Hey guys, I got to talking to the machinist and he asked what my plans were for my 400 block that's being converted to from a 2 bolt block to a 4 bolt with billet steel splayed caps.

I told him its for a twin-turbo 377 destroker that I am building for my little 280z. Then he asked what my target HP/TQ goals were.

I told him hopefully 500-550 RWHP or so in the end with C-16 race gas. He replied that he wasn't sure it would handle that (refering to the block).

I trust him to the point that I think, that he thinks, that he knows what he is talking about. But thinking you know and really knowing are two different things. I say that because he doesn't deal with 'race' motors alot, mostly big 1000+ cid diesels, which is why he only does block machine work for me.

Can anyone confirm or discredit this statement?

Thanks guys!!

My 010 casting (74 vintage) makes 687 HP an 660 ft lbs of torque. Main and head studs. I've had no problems. :cool:

Originally posted by marooned:
My 010 casting (74 vintage) makes 687 HP an 660 ft lbs of torque. Main and head studs. I've had no problems. :cool: How long have you been running (or miles) that motor?

Thanks.

Cable,
If it were me, I'd use a Dart Little M.
I believe you will be on the edge.
Do you plan on filling this block?
You will be generating a lot of cylinder pressure.
The problem areas will likely be the main bearing
saddles and bulkheads.I would have the main caps doweled to prevent them from walking.
I would also use someone who knows how to tune
an application like yours well as detonation or
backfires could be a problem.

DO NOT SCIMP ON THE CRANK, RODS, PISTONS, AND
WRIST PINS.

Again, I would pick the brain of someone running
a very similar assembly for components and machining tips.
Good luck.

I'll look into doweling the main caps.

As far as filling the block...to be honest I never really considered the cylinders to an issue. But I can see how they would and/or be. I was always lead to believe that filling wasn't the best idea for anything driving on the street. Although this car will not be a daily-driver, I still want to be able to drive to the strip, which is an hour away (one-way). Is filling the block still an option for me?

The crank will be a 3.50" stroke 4340 SCAT forged piece, SCAT 6.0" 4340 H-Beam rods, and JE/SRP Blower pistons. The pistons have an extra thick crown and have the rings placed lower of the piston. Compression will be about 8.0:1

I had only planned for 12 psi of boost when racing (w/race gas), and 6-8 on the street.

2 years...... bout 3000 miles

Aluminum is easier to fix and sleeves not that expensive. Talk with racers that do this sort of thing but your bottom end has got to be bullet proof or you may end up with a hunk of junk.

I have some experience with turbo Porsches only and it's been a long time. The bottom end was bullet proof even up to 2 bar but the cases split with too much boost and you had to have no detonation.

That's an interesting combination. Why two turbos? It would seem easier to run one with an adjustable waste gate or can you just use computer controlled stuff. We didn't have computers then so I'm way out of date and I'd like to know more about today's hot boosted engines.

have put 650 through a blown 010 casting

you should be fine with a 1/2 block fill.a full fill is race only.

How do I fill the block anyway? I guess I have never looked much past the ad in Summit for the stuff.

If you're spending that kind of coin on turbos and their related plumbing and headaches, why cut corners on the basis of your engine? Dart Little M is made for this kind of thing and will live waaay past what a factory casting will. I look for a factory one to crack and split thru the lifter valley. It's YOUR money, but it'll also be oil under YOUR tires if it goes. Overkill is the name of the game if you're going for that kind of power. Also gives your room to grow when this is not enough. And you know in the back of your mind that you'll eventually want more.

dont waste your time get an aftermarket block if you can afford the coin for the twin turbo,s you can afford 1800 for a dart lil m or a motown block .. hell for 3 k you can get a nice alum race block. its just my opinion but i wouldnt use a factory block for that build..it would be hard pressed for a gm bowtie block even .

The turbo's are about $1000 for the pair, the tubing part is easy. $2000 for an aftermarket block seems excessive.

Maybe I am just alittle bit confused guys. Why is it that the Turbo Ford boys get away with massive amounts of HP on their stock blocks, or how more than a few of Jody's toys (camcojb) run stock 400 blocks and make over 100HP more than my target rwhp, and live?

http://www.camcojb.com/estel/index.htm

I trust your guys judgement, so now I am just seriously considering do a decent N/A 377. I guess I might have to save the turbos for the next motor when I am rich and famous....

Ok, take this into account. The Dart blocks come fully machined with steel splayed caps. You receive it, throw your equipment in, and go. Get a quote from your machinist on what it's going to cost you to have your 400 block done up like you want, and then look back at the cost of the Dart. It's a pretty good deal, and you can rebuild it in the future.
The Mustang guys DON'T get away with running more than 400RWHP before they start having block failures. That was the point of my link. The mod motors can take considerably more.

Ideally a Dart block is the way to go. The factory one I built two years ago is a 2 bolt main 400 with studs. It's also a filled block to the bottoms of the freeze plugs or so. NO HEATING ISSUES AT ALL, I've done a 3-4 of the 400 blocks that way.It makes about 700 rwhp and we pulled it apart last year to check it and freshen it and bearing wear, cylinders, etc. looked perfect so we just put it back together.

Again, I do not recommend it for that much power either, but I think if you do the splayed caps and filled block you'll be okay with 500-550 rwhp.

Jody

Originally posted by TJC:
Ok, take this into account. The Dart blocks come fully machined with steel splayed caps. You receive it, throw your equipment in, and go. Get a quote from your machinist on what it's going to cost you to have your 400 block done up like you want, and then look back at the cost of the Dart. It's a pretty good deal, and you can rebuild it in the future.
The Mustang guys DON'T get away with running more than 400RWHP before they start having block failures. That was the point of my link. The mod motors can take considerably more. I forgot to mention that earlier, the caps are going to cost me $80 and the labor is FREE, he owes me a few favors.

Normally you'd prob be right though.

Either way, you guys have talked me out of it. The $2000 block would put my budget over the limit. I doubt I'll be going the turbo route this time.