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2300 Maggie/which engine to buid

3K views 35 replies 13 participants last post by  RACKY 427 
#1 ·
I'm going to be doing an engine build in the next few months and would like some opinions.
I have a couple of options I was thinking of but first my goal is to get 700+ whp with which ever set up I go with.
One option would be more of a budget build and the next wouldn't matter on $.

First taking my block and having it done to a 370 with all forged internals and a good set of heads along with a EMTC stage two cam. I have the stage one with rods and springs.

Second taking my block and doing a 402 stroker kit with the above stuff added.

Third buying a long block LQ9 370 or 408

I've read a lot of opinions on using a 370 or 408 for the Maggie but I am still uncertain to which one would be the best.

Also what would be a good compression for a Maggie. I know turbo and procharger like 9.0 and lower but it seems that Maggie's like the higher compresion.

And the last thing is are 317 heads good for this set up. I have a buddy that has a set built for boost which he had on a 370 ci 850 whp turbo car and has the best parts on them and wants $1,200.00 for them. Would these be a good head for any of these set ups.

Thanks for the info.
 
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#2 ·
I would go with doing a 370 CI and spinning the piss out of the 2300. Thats my plan for M122 at some point in life.
 
#4 ·
That was the other thing I forgot to mention, is wether the stock block could handle the hP or to go with an iron block.
And I don't know much about 317 heads either. So I don't know if that's a good deal or not.
 
#5 · (Edited)
Have LME build you an insane motor since you are in TX. I have an Iron 408 stroker that was built by AVAS and I put down 758/860 with my 2300. I have an IW OD balancer, 2.8 jackshaft pulley and OD cogs in rear. Oh yeah. I'm using 243s milled to 59cc with a performance valve job. I'm also using the stock throttle body. Id be over 800 easy if i have a nice set of heads.
Some other companies you could look into if you want to buy a shortblock or longblock.
AES, ERL, and LME like I said. There are plenty more reputable shops as well.
If you go Iron you should get a newer gen4 iron block like the LY6 since it has the knock sensors etc in the same place as 2005 and up GTOs. You will need to drill and tap a hole for the alt. And even then you will be only using 3/4 mounting points. That's what I had to do.
 
#6 ·
Nice build and #'s.
what compresion you have?
 
#8 ·
So I guess high compression is good for a Maggie then.
 
#10 ·
I'm also using E85.
 
#14 ·
Depends on your desired level of boost/power. You can do 11:1 if you want for 700HP, but you will likely need meth or E85 so you can keep timing reasonable. In your case, 10:1 would give you a good margin of safety.
 
#15 ·
Yea I'm thinking more of doing 9.1:1 to be safe
This is 1970 anymore where you need that low of a compression to be ok. Like myself and others have mentioned, you can definitely do up to 10:1 and be just as safe, especially on a well built and tuned motor.

If it's going to be a budget build tuned by a handheld then yeah I guess go 9:1. If you're building a quality forged engine with a good tune you can go higher.
 
#16 ·
If you are considering a high (ish) C/R motor build with F/I in mind OP? and intend on running it on pump/bowser fuel (crap), you will be very prone to engine knock due to fuel temp (TDC)....Temp and peak cylinder pressure though, will be made up with more boost, a lower C/R motor shall give you more knock resistance with equal power (it's a no brainer)... Assuming OP that this motor will be in a street driven car, knock resistance will be critical for your very expensive forged motor that i'm sure you've worked your arse off for..... Yes a higher C/R motor that is force fed can be tuned (even here in AUSSIE believe it or not) but don't forget one thing, "NOT" all fuels from the bowser are equel, not by a long shot, any reputable engine builder worth there keep, would not build you a high compression alluminum block motor, for forced induction purposes and to be run on pump fuel.
 
#19 ·
The LS7 is 11.0:1 and those things are boosted all day long making great power with little boost. Audi and BMW engines are also high compression and those also get boosted. A low compression motor is lazy as fuck when out of boost and really boring/frustrating to drive, especially with a car this heavy.
 
#24 ·
The LS7 is 11.0:1 and those things are boosted all day long making great power with little boost. Audi and BMW engines are also high compression and those also get boosted. A low compression motor is lazy as smurf when out of boost and really boring/frustrating to drive, especially with a car this heavy.
As you said... WITH LITTLE BOOST, not sure when the last time you took a genuine 750-800rwhp car for a spin was, but let me assure you, it ain't boring, frustrating nor lazy, (well not with the V7 Vortech anyway) you even so much as look at the loud peddal, and your on boost!!!
 
#25 ·
Well looks like I won't get the heads.
Looks like I've got the compresion figured out now.

So now what size motor to build. Which would be better 370 or 408
 
#27 ·
If you don't know what you want why not go to a good performance shop and have them spec what you need for your HP and $$$ goals?

No offense to anyone here, but if I was planning on building a MEGA HP setup I wouldnt be making multi-thousand dollar decisions base upon the opinions of the forum peanut gallery.

Go to a well known performance shop, explain your goals, explain your budget, then hand over your keys and let them do their job. It is their job to make all the correct decisions for you.

When you go to the Doctor for surgery do you tell him how to do his job? NO WAY!!!

Building mega HP cars is no different. Let the professionals do their thing. You will be far more happy in the long run.
 
#30 ·
My plans are for a Lq9 408, 10:1 CR, TFS 235, with the 2300 overdriven cogs, and 2.8 pulley up front.
 
#32 ·
As long as the canoe doesn't sink or blow up and everyone has a good time, it's all good.
 
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