DodgeCharger.com Forum

Mopar Garage => Engine, Transmission, Rearend, & Exhaust => Topic started by: 375instroke on October 26, 2021, 04:01:16 PM

Title: How low in RPM can you cruise with an XE274° and XE284° range cam?
Post by: 375instroke on October 26, 2021, 04:01:16 PM
Doing a 5-speed swap and want to know how low cams in this range can cruise at in a 440 or 500.  Thinking 4.10 Dana with .68 5th gear would put you at 2000RPM in 5th gear with a 275/60-15 at 60MPH.  I've never owned anything with a cam, so I have no idea.
Title: Re: How low in RPM can you cruise with an XE274° and XE284° cam?
Post by: Kern Dog on October 26, 2021, 05:38:16 PM
Come on, now....every 4 stroke engine has a cam, right?   :smilielol:

The manufacturers often show an "operating range" for their specific grinds.
I know that cubic inches plays a HUGE role in how streetable a cam acts. My 440/493 will pull in 5th gear even from 1000 rpms.....I have the MP 528 cam with 1.6 rockers, it has something like 248* @ .050. I have a Tremec 5 speed with a .64 OD 5th and a 3.55 diff.

Link to my Tremec swap thread:
http://www.dodgecharger.com/forum/index.php/topic,139198.0.html
Title: Re: How low in RPM can you cruise with an XE274° and XE284° cam?
Post by: XH29N0G on October 26, 2021, 06:11:38 PM
I think it will depend on timing and fuel mixture.  I have a cam that is not that different from those and my engine lugged before I dialed in the timing and mixture.  I don't run it low RPM like I did with smaller cam engines, but I don't think you will run into too much trouble.  I am running a 4.30 gearing and I have not pushed on it at low RPM, but I don't worry too much.  See what others say and if they have problems. 
Title: Re: How low in RPM can you cruise with an XE274° and XE284° range cam?
Post by: BSB67 on October 27, 2021, 07:40:06 PM
KD, What do you have the lash set at on the MP 528?  From memory, I think it calls for 0.028"/0.030", or something like that.

I believe the mp 528 measures 241 @ 0.050".  Due to the large lash, the MP 528 will present like a much smaller cam than the XE284 at idle and low rpm.  Plus the MP cam is ground with a 112 LSA verses a 110.

At the end of the day, I cannot answer the OPs question with any certainty.  My gut tells me that the XE284 in a 440 might be on the edge, and if it's going in a 500 in motor, maybe have it ground with a 112 LSA.  I think all other combinations would be okay. 
Title: Re: How low in RPM can you cruise with an XE274° and XE284° range cam?
Post by: Kern Dog on October 27, 2021, 08:08:16 PM
I have the lash set to their spec, I believe it is 28-32 I/E. That seems so wide though compared to newer solids. MY Lunati 316/326 ran a 20-22 lash.
I am running 1.6 ratio rocker arms though.