[updated:LAST EDITED ON 15-Mar-02 AT 11:36 AM (EST)]OK here goes. What do you guys think of this configuration? Any other recomdations. How much horsepower do you think I will end up with?
I am waiting for the block to come back from the machine shop.

351M, 40 over bored
272 cam
Proformer 400 intake (non EGR)
Holley 650
Aussie heads
After Market Timing gear (made it zero)
alum water pump
MSD 6A
MSD dist
Blackjack Headers
8m wires
Stock pistons

 

[updated:LAST EDITED ON 15-Mar-02 AT 09:34 PM (EST)]id stop at .30 if you can. these blocks dont like going to far. as for power, id say 250-330hp

 

I Would go with a speed demon carb, I have not had good luck with any holley carb but i havn't had a change to personally check out the new truck avenger carb

Good choice on the dist. i have heard of 9.5mm wires and with a high output coil u will get better spark(so i have heard)

I wouldn't go with stock piston's

Just my opinion. good luck

ford man

 

Art,

In your "351M Emissions" thread, you didn't mention the Aussie heads. Do you have them yet, or are you just considering them? You also mentioned TRW pistons in the emissions thread and stock pistons here, so I'm wondering the same thing about them.

The reason I'm asking is that I'd suggest you build that engine as a 400 instead of a 351M. The 400 has more power potential. If you've already invested in some expensive 351M-specific parts, such as the TRW pistons, then it's a tougher decision. Also, the Aussie 302C heads will produce very high (probably non-streetable) compression on a 400, unless you drop major coin for some custom pistons.

My other recommendation is regarding the camshaft. I recommend a dual-pattern cam, with more duration and lift on the exhaust lobes. I've seen good results with the Comp 265DEH cam, and I've heard of good results with more aggressive cams. I've seen decent results with milder dual-pattern cams, such as the Comp 255DEH and Edelbrock #2172. I have also seen some rather disappointing results with single-pattern cams (even very aggressive ones) in M-block (351M/400) engines. I strongly recommend against using a single-pattern cam in an M-block.

I'll second the Demon carb suggestion from x_FordMan_x. The Demons work better than anything else you can get without hours of dyno tuning, and they use most of the Holley-type trick and tuning parts.

 

BubbaF250 is right on!

Check your compression ratio very carefully with aussie heads.

Dual pattern cams seem to always work best with Fords.

Pick a cam manufacturer that offers a full range of grinds. Call their tech line and work very carefully and HONESTLY with the tech rep to pick a cam. Ask questions, but don't argue with them, they are there to help. Remember, everything is a compromise. Follow the rep's suggestion to the letter, don't even try to second guess them. They have mega hours/years of experience to draw from. More than any of us "saturday armchair mechanics" can ever have.


over!

 

Ok. hope I did not mess up! I have the Aussie heads. (paid $345)I changed my mind about the TRW pistons due to the price. Will I be alright using the stock pistons?
Let me list the part numbers of what I have.

Aussie heads 58.4cc "quench", 2v intake ports 1.34"x2.00, 2v exhaust ports 1.33"x1.78". intake 2.04 intake x 1.65 exh seats.

Crane Cam part # 133042, grind 2712 H1O

Edelbrock performer 400 non EGR, part # 2171

Holley Model 4165 650 cfm spread bore with adap plate.

BlackJack Headers

Block is going to Mech shop on Monday.

New Timing gears (zero)get rid of 4degree retard. Did I mess tis up?

 

you know, if you hav not ordered any thing, id look at paw for a 400 crank, and then go with 400 pistons. this will turn your 351 to a 400. and that power increase will be worth the money spent. just a thought.

 

Any salvage yard could fix you up with a 400 crank also. There be zillions of them out there.

over!

 

re-buildup>>>>I am almost ready to fire off my new rebuilt 400----i installed the same cam that you have---you should really go ahead and pickup the valve springs , and the fulcrum kit that crane recommends for that cam for your rocker arms---additionally , you might consider having the machine shop install a set of same size stainless steel valves in the 400 heads if you decide not to use your aussie heads due to the CPR being TOO high as well as having hardened valve seats installed to complement the stainless steel valves-------Look into aset of ohio pistons (flat tops) which are rated at 9 to 1 ----Ideally you would like to get as close to 10 to 1 as possibly without going over----makes buying gas a much easier job----in the end you want an engine that you can drive every day and not have to jack with it all the time-PI ***---The 400 stock heads if reworked by a comptent machine shop per the above suggestions will give you close too OR ABOVE 400 hp which is more than enough to make sweet thang get her drawers wet!!!!!!!!!!!!fd

 

>... the Aussie 302C heads will produce
>very high (probably non-streetable) compression on a 400,
>unless you drop major coin for some custom pistons.
>

Bubba - if the 400 has 8.5:1 (or so) compression, wouldn't the Aussie heads only bump compression to about 10:1? Are you saying that 10:1 is too high or are you saying it would really go much higher? I've heard that with the closed chambers, and particularly if you polish the chambers, you can go to 11:1 on 92/93 octane pump gas.

