Your donations help keep this valuable resource free and growing. Thank you.
|
304 on the dyno |
Post Reply | Page <1 34567> |
Author | |
jcisworthy
AMC Addicted Joined: Jul/23/2009 Location: North Carolina Status: Offline Points: 2805 |
Post Options
Thanks(0)
|
This is an automatic 700R4 trans 354 gear, 26" tire and a mild converter application.
With this cam I called Bullet to order and told him what I had for lobes and LSA, ICL then he recommended a slight change and I told him to go for it so he did. Typically, I order a cam with the lobes I want from the Bullet master lobe list. I choose LSA and ICL based on the customers desire for the engine then adjust compression for cylinder pressure. So far it has been working out well. Of course cylinder heads and intake play a large part also.
|
|
Specializing in dyno services, engine building, and cylinder head porting
rbjracing.com Phone Number 518-915-3203 |
|
Trader
AMC Addicted Joined: May/15/2018 Location: Ontario Status: Offline Points: 6881 |
Post Options
Thanks(0)
|
Thanks
And rightly so, you cannot look at a single aspect but the entire combination of engine components, transmission, gearing, application, customers plans, etc. Likely people being the hardest part of the equation! By the math I'm using: Just for your interest, take it or leave it, from 2000 to 4500 RPM a 304 has the highest torque at 22° and a 401 at 24°. The drop off power curve puts the exhaust open at 70° BBDC on a 304 and 68° BBDC on a 401 assuming your using the 111° separation angle and 107° ILC. These numbers seem very static unless there is a drastic change. A torker intake vs a dual plain being a big one. The torker likes lots more overlap by the numbers I'm using. Look forward to your next build!
|
|
Sonic Silver
Supporter of TheAMCForum Joined: Nov/23/2011 Location: East Tennessee Status: Offline Points: 7949 |
Post Options
Thanks(0)
|
What is the number for a 360 engine, if the 304 is 70 BBDC and the 401 is 68 BBDC? If the exhaust valve opens before this, do you lose some cylinder pressure and torque? If it opens too late, what happens, detonation? Thanks. Edited by Sonic Silver - Mar/06/2019 at 9:18pm |
|
Trader
AMC Addicted Joined: May/15/2018 Location: Ontario Status: Offline Points: 6881 |
Post Options
Thanks(0)
|
I will explain best I can as I don't have the excel knowledge to graph this.
The intake closing, cylinder diameter, stroke and cylinder velocity all contribute to charging the cylinder. There is a peak period for the intake to close to obtain the highest gas charge. The timing and detonation of the charge at a set RPM will dictate the crankshaft angle with the most power to the crankshaft. This is a lot more like a spike then a curve compared to a valve opening curve. As the spike starts down the cylinder pressure is dropping but there is a point that pressure vs calculated torque fall off very quickly. Everything seems to be a compromise. In a perfect world, a low RPM engine will use all the available power. The higher up the RPM you set the goals. Typically 3000 RPM to use 80% to 85% of the available power. This can be calculated to the exhaust valve opening point. This in turn sets your degrees of duration, overlap ... So now you have numbers for intake open, close, exhaust open, close. Type of valve train drive will dictate how aggressive you can make these points and also how much lift. Then you can take your valve sizes, lift, head flow, intake flow, exhaust flow and calculate the charge and pressure to get a torque/HP number. And no I have not calculated a 360 as it takes still over an hour to come up with one engine combination. |
|
austinsamx74
AMC Apprentice Joined: Nov/10/2016 Location: pa Status: Offline Points: 203 |
Post Options
Thanks(0)
|
Did you use early 304 heads too get your compression or custom piston .Thanks just curious
|
|
jcisworthy
AMC Addicted Joined: Jul/23/2009 Location: North Carolina Status: Offline Points: 2805 |
Post Options
Thanks(0)
|
086 castings with a custom 5cc piston set at zero deck
3.8" bore with Cometic 3.810 bore .040 compressed MLS gaskets
|
|
Specializing in dyno services, engine building, and cylinder head porting
rbjracing.com Phone Number 518-915-3203 |
|
BMOgremlin
AMC Nut Joined: Sep/01/2019 Location: Deer Park washi Status: Offline Points: 285 |
Post Options
Thanks(0)
|
what all did you have to do to run the Ls1 rockers?
|
|
PHAT69AMX
AMC Addicted Joined: Jul/07/2007 Location: West Virginia Status: Offline Points: 5919 |
Post Options
Thanks(0)
|
The advanced forum search function found this thread:
|
|
mopar440cu
AMC Nut Joined: Mar/29/2016 Location: Florida Status: Offline Points: 261 |
Post Options
Thanks(1)
|
I just saw this post and all I can say is Amazing! I never knew you could get those numbers out of a 304! John is now building my 401 for another project and after reading this I cant wait until the final product.
|
|
This is America. What you believe is not the problem... What you believe I SHOULD BELIEVE is the problem!
|
|
CHAR
AMC Nut Joined: Feb/22/2019 Location: NW Florida Status: Offline Points: 354 |
Post Options
Thanks(0)
|
How much does ringing 363HP out of a 304 cost? I wonder what the money and power deltas would be if you de-stroked a 360 and turned it into a Trasco style T/A screamer?
|
|
72 Javelin SST P code 360/auto/AC/rear defrost /Go Pack/Polar White w blue cord interior.
|
|
Post Reply | Page <1 34567> |
Tweet
|
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |