Team Chevelle banner

421 dyno results

64K views 43 replies 21 participants last post by  CNC BLOCKS N/E 
#1 · (Edited)
Spent Friday on the dyno testing 421 pump gas build for a customer, He was looking for a 600 horse pump gas build and we achieved our goals with this build. Torque was very impressive @ 574 FT LBS. Tried to build this with all shelf stock parts so it so it could be duplicated. The good thing this is just a street car and only needed to turn this engine 6400 to make peak power.

Little about the build

Dart SHP block 4.155 bore
Callies 3.875 D/S crank
Callies 6 inch rods
Mahle pistons
Clevite V bearings
Steffs custom aluminum pan
Bullet S/R roller cam 1.000 base circle cam
.904 Morel lifters
AFR heads 220/75cc chambers ( Thanks Tony Mamo )
061040 World intake
Pro Systems carb
MSD Distributor
ATI balancer
Crower SS rockers 1.5
Mellings 10552 pump



 
See less See more
2
#11 ·
Stud mount rockers that's what he had brand new. If he would have bought the shafts I would have gone to a 227 Dart or AFR head.

All in all it came out as planned it did not need a lot of RPM to make peak power with this set up.
 
#7 ·
Looks like a good one Carl! Can you share ballpark cam specs?

You could go into the 'serious" crate engine business!


JIM
 
#10 ·
259/263 SR 108 Lobe sep .626 lift.

I get a few of these engines a year to do and that's enough for me, I have a lot of circle track engines and block work that keeps me pretty busy LOL.
 
#9 · (Edited)
By a GM stock crate engine lie a target master you should be fine.

This exactly what the customer wanted and he is very happy with a 6 speed and 4:11 in the rear he can run what ever he wants for RPM.

I have built a lot of street and strip engines that build peak torque over 3600 and so far no complaints.
 
#12 ·
:thumbsup: Thats a nice street motor just waiting for its turn at the track.
 
#13 ·
I doubt this would ever see any track time, If the customer did not already have the stud mount Crower rockers I would have gone with the 227 Dart or AFR heads and made some real power. LOL

For only needing 6400 RPM for peak power its a great street build and should last a long time.
 
#16 ·
interested...
 
#18 ·
Hey Carl that's pretty nifty.
 
#43 ·
I would expect that combination to be very reliable and to last a long time with no problems. Lower rpm torque and hp with the added robustness and lighter rotating parts of the small block platform.

Home run on the combination Carl!
 
#21 ·
well, i guess some comments were directed at me, lol, so i will respond-i really don't care, i just feel my comments were taken the wrong way
its choices, like some come on here and ride for free(Democrats), others pay dues and support the site
since it was a street build, i was getting at it would be nice to see the char. of the engine at idle up-i know the dyno cant run down low, but it can give idle quality and vac-most people run vac brakes, and you see guys come on here and complain they have no brakes
obs the engine was spec. built for the customer, but it just seems everyone is hung up on the top #, forget about where the engine (and you) will live
that's why i run boost and small cams now, i want it all, top and bottom end torq
i'll leaving the flaming to the 2 engine builders that were on here trying to kill each other, i forget who they were, it was fun reading, but i guess the mods deleted it just when it was getting good
 
#31 ·
well, i guess some comments were directed at me, lol, so i will respond-i really don't care, i just feel my comments were taken the wrong way
its choices, like some come on here and ride for free(Democrats), others pay dues and support the site.
since it was a street build, i was getting at it would be nice to see the char. of the engine at idle up-i know the dyno cant run down low, but it can give idle quality and vac-most people run vac brakes, and you see guys come on here and complain they have no brakes
obs the engine was spec. built for the customer, but it just seems everyone is hung up on the top #, forget about where the engine (and you) will live
that's why i run boost and small cams now, i want it all, top and bottom end torq
If you are running a boosted engine explain how vac brakes work???
 
#22 ·
Sorry..again...don't take my comments wrong.

You've got an excellent point about vacuum and driveability. Idle vacuum wouldn't be too hard to get...but even with that you have to spend some time tuning for it. When dyno flogging, it doesn't enter into the equation usually.

Many folks get starry eyed with big HP numbers and don't fully understand the price you pay for those sometimes. That's one advantage of big cubes...they can make stupid power and still produce decent manners. But to make really stupid power with even a big cubed engine N/A...there will be some gnarly manners sometimes. It all depends on your idea of manners. Some folks like the *spin the heads at the cruise in* sound..so don't want to know there is an engine up there. While N/A my 555" is a touch under 900 HP and to me it drives pretty nice. It can cruise around with 3.07 gears..but it's still a Hot Rod engine. I'm assuming it's going to be a lot different with boost and 20* less cam when I get it finished. Closer to what you said...I want it all! Of course *serious* turbo dudes give up some of those manners to make insane power on top of that!

Thanks for all your posts....they're helping me learn this boosted stuff!


JIM
 
#26 ·
To paraphrase Jim, mine was not a knock on your opinions I always appreciate your posts & I do not disagree at all with your points about drivability.
It was mostly to point out that an engine dyno is not really designed to show this in a power pull.
It's just the nature of an engine dyno as I attempted to explain in my post above :beers:
 
#30 ·
My understanding is the 227's require an offset rocker that is best done by a shaft mounting.
 
#34 ·
ok, I have had enough of being demonized
first off, I want to apologize to Carl, what I wanted to try and get across didn't come out right, i was just trying to say on the dyno you don't see the char. of an engine (street)
in the driving range, idle, etc
you ask about power brakes on a boost engine-a boosted engine has vac. just like a nat. asp. one-wot on a nat. asp engine has no vac, no brakes, until the throttle shuts, same as a boosted engine-i have had over 30 boosted engines, only times brakes were a problem was cam choice, same as any nat asp. engine (KPA, PSIA, MAP sensors show it)-that's why Comp. and others sell band aids or solutions-and that was sort of my point, that's what will show up below 3500
i have been building chevys for 50 years, ran stock and super stock against the best, i grew up with the cars people own on this site, if someone can benefit from what i know, cool
i am not a cry baby, i cried when my dog died, i cried when i got shot (twice) in Viet Nam
and i cried last year when my cat died
maybe my sentence struct. isn't good, not my fault i got drafted out of college and got my head blown off
but when some ******* tries to put words in my mouth that are not true "attempts to marginalize his accomplishment", i have a real problem with that-say false stuff to my face, not the keyboard
if they want to ban me from here go ahead, my cars run fine-i am done with it all
 
#35 ·
Nice engine. Those AFR 220's seems bad A$$. Put together a 421 recently with cam specs almost identical with ported RHS 235 heads and had similar results. Nice that a smaller head can do almost the same.



BTW, hydroboost is awesome on boosted engines. No vacuum or check valves to worry about:)
 
#36 ·
There was no sense to go with a bigger cam pretty much new this engine would be all done around 6500 RPM

What intake and what RPM did you achieve peak power?
 
#44 ·
Spent some time on the pone with Tony Mamo from AFR and if I was looking for a little power go with the AFR 235's but I would probably loose around 40 FT. LBS of torque but gain up to 50 horse and it would need more RPM.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top