["QUICK-SILVER"]

Originally Posted by footjoy

217 peak horse power

What RPM did you get the 217? and what did the curve look like coming up to that point?

Originally Posted by footjoy

I didn't think you could build a pontiac with that low of horse power. I was hoping for 300.

Something definitely went wrong.

Greg

May not be anything wrong. Could be closer to 300 raw flywheel horse power than you think. 300 horse 400's had 250 net horse power. That's with all the accessories on the front of the engine. Take away hp required to operate the transmission and rear end....217 wouldn't be off far at all. Transmission by itself could be using 30~40 horse power.

Clay

[Lee]

Oh, what do have for exhaust?

If you have decent headers and a good system behind them, then you may see 240's.

But if you have log manifolds still, or a restrictive system, then you are pretty much maxed out.

[slowbird]

Originally Posted by steve25

You need to mill those heads to get the comp up to 9.5 to 9.7 and that will bring the cranking compression to the needed 180 range that the 3.750" stroke of 350, 389 and 400 motors need so to speak.

This means you need a 10 cc reduction in chamber volume, so milling the heads .060" on the deck and the Intake flange will do the trick.

Note that milling this much off the heads means that you will have use only a bead of gasket maker on the valley pan and you might also need to trim some meat off of the bottom of the Intake Manifold to get things bolted up and sealed , but the power gain will be worth your time , money and effort!

Be sure that once the milling is done you lay a head gasket on the head and roll/ polish over any sharp edges of the deck that now stick out passed the fire ring of the head gasket.

Fwiw our 400 has a cranking compression of 165psi and runs 11.4s-11.5s not sure why you say they need 180psi.

[moontower69]

That 60240 is a "relatively" small cam, in CA we only get 91 octane. I wouldn't go over 9:1 with that cam or you're asking for detonation trouble on hot days - unless you're a master carb tuner etc and have a Cliff Ruggles Qjet dialed in, etc. IMHO

Bigger cam like 2801 or 068 will def run a little stronger with 9.5:1 compression but won't be night and day vs. 8.5:1

It opens a longer conversation because 068 designed for higher compression and has wider lobe separation and then the whole debate about "bleeding off the higher compression"

Bottom line, don't sweat the compression you currently have, it isn't make or break on the combo.

[PAUL K]

Originally Posted by slowbird

Fwiw our 400 has a cranking compression of 165psi and runs 11.4s-11.5s not sure why you say they need 180psi.

I just checked my 900 hp E-head engine and it had 160 across the board..... and then I tried a different gauge and it went up a chit ton! I'm going to use the lower numbers when I run pump gas and the higher ones when I'm burning high octane.

[footjoy]

Do you think that 735 cfm carb is to big for 220 horwsepower. Should I rethink the size before I spend time and effort into getting correctly jetted?

Thanks
Greg

[GOAT8U2]

Confirm your torque converter slippage, that could be a big culprit here. Autos eat up more HP in general let alone the converter slippage so I thought...

360hp engine then 280whp with everything near ideal. 12.8 AF seems rich but I'm not sure what the whole pull looks like.

A good use of the dyno is to tune on it too, doesn't sound like that happened. Missed your chance to try some fuel, timing and cam tweaks.

[Firebob]

Still sounds a bit weak to me also. I ran my 30 over 400 with badger cast Pistons, 16 heads and a 226/226 110 cam thru a 4sp at 5000ft elevation and it spun up 297hp/360tq some years back on a portable dynojet machine. I had 195-205 compression and eventually wasted the rod bearings and broke ring lands out of two pistons but it ran pretty good till I pulled it down.

[footjoy]

Originally Posted by "QUICK-SILVER"

What RPM did you get the 217? and what did the curve look like coming up to that point?



May not be anything wrong. Could be closer to 300 raw flywheel horse power than you think. 300 horse 400's had 250 net horse power. That's with all the accessories on the front of the engine. Take away hp required to operate the transmission and rear end....217 wouldn't be off far at all. Transmission by itself could be using 30~40 horse power.

Clay

It made 217 hp at 4600 rpm and the torque was 276@ 3600rpm

Thanks for the question

Greg

[FrankieT/A]

Originally Posted by footjoy

Guess what Horse power this put out?


Build

400 .060
Flat top with one valve relief
Crower 60240 cam
#15 small valve heads 87cc
Performer Intake
HEI 14 initial 35 all in at 3000
Quick fuel 735

AFR 12.8

The answer is right here in the original post...
455 heads on a 400. Low compression no flow...

Try some 12 heads or 48...even 62's would be better.

