408 Stroker with Power brakes?

Posted By: cudabitten

408 Stroker with Power brakes? - 03/23/12 04:57 AM

Considering the 408 stroker for my project, but again looks like it is not power brake friendly. Anyone know for sure?
474 Intake / .474 Exhaust & 238 Intake / 238 Exhaust duration @ .050 - 110 degree lobe separation

Thanks.

Posted By: 471Magnum

Re: 408 Stroker with Power brakes? - 03/23/12 12:33 PM

That shouldn't be a problem, but you're approaching the limit.

Posted By: 540challenger

Re: 408 Stroker with Power brakes? - 03/23/12 12:45 PM

Quote:

Considering the 408 stroker for my project, but again looks like it is not power brake friendly. Anyone know for sure?
474 Intake / .474 Exhaust & 238 Intake / 238 Exhaust duration @ .050 - 110 degree lobe separation

Thanks.

Look like the cam in my blue printed crate 408. It is fine if it is the same engine i pull over 17 inchs of vac at idle.

On another note if it is the blue printe engine don't do it. I had to spend over 1400.00 bucks just to fix the pos. PM if you need more details

Posted By: Streetwize

Re: 408 Stroker with Power brakes? - 03/23/12 03:07 PM

What compression and intake? It's not only the cam that effects idle vacuum.

Posted By: 471Magnum

Re: 408 Stroker with Power brakes? - 03/23/12 05:43 PM

Good point. I was kind of blindly assuming a 10:1-ish motor.

Ignition advance makes a difference as well.

Posted By: Hotlumpy

Re: 408 Stroker with Power brakes? - 03/23/12 08:00 PM

I have a 408 stroker in my 68 Barracuda with the following: 10:6:1 comp. Edelbrock heads, Air Gap, Holley 750, Hughes cam with 243 248 @ .50, .540-.550 lift. I am running power breaks and only pulling 9 inches of vacuum at idle, I kind of figured out a loophole by accident, I am running non-power disc break calipers off of a 71 or so Junkyard dart with my power system and it works quite well. Anyone else ever try this?

Posted By: autoxcuda

Re: 408 Stroker with Power brakes? - 03/23/12 08:13 PM

Quote:

I have a 408 stroker in my 68 Barracuda with the following: 10:6:1 comp. Edelbrock heads, Air Gap, Holley 750, Hughes cam with 243 248 @ .50, .540-.550 lift. I am running power breaks and only pulling 9 inches of vacuum at idle, I kind of figured out a loophole by accident, I am running non-power disc break calipers off of a 71 or so Junkyard dart with my power system and it works quite well. Anyone else ever try this?

71 four piston calipers are the same whether power or non power. It's the master clylinder bore that changes power vs. manual in those years' A-bodies (66-72)

Posted By: autoxcuda

Re: 408 Stroker with Power brakes? - 03/23/12 08:14 PM

Quote:

Considering the 408 stroker for my project, but again looks like it is not power brake friendly. Anyone know for sure?
474 Intake / .474 Exhaust & 238 Intake / 238 Exhaust duration @ .050 - 110 degree lobe separation

Thanks.

Sounds like a Comp XE274 hyd cam???

Posted By: 471Magnum

Re: 408 Stroker with Power brakes? - 03/23/12 08:59 PM

Quote:

Sounds like a Comp XE274 hyd cam???

No. That's not the XE274H. I had that one in my 410... before it lost a lobe. But it is what I based my comment on. No hint of low vacuum in my combination. It's well into the teens. I run about 18 degrees of initial advance with a dual plan and 10:1 CR.

Posted By: loco340cuda

Re: 408 Stroker with Power brakes? - 03/24/12 01:34 AM

I have a 70 Cuda with a 417 stroker and factory power brakes (disk front, rear drum). The motor is 9.5:1 compression with a MP 484 cam (241/241, .484/.484 lift). I pulls about 14-15" of vacuum and the brakes work fine.

Posted By: cudabitten

Re: 408 Stroker with Power brakes? - 03/24/12 01:44 AM

I'm not sure what cam it is. It is a BluePrint Engine, and I will probably not go with it after all. Looks like some board members here have had issues with this engine from BluePrint.
When I called them up to ask about the vacuum specification, they did not sound like they knew what they talking about. That why I figured I would ask you Guys.
Thank you for your responses.

I guess the price was too good to be true.

Thanks,
Chris.

Posted By: loco340cuda

Re: 408 Stroker with Power brakes? - 03/24/12 03:07 AM

Forgot to mention, the specs on the cam you mentioned in your original post sound like it is the MP 474, the cam one size down from mine.

Posted By: 383man

Re: 408 Stroker with Power brakes? - 03/24/12 04:34 AM

Some will surprise you. My old 440 had the MP .557 cam with 10.0 comp and 906 heads and the power brakes worked fine. My new 493 has a solid flat tappet with 264 & 270 at .050 with .591 lift (.630 with my 1.6 rockers) with a 110 LSA and I have it in on a 106 ICL. The power brakes still work but if I stay on the pedal too long I can feel it starting to get harder. I am thinking about a vacum pump but 99% of the time on normal driving they feel normal. Its only when on the pedal long like a beltway ramp or if I let up and hit the pedal again right away. But I was surprised how good they work with this cam in my 493. Ron