Crate Motor? What would you do?

[Victorf55]

I too am looking at getting the same atk engine for my 66. It will be a couple months before I can get all the funds together tho. If you do go with the atk I would like to know how it turns out ! Good luck on your build

[siggy_freud]

$1000 for 185 more HP is a Huge bargain. Almost what a good NO2 system would cost and that's about the cheapest power you can get.

[MadRatt]

Originally Posted by Snailed

I think you want the ATK engine. It's pretty hard to get 185 hp for only $1000. The tunnel ram Holley stuff is better suited to something that wants to rev a little too anyway. The GM crate 290hp engine is pretty tame and wont exploit the powerband of the tunnel ram intake manifold. As long as the ATK cam is not too big (under ~.65) I would go that route. You should have enough injector for around 500 hp at 43psi if you ever get more engine.

I talked to both Summit and ATK today and they were very informative. I think I'll be happiest going with the ATK motor. And the guy at ATK said with the injection I'm going to be running that motor should be over 400-425hp with real good low end torque and a nice lumpy idle.also he reassured me that with the cam profile they use that this motor will be a good reliable dd. We'll see.
The Holley Injection I got has 30lb per hour injectors good up to 600+ HP so I think that's the route to go. Thanks for all the opinions and insight. I'll keep you all posted on the results.

[Captainfab]

Ummm.....30 lb injectors are typically only good for low 400hp.

[Snailed]

Yeah that's true. 30s generally max out in the low to mid 400s at 43psi and 90% duty. You could run a little more base pressure for some headroom but it's not really the best way to do it.

How did you end up with 30lb injectors anyway? No one plans a setup to run at 90% duty right out of the box. Can you swap them out?

Also how much cam lift does that ATK have? It might be mechanically reliable but it will run like crap with a speed density EFI system if the MAP signal is choppy at idle. I would get the cam specs then call Holley and see what they say.

[siggy_freud]

Lift shouldn't be much of an issue tuning FI. It's the lobe separation that can make one hard to tune. I think you want between a 112-116 LSA for easier tunability.

[MadRatt]

Originally Posted by Captainfab

Ummm.....30 lb injectors are typically only good for low 400hp.

Yeah my bad. I said it was good up to 600hp and i meant 500hp. Been looking at to many things. Starting to get confused. Holleys web site states that there good upto 480hp.
I bought this barely used and was originally planning 300hp to 350hp. So I think I found what I'm going to buy. ATK has a 275hp 350 with 9.5:1 compression. Which is what i was originally wanting.and ATK said with the stealth ram it should be up around 300hp. Best part is its only $1800. I didn't really want to go over $2000 since this budget is getting out of hand. that leaves the $1300 difference for plenty of other things.

[Captainfab]

I would still check on the compatability of the 275hp cam with EFI.

[siggy_freud]

Post up the cam specs if you have them. I'm running one with up to .520 lift and 1.6 rockers on my tpi but it was fairly easy to tune. Has a 112 LSA which helps a lot.

[jonathan-m]

If you want to spend a little bit more on a crate engine:
http://www.chevrolet.com/performance...lsx-454-r.html

[MadRatt]

Originally Posted by jonathan-m

If you want to spend a little bit more on a crate engine:
http://www.chevrolet.com/performance...lsx-454-r.html

Ha! Almost double my whole build budget. Very cool thou

[MadRatt]

Originally Posted by Victorf55

I too am looking at getting the same atk engine for my 66. It will be a couple months before I can get all the funds together tho. If you do go with the atk I would like to know how it turns out ! Good luck on your build

Will do. I pulled the trigger today on the ATK 375hp roller motor. I will post all following info in my build thread.

Originally Posted by Captainfab

I would still check on the compatability of the 275hp cam with EFI.

This was a Good idea.

So I called Holley and ATK and this was what they said.

Holley said The 30lbs injectors would be to small for the 275hp motor. He didn't think I would be able to detune those injectors enough and that I would always be playing with it. but the 375Hp is perfect. I gave him the cam specs and he said Perfect as long as the lobe separation was between 112-114.

So I called ATK and the said they wouldn't give the lobe separation until I purchased the motor. but that he was confident that it would be what I needed.

So I said SCREW IT!!! And I purchased the ATK 375hp aluminum headed roller motor from summit this morning. No more thinking about it just done. Now maybe I can get some other things worked out since I don't have to think about this for a couple of weeks till it arrives. then

Thanx for all the input on this. It helps to air it out. Now on to the next big decision..

[Reyals Bemus]

Pretty lame how he wouldn't give you specs on the motor until AFTER you bought it... how does that make any sense?! How do you know what you're buying?

[MadRatt]

Originally Posted by Reyals Bemus

Pretty lame how he wouldn't give you specs on the motor until AFTER you bought it... how does that make any sense?! How do you know what you're buying?

yea I thought so to. But he said its a proprietary thing that makes that motor what it is. and when I told him that I couldn't buy it without knowing if it was going to work for my needs. He asked what specs I needed to be within, and I told him and he stated that without telling me exactly what it was, that it did indeed fall into the specs I needed. So I hope he's right.

[Bigdog44]

What do you guys think of going this way?

http://www.ebay.com/itm/Chevy-383-42...31044765287%26