Ran across a combination in a recent publication I thought I would share......it is a very stout doable 350 combination for a lot of you that would provide outstanding performance combined with decent streetability.

This build-up was done earlier this year in the publication Engine Masters, which is really a darn good magazine.... I recommend it.

Build-up is:

350 bored .040 over (357 ci)
forged bottom end
10.6-1 cr
Performer RPM air gap Dual plane intake
AFR 195 competition eliminators
CC XR294HR cam (hydr roller 242/248 - .540/.562)
They used a 1.5 rr
1 3/4" Hooker super comps

Results:

rpm..............HP........TQ
3000...........247........432
3500...........290........435
4000...........334........438
4500...........401........468
5000...........459........482
5500...........496........474
6000...........523........458
6400...........530........435

The above numbers are pretty darn stout in my opinion, a 350 that is streetable with hyd roller cam, 530 HP and over 480 ftlbs of torque.

They used a dual plane intake in this article, which bumped up the mid-range torque, but gave away a little bit up top as opposed to a Victor Single Plane, but in relation to our efi intakes, as a rough gauge, I would say this is closest to the HSR in performance..... the Superram would probably be down 30 HP, but up 30 ftlbs of torque, where as the Miniram would probably be up another 10-20 HP, but down 10-20 ftlbs of torque.... or thereabouts anyway.

Vic, I know you were considering upgrading performance a little bit a month or two ago, this might be a cylinder head/cam combination you consider. With your set-up, with a 4000 rpm converter, my simulator says you'd run 10.6's @ 127 mph in good fall air, and still hang in the high 10's in summer air. Converter is the key though.... this set-up is a dog with anything under a 3500 rpm converter as per my sim. (3200lb raceweight - 3.45 gears - 700R4 - 100 ft track)


I thought the article was a rare good magazine article, thus decided to share...... do what you want with it.

 

Good no brainer combo there, for a little 350 those are some good torque numbers lower in the curve.

They did a similar one about 6-7 yrs ago before the elims were out. Took a stock ZZ4 shorty, added the old AFR 195 head and a HR with 248/254 @ .050 and got about 520 ish if I remember correctly.
You can see with better heads you need less cam to make the similar power.

 

thats awsome info! great post!

 

Excellent post

 

Thanks, nice post

Beach, didn't Corky build a 355 single plane with impressive numbers too?

 

Good post!

I am not totally surpised about the HP. It's the TQ at low rpm's that is impressive!

That would have quite the idle, and not a big money build.

 

Exactly. That's why I disagree with the " I don't need that much flow I'm only shooting for XXX amount of HP".

Does the LS7 motor need 360CFM to make 500HP? Nope, but that's what it needed to make it with such a small cam.

 

Thanks guys, and yeah, it is a pretty efficient motor and Cruisin is right in my opinion on the cylinder heads...... the better they flow, the easier you can make power and of course the more peak power you can make. What I like about this set-up is that it uses a hyd roller cam...... pretty cool to see a 350 making power north of 500 HP without having to see 7000 rpm..... idle would be uppity though, but thats the price you pay for power.

Rick, yeah, Corky has a 355 with a baby solid roller cam I think in the area of 236 @ .050" and old AFR 190's with a converted SP..... not too far away from this set-up, Corky actually has a cam that is capable of making a few more ponies, but the older version cylinder heads probably do not flow as well as these do in this article..... thus perhaps fairly similar performance between the two motors.

I don't remember exactly what he runs, but I know he's run in the 10's at somewhere north of 125 mph, but perhaps not quite at 130, but not sure. Corky's performance is pretty darn stout if you ask me !!

 

That's what I thought Beach. What I really like about these two engines is cost per performance vs big cubic inch cost. Seems like Corky said out of the 3-4 engines the 355 was most cost efficient.

 

Todd,

Thanks for this info. From the above list, I have the Hooker Super Comps, my compression is 10.5 to 1, I have a 350, 1.6 rockers, and a miniram.

