[Dave-R (Roppa440)]

I just looked at their site and I think you may well be best off with that 2330 cam.

Anything bigger such as the 3038 or the 3945 solid will require a high compression ratio, 391 gears, and a 2800-3000 rpm stall converter (if automatic).

I would also suggest using a 750cfm carb with the 2330 cam. Any bigger cam will need an 850 I feel.

A little work in the area under the valve seats to smooth and blend that area will help too.

[Dave-R (Roppa440)]

Well your gears and headers are big enough. The headers are possibly too big to be honest. Might loose you some bottom end grunt.

If your compression is high and you have 160psi of cylinder pressure or more try the bigger cam. There might be an advantage to using 1.6:1 rockers as well to help the heads.

[Tim Ellison (Tim)]

Thanks for the advice Dave. I must admit to having doubts about the current carb for a while now.Would a 750/ 850 vac- sec be sufficient? I think the double- pumper might be overkill on my engine.

[Tim Ellison (Tim)]

Now I've stopped to think about it, Duncan Watts told me the heads had had some decent flow work done on them in the past. I can only assume the compression is more or less stock, though. I might be able to squeek by with the bigger cams, on that basis (?).

[Dave-R (Roppa440)]

If the cylinder pressure is less than 150psi though you might make more power with the smaller cam. Otherwise I would say go for it if performance is your main target.

My first choice of carb with your combo would be a 750cfm. If the heads have had work and you use the bigger cam use an 850. The double pumpers are better on the strip. The vacuum secondaries are better on the street. Your call.

[Tim Ellison (Tim)]

Thank you Dave.

Dear Santa......

[Tim Ellison (Tim)]

And Finally.....

Can I safely assume a Hughes cam comes with all the gubbins for installation? Or is it just the bumpstick?

[Dave-R (Roppa440)]

I think it is normal for springs and lifters to be extra if that is what you mean?

Things like dial indicators and degree wheels you can borrow.

[Tim Ellison (Tim)]

Hi Dave,

I was thinking more of lifter set and lube (matron). Any ideas?

[Dave-R (Roppa440)]

Lube yes. Lifters no.

You get a choice of lifter. One is stock and the other is better quality. A stock lifter has a thin wire holding it together. the better ones have a circlip.

[Tim Ellison (Tim)]

Thanks Dave.

I'm planning on going for the 3038 grind, plus a 770 double- pumper (possibly an 850), and staying with the torker 440 intake (rather than swapping to a torker II). I think I'll fork out the extra for the better quality lifters, too.

Hopefully, this will all work together ok.....

[Dave-R (Roppa440)]

Go for it man!

[Tim Ellison (Tim)]

Thanks Dave, I'll let you know how things go.

[Tim Ellison (Tim)]

From the little I know of cam swaps, it's a good idea to renew the lifters and valve springs at the same time, but is there any added value to replacing the retainers, while I'm at it? Cost would be $70- $100, plus shipping to UK.

[Dave-R (Roppa440)]

I would say at this performance level, with a hydraulic cam, that replacing the retainers was optional. If one did fail then the damage done would be very bad so most people I know would not take the risk. I personally would be in two minds about it myself. Sometimes you have to cut corners when you are on a budget. You need advice from a more experianced engine builder than me.

Anyone out there any opinions on this?

The collets I would replace for sure.

[Alex (Alex)]

If you use a spring much stronger than a Hemi rate, then I would consider replacing the retainers with something more exotic than the factory piece, if you are using mopar factory rated springs up to and including Hemi spec you should be good to go.

I don't really think the collets would need replacig either as they are driven into the stem by the force of the spring pushing up on the retainer.

I would check how much the valve stem has been hammered though, you can tell if the stem has had a beating if the valve is hard to pull out of the guide, if it is, run your finger over the collet grooves and if they feel sharp, you need to think about new valves, or at the least have them touched up to remove the sharp edge or they will dig into the guides when you try to refit them....

[Dave-R (Roppa440)]

I find I always have to clean up the grooves on mine before removing them Alex. Must be the spring pressure. These are one piece high flow stainless jobs. Single groove does not help I suppose.

[John P (Blue)]

The trouble with the stock retainers is that aftermarket performance springs come in a larger diameter than the stock ones, and consequently the new springs will overhang the retainer. I know lots of people do it this way, and I haven't heard of any failures, but personally I feel it's bad engineering practice to be using parts in an engine that don't fit as they should.

[Larry M (Larrylava)]

Hi
I need some advice on what camshaft to install in
my 70 challenger 340 4 bbl.My goal is to have a
street car that is quick off the line and also
a reasonable highway car (max 90-95mph) for short
periods..I find the setup now is quite slow from
light to light..I am also going to make the following changes..Putting in new 3:73 gears from Yukon,,adding TTI headers and complete TTI exhaust
system,,2 1/2 inch pipes with H member.I wanted to
keep the stock intake manifold,,carb (Carter AVS) and torque converter (don't know specs on this)

The previous owner told me the cam in there now was only slightly hotter than the stock cam although he got better launch speed with the stock cam and regreted changing it in the first
place..I would like to buy from Hughes engines because I heard they have the best cams for Mopars.