[steve25]

The casting # 15 heads with there stock 1.96" Intake valve peak in Intake flow at 185 cfm, the Exh side even though it only has a 1.66" Exh valve flows 155 to 158 cfm.

The overall flow ratio is in the low 82 to 84 percent range which can mean that even if your pumping out the Exh thru stock log Manifolds you do not need a duel pattern Cam like your running.
At the Intake valve lift of the Crower Cam your getting about 175 cfm, this amount of flow will be enough to make a very optimistic 358 hp at the flywheel.

[footjoy]

Originally Posted by steve25

The casting # 15 heads with there stock 1.96" Intake valve peak in Intake flow at 185 cfm, the Exh side even though it only has a 1.66" Exh valve flows 155 to 158 cfm.

The overall flow ratio is in the low 82 to 84 percent range which can mean that even if your pumping out the Exh thru stock log Manifolds you do not need a duel pattern Cam like your running.
At the Intake valve lift of the Crower Cam your getting about 175 cfm, this amount of flow will be enough to make a very optimistic 358 hp at the flywheel.

What cam do you recomend?

And how do I get anywhere close to that 358 hp?

Thanks

[HWYSTR455]

If it runs good all around, and you want more, just spray it. A 125hp fixed kit is not that expensive, and usually typical ring gaps will tolerate a 125 shot.

Still missing info, like is the intake ported/port matched? Any work on the heads? Converter/trans/rear gear? Type of exhaust? A 72cc head swap would be a good choice, and swap the intake.

735 carb should be fine on that.

If you're considering a cam swap, I don't think you will see any noticeable diff with a 2801, 2802 would be better, but then you're talking about making other changes to take advantage of it.

.

[footjoy]

Originally Posted by HWYSTR455

If it runs good all around, and you want more, just spray it. A 125hp fixed kit is not that expensive, and usually typical ring gaps will tolerate a 125 shot.

Still missing info, like is the intake ported/port matched? Any work on the heads? Converter/trans/rear gear? Type of exhaust? A 72cc head swap would be a good choice, and swap the intake.

735 carb should be fine on that.

If you're considering a cam swap, I don't think you will see any noticeable diff with a 2801, 2802 would be better, but then you're talking about making other changes to take advantage of it.

.

performer intake no porting 2200 converter 3:73 rear stock 15 heads 87cc needs to be streetable

[HWYSTR455]

Spray is streetable, as is the 2802. The 373s, not so much in many's opinion.

72cc heads, Perf RPM (if you can fit it) port matched, and a 2802 would be a considerable bump. Totally streetable. You could even spray that.


.

[1funride]

I have the 72cc heads on my 400 with a cam not much different than the 2802, very streetable, easy cruiser. I made 276 to the wheels with a dyno jet, I had a rusty flowmaster exhaust on it and a flex fan. I changed to a straight through magnaflow and that made a big difference on the mid to top end power. I think with a fan change I could be approaching 300. I would swap out the heads to 72cc and get a little bigger cam, then you will have a snappy engine.

[footjoy]

Originally Posted by 1funride

I have the 72cc heads on my 400 with a cam not much different than the 2802, very streetable, easy cruiser. I made 276 to the wheels with a dyno jet, I had a rusty flowmaster exhaust on it and a flex fan. I changed to a straight through magnaflow and that made a big difference on the mid to top end power. I think with a fan change I could be approaching 300. I would swap out the heads to 72cc and get a little bigger cam, then you will have a snappy engine.

What converter would I have to use with that cam?

Thanks

[1funride]

I have a TH400 with 3.42 gears, Hughs GM25BPO400BP converter, I believe its a 2500 stall. The cam is an ultradyne 274/282 226/233 with .515 lift intake and exhaust with 1.65 rocker, LSA is 112 ICL is 107. Converter is tight on the street and you cant notice its there, does offer some performance increase though.

Not a drop of ping and I run 89 octane, the cam is mild, idles with just a hint of performance, is very responsive on the street. If you search my posts there is a image of the dyno runs and also video link to the dyno run. That was with the flowmaster exhaust, the magnaflow exhaust definately added power and responsiveness, it was quit noticeable.

[1funride]

http://forums.maxperformanceinc.com/...d.php?t=822814

["QUICK-SILVER"]

Greg,

Check this thread out. First page has "engine dyno" numbers. And the owner posted professionally tuned "chassis dyno" numbers today. Nearly 150 HP difference.
https://forums.maxperformanceinc.com...=808474&page=5

Your engine could have A LOT more than you think.

Clay