Looks like I just need the heads and cam. I am iching to do something over the winter. I can get a free Stall upgrade from PI, but need to do that in the next 2 months. (their offer is only valid for 2 years).

Looks like those AFR's are the ticket !

Vic

 

that is not a streetable cam...thats more race car than a street motor. I would not want to drive that car. That has 25 degrees of overlap at .050. My 383 cam is sitting at 19.5 and it idles rough as it is. cc306/GM847 etc are always considered stout max streetable cams for 350-355 motors. Those cams peak higher than 6400rpms and i'm surprised that 242 cam didnt peak at near 6800.

 

Hi Vic,

Yeah you're almost their already..... maybe just swap the cam only first and see how it works with your ported heads..... if you're happy leave it alone, if not, you can always slap on some new cylinder heads in the future in an afternoon..... no big deal to swap cylinder heads on an C4 MR motor.

And yeah, it does seem the Eliminator cylinder heads are making good power regardless of what they're slapped on top of..... thats a good thing considering the power those LSx guys make.

 

Yeah it is..... I know this first hand. Idle is rough though and you gotta live with an idle several hundred rpm higher. A friend of mine has been running a very, very similar grind for the past 6 or 7 years. He doesn't own a trailer and drives his car 120 miles round trip to the racetrack every weekend in his Malibu.... never dies or any nasty habits, the only detriment is the idle is a few hundred rpm higher, no big deal...... drives it daily a lot too, but its not his daily driver. As a note, he runs 11.0's at a little over 120 mph in a 3300 lb early 70's Malibu with his 355. Pretty cool set-up he has. I've personally driven this car on the street and raced it.... its great !

On another note, this article was based around building a street car motor as they emphasized in the article, not a race only..... but they did lean to the performance side of things.

 

how do you think tuning to that cam would be still using the factory ecm?

 

For a speed density car you'd have to run open loop for sure. I do not see that cam happening in a 355 sorry. My buddy has a similar cam but solid roller in his 406 and he runs open loop with SD. CC306 cam is hard enough to tune on speed density with 355's let alone that cam.

i guess the definition of streetable greatly differs here. That cam i dont consider streetable in a 355

 

that's using the stock tpi over a new intake manifold ?

 

Vic, I ran across the following article that kind of pertains to above.... they are actually testing a single 4 barrel vs 6 shooter carb, but they use two different cams, one of which is a big cam like used in the article in this thread, the other is a cam that is not too far off from the ZZ9 cam you're running (I think you're running the ZZ9 ?)..... in any regards, what the below linked article shows that with an upgrade from a fairly mild 218/224 cam to a nasty 242/246, based upon the 4 barrel test results, you would lose around 15-20 hp down low, but by around 4000 rpm, the big cam catches the small cam, and by 5200 rpm is 30 hp ahead of the small cam and by 5800 rpm is 50 hp ahead of the small cam.....

Naturally, the right converter would help you compensate and even bounce over the soft stuff down low and in my opinion, you would see a significant et improvement even with the current cylinder heads you have. I'd venture to say a solid 3 tenths if your converter hits where it should.

This of course is not an exact science, and the example is a 383 with over sized 220 cc motown heads, but it does kind of give you an idea of what you might expect with this cam change..... worth a read anyway.

http://www.hotrod.com/testing/hrdp_0...o_results.html

later
Beach Bum

 

Corky and I have lined up a few times, he runs exactly 1/2 second quicker than me.

He is running a solid roller and shifts at 7K , I believe.

My PI cnvertor is coming out this week or next week. I have to send it to them before Novemeber in order to get the free stall change.

I am thinking of having them bump it up by 500 rpms.

Vic

 

Vic what is the rated stall on your current converter ? And what does it actually flash too ?

I know a loose converter worked great for Wheelsup when he had that motor..... thus, seems to reason, you'll pick-up some too.

good luck !

 

4K

4K, It hits 4K when I hit full throttle from an idle. I am very happy with the PI convertor, it hits exactly where I wanted it.

Maybe if I log the run via some software, it might be a bit off.
But just going by my Autometer tach, it is right at 4K.

Vic