Personal 380 SBC Dyno

[user-9274568]

Cam looks like it'll live a long life, pretty mild on the lobes - low maintenance engine?

Did you try winding the cam back to 103ICL? - I reckon it may be happier there, but I may be wrong!

I can see 700hp pretty easy with another 4 deg duration on both sides, 103 ICL & slightly more aggressive lobes - say .430" lobe lift.

It's a damn good starting point as it sits!

Would be interesting to run it on E85.

Bracket Engine, no maintenance was the plan.

The cam is in at 102.5ish. It has a .435 intake lobe, .422 exhaust. It needs more lift, IMO.. I wanted it to peak at 7-7200 with that stock block.

I say it ran out of head with 2.32in MIN CSA.

[cgarb]

Wow, that has close to 100hp on my 377, and it looks mean too...lol. Nice build.

[KnightEngines]

I dunno that you ran out of head, I would expect a smaller spread from peak TQ to peak HP & a faster lay over up top if heads were the limiting factor.
I agree it wants more lift.
If the cam was bigger & produced a similar curve I'd agree heads are holding it back, but with that cam I reckon it's more cam limited than head.

Thought I read the cam was in on 101 ICL & she was high 600's lift with 1.7 rockers?

[MadBill]

Great looking engine and matching results!
Just curious, did you happen to do an A-B without the vacuum pump?

[tuffxf]

Very nice!

[induction apprentice]

no critisisms here. I would be very proud if that were one of mine. Very impressive engine.

[Carnut1]

Nice project Chad! Love the port design. 205cc is before you CNC it? From the pics that port looks much bigger. Thanks, Charlie

[user-9274568]

I dunno that you ran out of head, I would expect a smaller spread from peak TQ to peak HP & a faster lay over up top if heads were the limiting factor.
I agree it wants more lift.
If the cam was bigger & produced a similar curve I'd agree heads are holding it back, but with that cam I reckon it's more cam limited than head.

Thought I read the cam was in on 101 ICL & she was high 600's lift with 1.7 rockers?

It wouldn't let me change it after I noticed I put 101..

The loss at the retainer was way more than with a soft spring. Not sure why.

[user-9274568]

Great looking engine and matching results!
Just curious, did you happen to do an A-B without the vacuum pump?

No, we made the first pull with the pump. I wanted to crank 18+ in it for a hero run but decided that wasn't how I was going to run it anyway.

[user-9274568]

Nice project Chad! Love the port design. 205cc is before you CNC it? From the pics that port looks much bigger. Thanks, Charlie

No, it's 205cc after CNC..

2.32in² MIN
63cc chamber
1.320 x 2.250 opening
Mr Gasket 5823 (trim)
2.37in² AVG CSA
5.40 port length
205cc runner*
2.08 intake w/30º BC
1.600 exhaust
45º seats

[KnightEngines]

It wouldn't let me change it after I noticed I put 101..

The loss at the retainer was way more than with a soft spring. Not sure why.

Good ol typo.

Well done man, it's a nice engine that'll do plenty of passes between freshens.

I've always wondered if lift loss at the retainer from deflection actually occurs to the same degree in a running engine as you see on the stand - inertia of the valve train (same thing that causes loft if the springs aren't up to the task) may well negate some of the losses you see on the stand.
Dunno.
I think too much.

[user-9274568]

It wouldn't let me change it after I noticed I put 101..

The loss at the retainer was way more than with a soft spring. Not sure why.

Good ol typo.

Well done man, it's a nice engine that'll do plenty of passes between freshens.

I've always wondered if lift loss at the retainer from deflection actually occurs to the same degree in a running engine as you see on the stand - inertia of the valve train (same thing that causes loft if the springs aren't up to the task) may well negate some of the losses you see on the stand.
Dunno.
I think too much.

All I know is lift loss is frustrating as hell...

[tresi]

Bracket racing you say? Will we see it at Great Bend?

[user-9274568]

Bracket racing you say? Will we see it at Great Bend?

Yes, only place I will probably go rest of this year. Going to try and be ready for Aug 5th.

[Carnut1]

Nice project Chad! Love the port design. 205cc is before you CNC it? From the pics that port looks much bigger. Thanks, Charlie

No, it's 205cc after CNC..

2.32in² MIN
63cc chamber
1.320 x 2.250 opening
Mr Gasket 5823 (trim)
2.37in² AVG CSA
5.40 port length
205cc runner*
2.08 intake w/30º BC
1.600 exhaust
45º seats

Chad, any chance of a port energy graph of these bad boys? Thanks, Charlie