Please let me know your thoughts

Larry

[Dave-R (Roppa440)]

The TTI system is very good. Very expensive too!

Be aware that any cam change will require a little carb tuning (and I do not just mean idle mixture and speed). Make sure your present lack of performance is not due to this otherwise you may find that a new cam is no better or even worse!

With those gears and the headers the only limiting factors are the heads and intake manifiold.

I highly recommend the Edelbrock RPM Air Gap intake. I also suggest you smooth the 'pockets' in the heads behind the valves for better flow and get a good three angle valve job.

I assume you are sticking to a hydraulic cam?

I would use these Hughes cams HE2430AL or HE3038AL or similar. I don't know what sort of compression you have but if it is faily good then the HE3038 will work well and have a noticable idle sound. You will probably need a '2800 stall' converter with this one and vacuum for power assist may be low.

If vacuum and idle quality worry you go for the HE2430.

[Larry M (Larrylava)]

Thanks Dave

Your opinion is always great to have!..I see you
were over on this side of the ocean for New Years
Hope you had a good time..If you're ever in Canada,let me know

Larry

[Steve R (Rizrtse)]

I have a stock intake, exhaust and 670 CFM carb on my 383 with the MP purple shaft 474/280 cam. Car runs pretty well, lopes abit, good vacuum...really cant feel the power range on the high end because I feel I'm a bit over-geared with 14" 245/60R tires, 4 speed and 3:55 gears. Sounds ok but I running approximately 3500 rpms at 60 mph if the gauges are correct and they probably aren't. I get over 4,000 ral quick and am afraid I'm going to break something although the car is pulling hard. I'd love to feel 100mph. Anyway, I hear nothing but bad comments about this cam. Anyone care to comment please.

[Dave-R (Roppa440)]

Well you asked!

For that amount of duration you could have a lot more valve lift with a modern cam. That would mean more power without the car becomming less drivable. These old chrysler cams are 1960s trial and error technology that has not changed in 35 years.

[Steve R (Rizrtse)]

What do you suggest? My gearing doesnt seem to help with the mph/rpm issue. 15" wheels with some larger diameter should help. I'm on this cam being a bad selection it seems. Car still is driveable but cant get it up to 100!

[Dave-R (Roppa440)]

Steve.
There is nothing stopping you driving up to 100mph except yourself and your lack of confidence in Chrysler engineering!
If they got one thing right it was strength. Forget about what the factory tach is telling you though. Just put your foot down and listen to that lovely roar as it winds up to six grand!

The maths is simple. Your tyres are 25.6 inches in diameter. At 100mph your engine will only be doing 4660rpm with 3.55 gears. You can safely take your engine to over 5500rpm without it even starting to strain. I do over 100mph on a regular basis (120mph is about top whack) but I use 3.91 gears. My street tyres are only one inch taller than yours.

If you are really worried about what the actual rpm is try hooking up a automotive digital meter or borrow a sports tach (both hook up between the negative of the coil and chassis) and see what it says.

[Steve R (Rizrtse)]

Got it thanks. When it gets above 6 degrees I'll take it out and push it a bit! I still think an extra inch in diameter will help a bit.

[Dave-R (Roppa440)]

My wife would agree with that.

[Dave-R (Roppa440)]

OK I did the sums.

As I said. In fourth gear at 100mph with your 25.6 inch diameter tyres you should be doing 4660rpm on the engine.

If we then add an inch to the diameter of the wheels (same diameter as my 295/50/15s) so they are now 26.6 inches we get 4485rpm at 100mph.

That is only 175rpm less Steve.

"Get your motor runnin'...Head out on the Highway...."

[Hans (72challenger)]

Your always talking crap about these MP cams Dave, but what if somebody wants a solid cam without having to perform other mods to the heads because of the high lifts Hughes' solid cams have. Not to mention the valve-to-piston clearance!

I did want a hughes solid cam, but they had to much lift to fit them without requiring other mods. Maybe with a next rebuilt I will go for it, but then in combo with high CR pistons with BIG valve reliefs to accept the high lift. And mod the heads also a bit. But for this time a 528" of lift will do it with it's reasonable duration.

[Dave-R (Roppa440)]

Talking crap??

I will remember you said that when I see you!

Those KB pistons have a very generous amount of valve relef. Remember the pistons are down the bores when the valves are fully open. Or at least they should be!

Yes .528 valve lift is plenty for your little engine but how long is it at that lift??

Plus where as a Chrysler cam will give you a lot of duration to get that lift a decent modern cam (and there are a few others apart from Hughes these days) will give you the same lift with a FASTER RATE (this is much more important than just max lift) but with much smaller duration so you get good vacuum, torque, idle quality etc. All the things that make a car more fun to DRIVE on the street.