Engine swap ... brakes worthless

[Long4door]

So I swapped a 360 I place of my 318 this included a mp 284 484 and now my brakes are not . So I ordered a canister and wow so much pedal but my brakes are not please help

 

[74gtx]

if I understand correctly you have a larger cam now and your vacuum is low?? This would make the pedal stiff if that’s the case. Sorry. It’s kinda hard to tell what your saying.

 

[Big Bad Dad]

if I understand correctly you have a larger cam now and your vacuum is low?? This would make the pedal stiff if that’s the case. Sorry. It’s kinda hard to tell what your saying.

Doesn't everybody immediately know exactly what mp 284 484 means?? It makes your brakes not.... C'mon man!

 

[ckessel]

I forgot to wear my ESP hat.

 

[PurpleBeeper]

Because of your cam, your engine vacuum is low. The engine vacuum is what gives your power brakes "power", but you don't have much vacuum anymore. You can add a vacuum reservoir canister or a vacuum pump.

 

[Bighouse]

Brakes are for quitters.

 

[Kern Dog]

if I understand correctly you have a larger cam now and your vacuum is low?? This would make the pedal stiff if that’s the case. Sorry. It’s kinda hard to tell what your saying.

Yeah....you're not charged by the word here. If you want help, you'll need to be more clear.

 

[Long4door]

Because of your cam, your engine vacuum is low. The engine vacuum is what gives your power brakes "power", but you don't have much vacuum anymore. You can add a vacuum reservoir canister or a vacuum pump.

Yeah the cam killed my vacuum so I did add the canister it gave me a huge improvement in pedal feel but sadly it still takes almost 10 ft to stop and i just don't get how my brakes are not functioning, it did take a month to do the swap

 

[Long4door]

Doesn't everybody immediately know exactly what mp 284 484 means?? It makes your brakes not.... C'mon man!

I dont know how to explain or google my situation because I have a great brake pedal feel especially after adding the vacuum canister to my power brakes but my brakes are not working . Mopar purple cam 284 484 is what came in the short block i bought I know there are more conventional grinds available but it's what I have . So any thoughts or questions please share and I'll respond with the info

 

[Geoff 2]

Vacuum canisters do not add vacuum, they just give more 'reserve' so that you get more than one pump of the pedal before you run out of brakes.
If this is a low compression engine, then I can understand poor/no brakes with the 284 cam in a 360. Will not be much better with a high comp 360.

 

[Long4door]

Vacuum canisters do not add vacuum, they just give more 'reserve' so that you get more than one pump of the pedal before you run out of brakes.
If this is a low compression engine, then I can understand poor/no brakes with the 284 cam in a 360. Will not be much better with a high comp 360.

My vacuum at idle is 7 one blib of throttle and it's 15 to 20 . I am curious if I can adjust carb to improve this ? My compression is 9.3 to 1

 

[Kern Dog]

7" is waaaaay too low. There are no adjustments to anything that will restore idle vacuum to 18-20" for proper operation of the vacuum booster. You would be far better off either using a manual master cylinder or installing a vacuum pump.

I did. Start reading at #767.

Re-Rebuilding the 440-493 in a 1970 Charger

 

[Long4door]

Ok , thank you I will be considering this

 

[slepr1]

I've used that same cam before and also the 509 cam. Now I have an even bigger cam. No brake issues ever. No pump, no can, nothing changed or added. Maybe still some air in you brake lines?

 

[dadsbee]

You could have a GREAT pedal if all your wheel cylinders where seized!!

 

[Long4door]

I've used that same cam before and also the 509 cam. Now I have an even bigger cam. No brake issues ever. No pump, no can, nothing changed or added. Maybe still some air in you brake lines

What kind of vacuum were you pulling , I'm going to get a hand bleeding them, using my vacuum bleeder yesterday was alot more awkward then I remembered on the fronts . If it's not air in the lines I'm thinking maybe a leak around the carb or spacer because I'm getting 7 at idle with my idle screws about 3 .5 turns out best I could get it.

 

[Long4door]

You could have a GREAT pedal if all your wheel cylinders where seized!!

Could be ! Already a yr old lol

 

[Kern Dog]

I've used that same cam before and also the 509 cam. Now I have an even bigger cam. No brake issues ever. No pump, no can, nothing changed or added. Maybe still some air in you brake lines?

No offense but I call bullshit on that IF you have a vacuum booster.
I ran a '509 and that cam did not produce enough vacuum to adequately support the power brakes.

 

[Don Frelier]

You may have a vacuum leak.
3-1/2 turns is quite a bit.
I have a .484" in a 383 and it's close to 1-3/4.
Power brakes work well.

 

[moparmarks]

I have a simular cam, 282/480 in my 360 and I have real good power brakes. I think you have something else going on such as a weak booster or vacuum leak.