Frosty's 350hp 318.

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frosty_the_punk

frosty_the_punk

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Hey all, as some of you know I have had some detonation issues with my 318 recently which saw the need to pull it down and have the bores honed and a new set of pistons.

Specs this time are as follows
318 +.040
10.2:1 compression
915 J heads, ferrea 5000 valves 2.02/1.6 slight bowl blend.
Scat H beam rods + Icon IC845 dome top forged pistons.
Comp thumpr camshaft 227/242 @ 50" 107 LSA. .486"/.473" (102ICL)
Edelbrock Performer RPM with 650CFM AVS carburetor
4 into 1 headers, 1-3/4" OD x 30" long with 3" collector.

I decided to have it dyno tuned this time before I put it back in the car, that way it's tuned and ready to go.

It was a very straight forward dyno session with not so much as a jet change needed. we optimized the ignition and tested a few plugs of different heat ranges.

I got a bit of video and a printout of the numerical readout, but i have converted it into a graph via a website. I will upload the readout and videos in the morning.

re: the numbers. it made 352hp at 5700 RPM and 367lb-ft at 4400 RPM.
the thing about this motor is it has a really wide torque curve, with over 350ft-lb on tap from 2900-5100.

I'm really pleased with the results especially with the bad rap the thumpr cam gets for being all about the idle etc. Should be a plenty stout street motor!

Also noteworthy it made 60psi of oil pressure at idle and 77PSI at peak RPM which is very high lol. Maybe the mopar performance high volume oil pump wasn't necessary.

 
Nice engine. I think you'll be happy with it.
On the oil pressure... IMO, very few engines need a HV oil pump. If you run factory clearances then you don't need it. I can guarantee you that there's another 15-25hp or more and 30+ pound ft or torque tied up only in running that oil pump - especially at high rpm. You only need a max of 60psi by that dyno test and currently it's bypassing pretty much all the time. That's a lot of wasted energy and heat being put into the oil.
 
moper said:
Nice engine. I think you'll be happy with it.
On the oil pressure... IMO, very few engines need a HV oil pump. If you run factory clearances then you don't need it. I can guarantee you that there's another 15-25hp or more and 30+ pound ft or torque tied up only in running that oil pump - especially at high rpm. You only need a max of 60psi by that dyno test and currently it's bypassing pretty much all the time. That's a lot of wasted energy and heat being put into the oil.
Click to expand...

what about when his engine is broken in, and has larger bearing clearances? when it's running at low rpm or idle and the engine is at temp, the oil pressure will be higher. standard pumps tend to have lower oil pressure at idle once an engine is broken in and the engine is warmed up.

so if he's doing a lot of driving, any stop n go, long trips in hot weather, etc.... the hv is better.

if he's high rpm racing all the time, yeah that 10hp he lost might be important... but even in high HP engines (like hemis) they will put oil systems to flow even MORE oil than an HV pump. and they carry 10qts down the track with them also.

i ran a 340 years ago, had HV oil pump from day one. at 50000 miles the bearings looked like the day i installed them, and clearances hadn't changed. and i ran the #!#%$ out of that engine.
 
Thanks guys, I'm going considering swapping the HV pump for a standard item to reduce stress on the drive gear. not sure what I'm going to do yet.
 
Thats a nice stout 318 man!!!! Very kool! I put a HV oil pump in mine, I have good oil pressure i'm happy with, but after reading that its not needed, oh well, im not going through all the work to change it out. PITA!
 
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