Dyno day is getting close
Moderator: Team
Re: Dyno day is getting close
Congrats on the successful build! Since it does have splayed mains, i'd say it has a much better chance at survival (and less chance of catastrophic failure if it does have issues).
Re: Dyno day is getting close
Looks pretty good, did you test your collectors, lash, cam timing, spacers?
Tom
Tom
Re: Dyno day is getting close
Collector's...no lash testing or cam timing. Ignition timing, jetting, an air bleed change and swapped collector's. I have and 1.5" super sucker style spacer I would have liked to tried, but it won't fit with this intake due to hood clearance anyway so I didn't bother. I did test with and without my vacuum pump, that was worth 18hp even with my dinosaur ring package.
Re: Dyno day is getting close
Couldn't see in you pic, do you have a well worked out pan on that , kickout, screen, scraper good depth, or close to a stock wrap around pan,
Tom
Tom
Re: Dyno day is getting close
It's a swap meet street strip style oil pan...lol. Decent trap door baffle in the front, a baffle that fits between the oil pump and main cap, no scraper though. Probably another thing I will get when I upgrade into the dart block....a better pan.
Re: Dyno day is getting close
Yes, I was told a poorly designed oil pan will see more of a gain with a vacuum pump.
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Re: Dyno day is getting close
scratch that, its on methanol. But it still looks a bit rich. I was going to say it would make 651 hp, and 570 tq. Man am I good. lol. J/K, but seriously, before you reported the results, I said, 650ish. It will be a fast 650 hp. Just as fast as the typical internet 700+.
Re: Dyno day is getting close
Plenum area is untouched, just a port match to the 1206. It was a little on the rich side, we dropped from 164 jets to 158's and picked up power and changed from -9 to -8 NGK plugs and picked up power then swapped out to 154's and picked up horsepower up top but it cost some torque at the bottom so we stopped taking away jet. We then opened up the HS air bleeds from a .030 to .034's and we picked up power up top and got back the Torque at the bottom so we called it good.
Re: Dyno day is getting close
Hey man, nice build. I can't help but wonder how in the heck there is a 100 hp difference in your motor and Randy 331's motor? They're both very similar builds. Both 421's, solid roller cams, really close on compression ratios, high head flows and all that. I'm not knocking your build, because Lord knows I couldn't come anywhere close to either your's or Randy's builds as far as power is concerned. Just curious as to how a couple of specs being different in small amounts could cause that large amount of power difference.
Re: Dyno day is getting close
I wish I knew the answer to that too...but seriously it's probably a lot in the components. The dyno operator told me I'm giving up a big chunk of power with the ring package I have. More modern rings would be way less friction and free up some. Probably my 50 dollar swap meet oil pan is holding back a few hp in windage issues, my camshaft is an older Crane grind that is probably not optimum for my engine. Its the little things that all add up. I'm on a budget so the free roller cam I received suits me well. It was the best of the few I had to choose from though. That was also my first somewhat serious attempt to port heads...I'm sure someone who does it for a living would look at them and laugh...but its a learning curve. Not that my grinder work is horrible, but laugh and go why the hell did you grind there? Its hard to get HP when you get into higher HP per cube ranges...easily make 650hp with 500+ inches, not so easy with 421 and even harder with 358...not that its not possible, It just takes more effort to get it. I could have tested 3 different cams, recut the valve job and tested different seat angles, ported my intake, tested different carbs...all those things could have made me more power. Randy has a lot of experience and its easier for him to make informed decisions on what components to use. I'll get there someday. Thanks to all that have looked at my build though and for the compliments, there was a lot of work to get that 651hp...I have a new respect for those that get the big numbers.
Re: Dyno day is getting close
Excellent observations. There are so many resources required to build an engine these days, such as degree wheels and mics, ring grinders and rod vices, and so on, that it's a major undertaking just to get one to survive, much less make great power like your engine is.
Re: Dyno day is getting close
Maybe cgarb won't mind me throwing a few thoughts in on this.408 Nova wrote: ↑Mon Jun 04, 2018 10:36 pm Hey man, nice build. I can't help but wonder how in the heck there is a 100 hp difference in your motor and Randy 331's motor? They're both very similar builds. Both 421's, solid roller cams, really close on compression ratios, high head flows and all that. I'm not knocking your build, because Lord knows I couldn't come anywhere close to either your's or Randy's builds as far as power is concerned. Just curious as to how a couple of specs being different in small amounts could cause that large amount of power difference.
1. I have an aftermarket block (dart shp pro) it's likely the stronger block is worth a little power.
2. I have more comp ( his 13.8 vs my 14.8 ) and I got my comp with a custom piston to match the vortec chamber, with custom valve notches based on my cam choise, so my dome is most likely lower and and it has a nice spark plug relief. I can still run extended tip plugs. And I got that comp in a chamber I consider better than the profiler. I have 31* total timing on my 421 and I tried more on the dyno.
3. Not only is his cam an old grind, it's a slow lobe. 40* vs 32* intake on mine, and I have higher rocker. I have .100" more intake lift with a ti valve, more ex duration and lift too. My valve speed would be faster.
4. cgarb most likely still has 400 main size, I have 350 mian and 2" rod journals, so I'd have a bearing speed advantage.
5. My custom piston has gas ports, acumulator grove, contact reduction groves, and .9 mm .9 mm 2 mm ring pack. My short block with the cam and belt drive in it would rotate over at under 10lbs.
6. Mine has steeper than 45* seats. I'd bet that would put power on his engine if done correctly.
7. My Braswell is probably bigger. It's 1.59 v x 1.79 t.
8. But the big difference is induction tract. I welded the pushrod area and widened it and did a lot of CSA work. I'm running a modified 2970 intake, so my whole intake tract is sized for more rpm, and that shows by where both of our engines made peak at.
And I don't want this to be taken as negetive to cgarb because it sure isn't intended that way, but my first atempt at this type of build wouldn't run as good as this one does. I think his engine runs good and I'd say he already has Ideas on how it could be better.
An observation,
cgarb HP/cfm = 1.98
My HP/cfm = 2.46
Randy