I am at a decision point of throwing my Aussie heads on my 351C (currently 9:1, would go to 10.7:1 with Aussies) or build a 400 which would go from 8.5:1 to about 10:1 with the Aussies. Am I off base here? Is the effect on compression different on the 400 as compared to the 351C due greater stroke/displacement? Thanks!

 

:-staun

It's been a while so here goes.

From what I understand the small chamber heads will yield about 1.5 points over stock. Should be 9.5-10.1 depending on thickness of head gasket and milling of block/head surfaces.
(There is an old mechanics tip of doubling head gaskets to reduce compression about 1 point. Keep in mind that I've never tried this and it probably won't hold up to any serious power.)

The cam you chose will be just right for the 351. If you go the 400 route you will wind up with a low revving torque monster. Mine didn't like anything over 4500 (400) with the same cam

Opinions vary on the amount of h.p you will produce. Some claim lower than similarly equipped 351 W. I say b.s. to them.

I had stock 400 .030 over. Ported stock heads. same intake, headers, ignition etc. Different bigger cam. (Wolvering blue racer 280? something) stock pistons, 750 edelbrock carb.

I don't know what the h/p was, but it ran pretty hard. I never had any trouble with 350 chevy's unless they were really hot. The best I ever did was 15.20 qtr mile. In a 5000 lb truck w/ truck 4spd and street radials. This at 5000 ft elevation 110 degrees in shade and really bad starting line.

If I had any advice it would be to go to the 400 unless you want mpg. The rods on these engines don't really like more than about 6 grand before they begin to show the stress. I've heard that 6500 is pretty concrete for failure. Don't really know, I never went over 5500. That's why chevy's are so good for rodding, you can usually twist 6500-7000 from a mostly stock (good rod bolts) bottom end. We don't have that luxury unless you find better rods. More advice would be port the heads!!!!! It's easy to do yourself if you want. And the yields on these type heads are awesome for very little effort. Just smooth out the big ridge under the valve and polish the rough edges out of the chambers.

You already have a big step in the right direction going for more compression. The cast pistons don't really like super high rpm, but I've never seen any scuff/fail from the h/p a stout street engine will produce. I think your money would be better spent elsewhere unless you plan on nitrous/blower. The cranks in these things are stout enough, just make sure it's not cracked. Headers/good dual exhaust is must. In short good luck. I think you have the makings of a good honest 325-350 h/p maybe more depending on individual tuning/porting of heads etc. Torque with high compression should be around 400 ft/lb.

Have fun and go stomp on some bowties for me.

 

bbtkd,

Assuming an average chamber size of 60cc for the Aussie 302C heads, and stock 8.4:1 truck pistons with 1.650" compression height and 13.75cc dish, the compression ratio (CR) works out to 9.6:1. Now, if you had a decent quench effect where the piston got close enough to the chamber surface, you could probably get by with that CR at sea level on 94-octane premium. Unfortunately, the deck clearance with stock 400 pistons (0.067") is terrible for quench. I don't think you could keep an engine like that from pinging on 94-octane fuel.

Take down the deck far enough to get reasonable deck clearance for some quench (say 0.050" or so), and now the CR is up to 10.64:1. Assuming you can get decent quench then, I still think that's pushing you beyond premium pump gas.

Realistically, the only way to get usable quench and tolerable CR with Aussie heads on a 400 is with custom pistons.

As for differences between the 351C and 400, the 351C is blessed with a much more favorable deck clearance than the 400 (typical 0.020"), so getting good quench effect with reasonable CR is much easier with the 351C.

Since CR is expressed as the reciprocal of (swept volume)/(clearance volume), the 400's larger swept volume will produce a proportionately bigger change in CR when you reduce clearance volume (approximately 14.3% more CR increase for the 400).