engine makes 400hp/450tq at the flywheel.  


Ron

[Q5XX29]

Fantastic- much appreciated, Ron.   

[Brass]

Well that's great news on the pistons and heads. The smaller chamber will definitely bump the static compression and wake it up !  

As for the head gaskets I would use the Felpro 1009's which are a .040 composite head gasket.  

I'm not a fan of fast rate hydraulic cams with increased rocker ratio. The faster ramps will limit rpm due to valvetrain instability. Stick with the 1.5's or the power will fall off sooner than it should.  

I like these roller rockers from Mancini Racing ; these are a nice entry level rocker made by Harland Sharp (for Mancini) and work fine with flat tappet spring pressures.  

http://www.manciniracing.com/b15alrowibih.html



Ron

I'm sure the answer is more complicated than the question, but what determines whether a cam has fast ramp rates and how can you tell if a particular cam is a fast rate cam?

[BSB67]

The delta ° from advertised to 0.050" to 0.200" duration numbers

[Q5XX29]

I'm sure the answer is more complicated than the question, but what determines whether a cam has fast ramp rates and how can you tell if a particular cam is a fast rate cam?

As I understand it, one advantage that our big-block Mopars have over "the competition" is the fact that our lifter diameter is a relatively wide .904 inches (compared to, say, a small-block chevy at .842 inches). This allows more lifter surface area for the cam lobes to mash against, so a steeper ramp isn't as harsh as it would be on a smaller diameter lifter. More aggressive ramps can help make more power. Some cams that come to mind that exploit this mechanical advantage include the Hughes line, the Lunati Voodoo series, the Comp Cams Xtreme Energy, and others I'm sure. I believe that the Hughes line of cams may be the most aggressively-ramped cams of those listed above. Somebody can correct me if I am wrong here.

[Challenger340]

I'm sure the answer is more complicated than the question, but what determines whether a cam has fast ramp rates and how can you tell if a particular cam is a fast rate cam?

As I understand it, one advantage that our big-block Mopars have over "the competition" is the fact that our lifter diameter is a relatively wide .904 inches (compared to, say, a small-block chevy at .842 inches). This allows more lifter surface area for the cam lobes to mash against, so a steeper ramp isn't as harsh as it would be on a smaller diameter lifter. More aggressive ramps can help make more power. Some cams that come to mind that exploit this mechanical advantage include the Hughes line, the Lunati Voodoo series, the Comp Cams Xtreme Energy, and others I'm sure. I believe that the Hughes line of cams may be the most aggressively-ramped cams of those listed above. Somebody can correct me if I am wrong here.

Nothing "new" about the larger .904" Lifter Diameter spreading the load better(psi/area), it's been exploited since the 70's.
Just remember the faster you whack something open, and want to close it again under a "controlled" environment, the more ValveSpring pressure and rate required throughout the range, which can be tough on Lobe wear even with the extra area.
Nonetheless,
with  other factors that have changed somewhat over the years, including Oils/pressure additives, and the Lifters ability to maintain preload in 40-50 year old blocks with sloppier worn Lifter Bores, the faster .904" ramps can be problematic.
IMO,
stay clear of Lobes wanting 150 Lb plus seat pressures and 330+ Lb over the nose loads....... even WITH the .904" Lifter

just say'in...
.904" specific lobes can still work, but as a standalone "panacea" to performance by themselves ?, gains can be slim to none versus std easier Cam ramps and other imput data(KNOWN Head Flow, Port Balance, etc.).... or even just applying 1.6 Rockers instead of 1.5's to mushier ramps that are still stable just over 300 lbs over the nose even with 1.6's?

Case in point....
this is a mushy .842" Lifter $129. Cam Grind with 1.6's.... 120 Lb seat and 315 Lbs over the nose(safe), works just fine !
http://www.dodgecharger.com/forum/index.php/topic,123378.0.html

[Q5XX29]

Okay, another update and quick question (I am currently holding up my engine guy with this decision):

He has the new Performer RPM heads on, and said that 3 MORE OF THOSE damn Johnson lifters aren't rotating in the lifter bores, so he is nervous that the initial maladies with the first problems (bad lifter, crappy new valve springs) has either worn the cam lobes somehow, or the Johnson lifters are just the worlds worst lifters, or both.

So, he (and I) is really wanting to button the engine up and be done, and he DOES have on hand a brand new Edelbrock Performer RPM cam and lifter set (7194) that he can install, since he is nervous about my brand-new-but-possibly-damaged Lunati Voodoo 268/276 cam. Normally, I wouldn't choose an Edelbrock cam, but since I now DO have 9.6:1 static compression with the Edelbrock heads, and the RPM intake manifold, I think I will have him put it in. Then, I don't have to wait ANOTHER week for a different cam to arrive. Edelbrock claims 421 hp on a 383 with their RPM Total Power Package, which is exactly what I will have now. That sounds pretty nice.

Any objections/discussion from the crowd?

Thanks again in advance.

[cdr]

it will work ,but it will come one later & idle rougher .

[Q5XX29]

Never mind... Spoke with Ron, and due to concerns about over-camming the 383 and low vacuum for the brakes with the Edelbrock cam, decided to keep in the Lunati Voodoo 262/268, and just try a new matched set of lifters.

