422 dyno fail

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Jim Ward said:
An update:

Jack with Valley did a great job giving my motor a once over and found the distributor to get junk (replaced with MSD), spark plugs gapped way too tight as they appeared to never be checked out of the box and the butterflies for the secondaries on the carb hitting the divider in the air gap intake. The motor liked 34 degrees best with 76 and 80 jets. Made 507 ft lbs and 455 hp. There was a slight oil leak out of the front of the intake so when he has it off he is going to gasket match the ports and it’s going in the car. I am a little short of my 500hp goal with the iron heads but he says with the heads milled a little to increase compression (currently he calculated 9.2:1) and a larger cam he believes 500 hp is doable.

Thank you to everyone for tue insight and suggestions on this build.
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Could you post a copy of the dyno sheet ?

Seems like a nice build that someone could even home build with home pocket ported heads
 
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Jack just sent these to me.

9145C3EC-A024-4D94-85B4-38AEFD256474.jpeg


62700B57-22F3-4B46-AECD-67A80F66A070.jpeg
 
The shop called today to tell me they made a pull with a 750 Edelbrock carb and it made 355 hp and 421 ft lbs. I think it should be at least 100 more on each spec.
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Looks like you ended up right at about 100hp more, along with 85ft/lbs.

Notice how much better the bsfc #’s are(than the last sheet previously posted).

Same headers as the last test?
Same carb?
Any carb spacers tested?
 
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Are the headers the same size as what was used in the first session?

Those were 1-3/4 x 3??
 
heads will get you over 500hp my half *** build with 4 more cubes made 527 560 , you should do beter than that , the power is there , good luck
 
Oh I’m aware but my goal was to make 500 with cast iron mopar heads. I knew my heads would hold me back some. I have quite a bit of money in these.
 
Jim Ward said:
Oh I’m aware but my goal was to make 500 with cast iron mopar heads. I knew my heads would hold me back some. I have quite a bit of money in these.
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Maybe Nat just has more cam.

Your builder said a cam change could get you near 500hp.
 
Jim Ward said:
An update:

Jack with Valley did a great job giving my motor a once over and found the distributor to get junk (replaced with MSD), spark plugs gapped way too tight as they appeared to never be checked out of the box and the butterflies for the secondaries on the carb hitting the divider in the air gap intake. The motor liked 34 degrees best with 76 and 80 jets. Made 507 ft lbs and 455 hp. There was a slight oil leak out of the front of the intake so when he has it off he is going to gasket match the ports and it’s going in the car. I am a little short of my 500hp goal with the iron heads but he says with the heads milled a little to increase compression (currently he calculated 9.2:1) and a larger cam he believes 500 hp is doable.

Thank you to everyone for tue insight and suggestions on this build.
Click to expand...
Happy for you Jim in getting this sorted out. You seem pleased therefore well done!!

Compression would certainly wake it up a bit so that option of milling the heads us always there as is more cam. So happy now with more known simple changes in the future. Great build!!
 
My feeling is that 500hp from that combo with the 1-5/8” headers would likely take a cam big enough to push it out of the “street friendly” catagory.
 
autoxcuda said:
Maybe Nat just has more cam.

Your builder said a cam change could get you near 500hp.
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not much more 613 lift with 1.6 rockers 2.08 valves 10.5 compression , also lost power when i went with a victor instead of a fully ported air crap
 
Nat said:
not much more 613 lift with 1.6 rockers 2.08 valves 10.5 compression , also lost power when i went with a victor instead of a fully ported air crap
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What was the duration @.050 and the centerline?

I think that's significant more lift: 613 vs 570? And 2.08 valves vs 2.02. And more compression, 10.5:1. Not sure that compression is going to run off of 91 pump gas. It won't with Calif. blend 91 pump.
 
Nice it got sorted out better.

Butterflies hitting the intake seems a bit strange as that would not let it get full throttle in most every case. Ede secondaries are mechanical with the air door, if something was stopping them, the primaries wouldn't open all the way.
 
I’ve mentioned this before........
When the engine makes noticeably more TQ than HP........when you break it down to basics....... it’s running out of air as the rpm increases.
Induction, head flow, head size, header size, cam area....... and usually, it’s a combination of several of those.

For NA street/strip type builds, when you get into that 1.25ft/lb per ci range, it’s not that easy to make the TQ go up significantly.
Shifting the tq peak up in the rpm band, along with trying to get the curve to fall off slower is what I usually attempt to do, when the tq number is decent, and the HP number falls a little short.
This usually comes at the expense of street manners and low end tq.
 
This is a quick fuel 850 race carb and that is exactly what happened.
 
Is there another page/sheet from that run that has the fuel flow and maybe the air flow numbers?
 
Aaah yes, happy dynos. There was a thread earlier this week on ST or YB where it was claimed a NA engine made made 590 hp with a 232@050 cam. I think I might take my engine out & put the dyno in my car...
 
Bewy said:
Aaah yes, happy dynos. There was a thread earlier this week on ST or YB where it was claimed a NA engine made made 590 hp with a 232@050 cam. I think I might take my engine out & put the dyno in my car...
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That sounds like a builder that was on this forum a few years ago.
 
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