Camshaft

[440Matt]

New to the Mopar world, looking to possibly install an improved camshaft for my stock 67 GTX 440 4spd, 3:54 gears. Id like a nice medium lope and no loss of low end power
Suggestions and combos welcome

 

[ykf7b0]

If you still have the factory heads for that 67 440 hp then they are 915 closed chamber heads. Compression should be around 9.5 to 1 and will support a decent performance cam. I recommend a Mopar Performance 272 duration, 231 @ .050, 455 lift. Cam kit is part # P4286677AE

 

[440Matt]

If you still have the factory heads for that 67 440 hp then they are 915 closed chamber heads. Compression should be around 9.5 to 1 and will support a decent performance cam. I recommend a Mopar Performance 272 duration, 231 @ .050, 455 lift. Cam kit is part # P4286677AE

Thanks for the info, much appreciated

 

[WileERobby]

Contact Hughes Engines 309-745-9558, a sponsor here, tell them you're a FBBO member.

 

[RemCharger]

Many have tried and enjoyed the mr6pak cam for this specific application.
We are trying one in my Dad's car .

 

[Geoff 2]

Would use tighter LSA, such as 108. Isky 270 Mega, 221 @ 050, & 0.465" lift.
Easy to go too big & lose low end....

 

[Challenger340]

Would use tighter LSA, such as 108. Isky 270 Mega, 221 @ 050, & 0.465" lift.
Easy to go too big & lose low end....

I wouldn't Recommend doing that until you know Headers or HP Manifolds ?
just say'in....
A tighter LSA may lose power if using factory HP Exhaust Manifolds ?

If using Headers the tighter LSA can help "scavenging"
but
if using HP Exhaust Manifolds ? then no point to the above as the Manifolds are a cork to scavenging so wider 114/115 LSA's are recommended.

 

[Geoff 2]

Chall,
This is where folks get it wrong. They use wider LSA for low end. What they should be doing is using tight LSA, but reduce duration. As per my recommendation.
D. Vizard has proved this with contract work at Crane cams where he tested 19,000+ cam combinations....& derived the 128 rule for LSA selection. The LSA tightens as cubes increase. His SBC book has a list of cams. There are 7 categories, from mild to wild. Probably #2 would suit the OP, True Street. The 050 duration for engines from 302 up to 434 are all the same: 219 @ 050. How can that be? All the same duration? The LSA is different, from 110 to 104 for the 434. That is, the overlap increases with cubes to increase breathing. Even the mildest category, Street & Tow is 104 LSA, but less duration, 207 @ 050.

 

[ykf7b0]

Don't base your big block Mopar build on what works or is suggested for a small block Chevy. There are a lot of factors that are not the same and the lifter circumference is just one.

 

[toolmanmike]

Easy to go too big & lose low end....

This ^^^^^^^^^^^^^^^^^^^^^^

 

[Wietse]

Use the engine current compression ratio and calculate the cylinder pressure by your selected camshaft specs, it will tell you a lot of how it will drive.
If you want low end power, you have to get something with decent cylinder pressure.
You will have to provide some more info to get an estimate, like your current cam specs (cam card), CR and cylinder pressure.
Tight LSA and lots of valve overlap does not do well for your vacuum and idle, lots of Mopar cams with 110-112 LSA.

 

[Curiousyellow71]

Assuming stock means manifolds I would just do a Summit 6401 and buy hylift johnson lifters. I would not use summit lifters.

 

[IQ52]

I wouldn't Recommend doing that until you know Headers or HP Manifolds ?
just say'in....
A tighter LSA may lose power if using factory HP Exhaust Manifolds ?

If using Headers the tighter LSA can help "scavenging"
but
if using HP Exhaust Manifolds ? then no point to the above as the Manifolds are a cork to scavenging so wider 114/115 LSA's are recommended.

12:26 AM? Yeah go back to bed Bob. Giving a suggestion like that........'cause I read a book/saw on YouTube that....

WAIT!.........Sorry.......

How many hundreds of engines have you built? LOL!

 

[Curiousyellow71]

Edit:
Reading up again on Dr. Vizzard, he really was a whole engine combination kind of a guy. But be careful taking some of his theories out of context...or your car will run like a tow truck.

 

[MelroseMopar]

Remember with a 4 speed some loss of low end torque is acceptable. Higher rpm and the bigger powerband is a slight tap of the clutch away, and a launch rpm is whatever you want it to be, so go with the cam that will give you the longest consistent powerband you can get with the limitations of your motor, I would recommend contacting Several of the different cam company's out there and going over what you are looking for..

Now for instance i went with a .525 231/237 on 110 cam with only roller tip rockers with a 4 speed and same gears and 28 inch tires (I am at 10.5 to 1) and have instant tire shredding capability at anything under 35-40 mph and it sounds great! Just saying that there is a huge difference in cam selection for a 4 speed versus auto car..

Do your research make some calls and let us know how it goes!
Good Luck!

 

[ykf7b0]

The thing with calling all the cam companies for advice is they can leave you confused and they base their recommendations on a Chevy grind. I recommend calling Hughes, Hensley Performance, or Mancini Racing because Mopar is all they do. Don’t negate the advice you get here from some members.

 

[Curiousyellow71]

Probably the most challenging aspect of visiting with a cam company is several don't care if it runs on pump gas.

 

[4speed68rt]

On a '67 HP with 915 heads, wouldn't the CR be around 11:1? That will make a big difference...especially on "pump gas".

 

[ykf7b0]

On a '67 HP with 915 heads, wouldn't the CR be around 11:1? That will make a big difference...especially on "pump gas".

From what I've read so far it's either 9.5 or 10.0 to 1 for a stock engine. Have you found something I haven't read?

 

[Geoff 2]

The 'tight' LSA problem. Many cam companies recommend wide LSA to save racers from themselves. Notice today how many more cams there are on 106-108 LSA compared to 25 yrs ago?? The message is sinking in.
Out of the big companies, on LSA, two 'got it' more than 50 yrs ago: Crower & Isky. There may have been some smaller companies. Most Isky street cams were on 108. Crower had a 440 street cam that was on 105. Yes 105. Mate had it in his Charger & loved it. # 206-HDP 230/244 @ 050, 105 LSA. The next size up, 205-HDP was also on 105 LSA.
The 440 had a unique 'problem' among the popular big blocks: a high R/S ratio [ long rod, short stroke ]. Great for 200 mph at Daytona, not good for street tq. That is why Mopar increased the rod length for the Hemi. A high ratio means there is less pull on the charge at lower rpms, which translated into English means using too much duration/overlap can turn it into a dog at low rpms. Cam grinder Sig Erson realised this & printed this warning in his cam catalog. NOTE: Only the BBM has this note, no other brands: ' ....with a TF transmission beware of too much duration. Although the longer duration cam will make more HP, the loss of low rpm tq will more than offset the gain at the top end & the ET will suffer'.
Sig knew his stuff, even back then: 'The camshaft with closer lobe centers will ALWAYS produce more power in the mid range than a cam using the same profile & wide lobe center, & in many application will produce more power through the range depending on many variables such as the induction system, rod angularity & flow capacity of the ports.'

Erson & Vizard worked together for a period of time.
Saying it one more time: use tight LSA & reduce duration for more low end. might mean a custom grind, but worth it.
If anyone wants copies of this info, PM me an email address.