Less power after cam intake and carb change, what could be the problem?

[Ornamental]

I've just swapped cam, intake, and carb, but the seat of pants feeling is that there's not really a big difference. If anything, the Chally feels slower now than before. The low end power feels lower now.
Had a friend riding with me yesterday, who also commented that it felt weaker than before.

The idle is a lot rougher than before, which is kind of cool in itself, but that alone doesn't really justify spending a lot of money and time that could be better spent elsewhere.

It's a 340 with ported heads milled to achieve 10.25:1 compression.
Old set-up was a Eddy Performer intake, Eddy 650 carb, and the old cam was marked SPD22.

I googled "SPD22 cam", and found a probable good hit with some specs at http://www.mellingengine.com/Portals/5/pdf/pdf_catalog/engine-parts-camshaft-specifications.pdf





New parts:
Eddy Performer RPM Air Gap intake, Holley 750, and a MP cam P4452992. Link to cam specs.

Also changed from kickdown linkage to Lokar kickdown wire.
Kickdown works, and shifts are fine.

Any thoughts on what I can do to improve matters?

[UKcuda]

You could expect a drop in your low end power with that cam change but it should feel a lot livelier higher up.

You have changed a lot of things all at once.  It's probably not any one thing.

You really need to start working through the timing and carb set up to see what makes an improvement. 

I would start with the timing as its quicker, easier and cheaper to make changes.  Also check the colour of your spark plugs for clues to any way-out mixture settings.

Also when starting from scratch I think it helps to disconnect the secondaries until you have got the primaries working somewhere near correct.  It makes one less thing to throw you off message.

[UKcuda]

And another thought - did you mill your new intake to match the heads (if much was taken off) ?

[Ornamental]

And another thought - did you mill your new intake to match the heads (if much was taken off) ?

No, the intake wasn't milled. According to the shop that did the head job and also made the engine plan, it wasn't necessary. Having said that, it was actually a bit troublesome to install, but it turned out ok in the end.

Timing, just advance the timing little by little and take test rides until some improvement is felt?
And for the carb, first look at the plugs for any tell-tale signs of way-out mixture settings?


But, spending time to figure out the carb will have to wait until mid-july, I'm going to work for five weeks at sea again at monday, having spent most of my time off in the garage by far. I just need to get out of it.
Must admit, also at the moment I'm sick and tired of wrenching on the Chally, it's just not fun anymore, so any time consuming things will have to be done when I'm a lot less likely to put it up for sale in sheer frustration. 

[Moparal]

Did you degree the cam

[Ornamental]

Did you degree the cam

No, there wasn't a cam card in the package, so it seemed a bit pointless at the time, since I couldn't verify the measurements I would get.

[Moparal]

Shame, that could be a major reason why your down on power

[Bluemonster71RT]

   That was gonna be my question too. 

[71chally416]

Don't blame the cam grind.  That's the same one I had in my old 318 and it worked fine even with 7.9 to 1 compression. Trouble fitting the Intake? I assume you really had to pry down on it to get the bolts started. You probably have a mismatch in the worst possible place, the roof. What gears, convertor and tranny are you using? 

[femtnmax]

It's an ok cam grind if matched to the correct trany gears, axle gears, tire size, etc.  Sounds like the car is street driven.  I can't imagine many folks running 4.30 gears on the street in Norway.

[moparniac]

Port Mis alignment and not degreeing the cam .......  get that fixed! 

[71chally416]

It's an ok cam grind if matched to the correct trany gears, axle gears, tire size, etc.  Sounds like the car is street driven.  I can't imagine many folks running 4.30 gears on the street in Norway.

If you're referring to my old Cuda, it only picked up .1  second ET by switching from the original 3.55's using 28" tall slicks. Not hardly worth the trouble. But I probably wouldn't run a taller gear than that with a small block and expect "peppy" performance with ported heads and bolt on performance parts. 

If you have performance problems using that MP cam with a 10.25 compression 340 with ported heads and a AG intake, you have some other issue. It should have given you another 20-30hp putting that cam in over the one you removed. There's so many possible issues from not having full throttle because of the different height of the manifold to vertical manifold misalignment with the heads to installing the cam wrong to just a bad carb to engine timing that I hate to even speculate. Was anything else done to heads while they were off besides shaving them for compression? That could be another trouble area. If they were ported and had a VJ we can narrow your problem(s) down to about 10 possibilities with so many things changed at once.       

[Ornamental]

The heads are ported, and had a multi-angle valve job.
Valves:  Manley Stainless Steel 1 Piece Race Valves 1.88/1.60 Standard Length
Springs: Comp Cams, Good to .500 Lift
Retainers: Comp Cams Chrome Moly
Keepers:  Comp Cams 7 degree Hardened
Seals: Comp Cams High Temperature
Guides: Manganese-Bronze Alloy

Tranny is a 727
Converter is unknown.
Rear axle gears either 3.90 or 4.10. Have a 4.10 pumpkin to be installed when I get around to it.
Tire diameter is 25.85".

There were no cam card in the box the cam came in. How could I degree it then? 

About the possible port misalignment, is there another way to fix that other than getting new unmilled heads,  and tearing down the engine and putting in new pistons to keep the 10.25 compression? Or, mill the intake...?

The heads were used with the old Eddy carb and Performer intake, no problems at all with fitting the old intake to the heads at the time.

[moper]

Take a cylinder pressure reading off it Per, and post the results. If MP made the cam you probably have thier normal quality control, which sucks. If you get pressure readings that are low (and post the specs for the shortblock) you found the culprit. I'm sure it can be fixed, but it sounds like you may need that break. Going anywhere good? (not near Somalia???)

[Ornamental]

Cylinder pressure reading? You mean like a compression test using one of these:


Just trying to understand what I'm about to do, I'm supposed to take a reading of the pressure that builds up in the cylinder by cranking the engine a few strokes (with the plugs out to avoid a start).
If the pressure is low, then the valves are open for too long.

The short block is stock, at least the pistons are stock appearing.

I've measured the distance between top dead center and the deck, it's
3 mm, converted to inches, it's .0118110 inches
Piston is below deck.
Bottom dead center is 86 mm / 3.385827 inches
Cylinder bore was measured to 10.3 mm / 4.055 inches.
Checking my measures with the specs i found here:
http://www.answers.com/topic/chrysler-la-engine
it seems like my measure of cylinder bore is pretty close to stock specs.


If the cam $ucks, or rather, doesn't, then I might as well throw in the old cam for the time being?
Have the old lifters bagged and labeled, just in case of $hit happening. 
On the positive side, now that I have a clue about what to do, a cam swap will be much much faster than the first one. 

I'm going somewhere nice, Brasil. Going by Air France, which should be safest airline these days, statistically speaking. Have a friend going to a ship outside Nigeria, there's pirates there too.
I always tell him to cheer up and don't worry, because he's worth more alive than dead to the pirates.