[BSB67]

The stories that I hear about today's hydraulic lifter is sickening.  I think us old car performance enthusiasts will need to accept the reality that a quality hydraulic flat tappets have gone the way of the Dodo bird.  If someone decides to make a quality hyd lifter, they will probably cost $800 a set.

I know this project has gone way sideways on you in cost, scope and schedule, but you might consider a small solid lifter cam with nitrided lobes, and a high end tool steel lifters.  This is what I will do for any FT cams that I do going forward.  

[firefighter3931]

The stories that I hear about today's hydraulic lifter is sickening.  I think us old car performance enthusiasts will need to accept the reality that a quality hydraulic flat tappets have gone the way of the Dodo bird.  If someone decides to make a quality hyd lifter, they will probably cost $800 a set.

I know this project has gone way sideways on you in cost, scope and schedule, but you might consider a small solid lifter cam with nitrided lobes, and a high end tool steel lifters.  This is what I will do for any FT cams that I do going forward.  

I have to agree....the problems Clint is having with these hyd lifters is very disappointing ! 

This is the first time I've read about issues with the Johnson lifters....from all reports they are supposed to be the best available. Maybe just a bad batch ? 

I'm a big solid lifter fan as well. Any flat tappet cam that I'd consider running would be a solid lifter with nitriding and an EDM lifter with priority cam lobe lubrication. 


Hopefully the new hyd lifters work out well for this build but if not....it's solid cam time ! 




Ron

[Q5XX29]

I can see the wisdom of your advice, and next time around will be sure to give serious consideration to a solid lifter cam.

I don't mind the actual expense of the defective components as much as the principle of the whole thing. I am already frustrated thinking about how the lifter company (Johnson/HyLift) and the spring manufacturer (Lunati) will probably try to weasel their way out of refunding my money. And then there is the time consideration. Trying to get this car back together for my son before he leaves on his band trip and then his exchange program trip to Germany, or he will be without his car for another three months.

[Q5XX29]

Well, this is certainly looking encouraging:

[cdr]

The stories that I hear about today's hydraulic lifter is sickening.  I think us old car performance enthusiasts will need to accept the reality that a quality hydraulic flat tappets have gone the way of the Dodo bird.  If someone decides to make a quality hyd lifter, they will probably cost $800 a set.

I know this project has gone way sideways on you in cost, scope and schedule, but you might consider a small solid lifter cam with nitrided lobes, and a high end tool steel lifters.  This is what I will do for any FT cams that I do going forward.  

I went small solid FT cam with Trend tool steel lifters with EDM oiling, so far all is good.

[firefighter3931]

Well, this is certainly looking encouraging:

Looks good....165psi cold is great. With the engine warmed up to temp it would be higher....maybe another 10 psi or so.    With the Edelbrock cam it would have been below 150 cranking so keeping the VooDoo stick was the right choice. 

Make sure the lifters are run in for 20 minutes at 2000 rpm. It doesn't hurt to blip the throttle every now and then to promote lifter rotation. 

Anxious to hear this badboy run. Your son is in for a pleasant surprise when he drops the hammer 


Ron

[Q5XX29]

Finally got the car back, everything together and running. First time with gas pedal down halfway, horrible pinging! I thought I would have to dial back the timing, but then the engine guy told me that the car was out of gas and all he had was some 87 octane so he had dumped some of that in. Soooo, quick trip to the gas station do fill up on 91 premium (the best we have out here at the pump, unfortunately), and still just a touch of pinging so I dumped in a few gallons of Sunoco 110 that I keep around for my 427 cobra. Voila- ping all gone now. Ready to hammer down...

WAY more power! Finally this 383 runs like it should. Might even give my '70 383 Charger a run for the money, and that is a high 12 second car. Pulls very hard, idle through 5600, is all I've had it to so far.

So, this concludes this chapter of my son's 383 project car. Although I might have to swap in the 4.56s I have laying around for a bit of fun next weekend.

My sincere thanks for the collective wisdom and interest on the forum here. Especially Ron, who was kind enough to call me on a weekend to advise me on a couple of issues. 

[garner7555]

Good to hear!   Great forum, great people, with great advice.           

P.S. -  We wouldn't mind seeing a video of what this car runs like now.   

[firefighter3931]

WAY more power! Finally this 383 runs like it should. Might even give my '70 383 Charger a run for the money, and that is a high 12 second car. Pulls very hard, idle through 5600, is all I've had it to so far.

Most excellent ! 

Sure glad we touched base before the "other" cam was installed. The outcome would have been nowhere near as good. 

As mentioned above ; we need a vid clip ! 



Ron

[Challenger340]

Ron can make 'em RUN... no doubt about that !   We're all very lucky he hangs here !

Thanks for sharing

VIDEO !

[Q5XX29]

I will try to get a video up sometime soon. Plagued with oil leak issues now. Changed oil pan gasket, that is now staying dry, but see some seepage from the timing chain cover now. Arghhh.

[Q5XX29]

I still need to take a video of the car accelerating, but I did take this clip the other day:

[firefighter3931]

That sounds nice and healthy @ idle !   

How is it running ? Have you beat on it yet ? New converter in yet ?



Ron