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  #16 (permalink)  
Old 06-03-2013, 07:27 AM
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Quote:
Originally Posted by blowme77 View Post
Ok, I guess I'll get the msd boost timing master, I do not want to strip the engine down a second time to replace pistons!

So the accepted timing is 26 initial with 36 total (10 of mech advance) & have a boost retard of approx -2 per lb boost (I will be running about 4lbs boost retarding the timing from 36 back to 28).

At what rpm do I want to be all in? 36 advance @ 3000?

Oh and one other thing.... Recomended Spark plugs for these heads are champion RC12YC are these appropriate for a blown engine @9.7:1 scr running 4lbs boost?
Have you looked at MSD's programmable 6AL-2. It has boost retard. Build all the timing settings you want. Easy to use and change the timing in just a few minutes.

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  #17 (permalink)  
Old 06-03-2013, 07:36 AM
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The edelbrock mini roots blower I got was advertised to provide 5lbs boost on a 350 sbc & run with cr's up to 9.5:1. Thats why I bought it, I thought it would be a good match for my 9.7:1 388.

I took off my Peformer RPM & 650 carb & installed the blower & 800 carb.

The blower ran great with a quick tune, but only pushed out 3lbs boost. No signs of detonation, at this stage i was running my timing 22 initial 40 all in. There was a huge increse in power & wheel-spin.... grin factor 9/10.

The blower came with a 3.6inch top pulley & 7.5inch bottom pulley in the kit. So far the only inconvience is the top press fit pulley.

From what I understand the blower has mp122 internals.

Again..... are you sure the cam (recommended by the comp cam guys, not me) will not benifet my setup?
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Old 06-03-2013, 07:46 AM
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Cheers Fang,

Does the 6al -2 have the 20deg start retard like the digital 6 plus??
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Old 06-03-2013, 08:39 AM
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Originally Posted by blowme77 View Post
Cheers Fang,

Does the 6al -2 have the 20deg start retard like the digital 6 plus??
I don't think so, as you can design any cruve you want. I'd call MSD and ask them. I put one on my n/a 355 and like it. Had a MSD 6AL before. Here's a pick of my Drag racing timing along with the boost retard pic. Being n/a I don't run any boost retard but will when I get my blown 360 finished. You'll have to lock out the dist at 36 degrees before setting up the 6AL-2 progamable. Note: There is a 6AL-2 and a 6AL-2 programable. Also a laptop is real handy as the computer. Such as, drive to the strip, plug in laptop, change to drag cruve and have fun!
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  #20 (permalink)  
Old 06-03-2013, 09:59 AM
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Although I don't have the same set-up as you, I do highly reccomend the BTM. I pull out 2* per pound of boost. I run my timing locked out at 34*. Get the MSD Pro-billet mag pickup dist. There is another way to get the start retard without buying a new CDI. You can install a toggle switch to the ignition, as you turn the engine over and get her spinning, flip the switch.

Do you have a CDI?
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Old 06-03-2013, 10:09 AM
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Yeah, currently running a msd digital 6 plus, with billett 85551 dizzy. Looking into buying a BTM to suit.
Seems like the best way to get the start retard and boost retard.
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Old 06-03-2013, 10:30 AM
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If you are running high SCR, high boost, pump gas (like you are) def get the BTM. It's not hard to install, especially with the MSD dist. Lock out the timing, IMO
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  #23 (permalink)  
Old 06-03-2013, 11:00 AM
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What is so f *********** hard about doing this right????

buy new pistons with a big deep dish volume to drop the engine compression ratio.

8.5:1 cr OR LESS.... You need a piston with a -34cc to -36cc dish volume

That cam needs a 10" 3000+++converter and gears (3.73)
If you are not willing to to change that,,,,pick a different camshaft. Like CoMP cam #12-560-4 or #12-404-4

Or a Crane cams #113801 HMV-278-2
These are all fine with a stock 2200stall and wimpy gears.

Last edited by 68NovaSS; 06-03-2013 at 12:06 PM. Reason: Bypassing the profanity filter
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  #24 (permalink)  
Old 06-05-2013, 09:21 PM
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listen to F Bird

Until I found F Bird, I was having constant back fire problems with a 4:71 dual quad combination atop a 355 SBC. Advice: listen to F Bird !
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  #25 (permalink)  
Old 07-08-2013, 01:25 AM
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Just a bit of feedback here...

I went ahead and built this engine combo despite the warnings....

350 block 2-bolt mains, bored .060, scat stroker kit (all cast), 388ci, cast I rods, 18cc dished hyper pistons, edelbrock e-street alloy heads 64cc, comp cam hydraulic NX274h 230/244 duration @ .05, MP122 roots blower (running 5lbs boost), 800cfm eddie carb, Msd Digital 6plus ignition & billett dizzy, timing 22* initial & 32* all in, Msd BTM taking out 1* per lb boost, 2500 stall, 3.55:1 rear gears.

The 9.7:1cr & 5lbs boost on 93 PUMP gas Rocks!!! No signs of detonation, Great street manners (once it is warmed up), Great bottom end torque (thanks to the blower), Pulls hard right up to 6000rpm easy!! Biggest problem I got now is getting my 295 street radials to stick to the road!! Cant wait to take it to the track!

Very happy :-) :-) :-)
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  #26 (permalink)  
Old 07-08-2013, 06:47 AM
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new engine

Quote:
Originally Posted by 68NovaSS View Post
I run an 8.4:1, 8-71 383 on the street with a BTM and injection system. The one time I sent my BTM to El Paso for repair, bought a 6AL for the weekend test and tune, before the inj system, with fixed timing at 34*, I melted 7 pistons, an expensive lesson, I couldn't hear it detonating, but sure felt it lay down on the third run at 1,000 feet.
enjoy the engine?sounds like it should make 500 hp
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Old 07-08-2013, 08:38 AM
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I agree with fbird88.....get those pistons outta there. The first time you get over zealous with the throttle, push alittle boost, go a little lean, get some not so good gas and greedy with timing (one or all in combo) the engine will collapse the ring lands on the pistons, stick a coupla rings and that'll be the end of that. Ask one of my friends that just had to have a 6-71 on his 454 with 10.25-1 despite me telling him many times "hey, ya got it down, put some other pistons in there" Oh no they'll be fine, I'll run light boost, he says. Ok my friend, knock your self out. He listen's to me now!! He understands experience now.
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  #28 (permalink)  
Old 07-08-2013, 10:33 AM
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enjoy the engine?sounds like it should make 500 hp
Enjoy the engine? Heck yeah, lol. I suspect more than 500 with good gas, never been on a dyno. I do have two custom grind Lunati solid rollers, distinctively different characteristics, that's to be expected.
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