[STEELCITYFIREBIRD]

When did HP #'s switch from crank to @ the wheel?

[ponyakr]

Originally Posted by STEELCITYFIREBIRD

When did HP #'s switch from crank to @ the wheel?

Looks like the rating system changed for '72 year models. A 4-barrel 400 dropped from 300hp to 250hp.

http://www.wallaceracing.com/enginesearch4.htm

Then, as CR dropped below 8:1, hp dropped below 200. Smaller cams & exhaust valves may have also played a part in the lower hp ratings.

http://www.classicalpontiac.com/cgi-...bal/engine.cgi

[STEELCITYFIREBIRD]

A good read on this topic.

https://www.hagerty.com/articles-vid.../13/horsepower

[hurryinhoosier62]

Great article. It certainly explains why many of the muscle car engines of the 60s and 70s can't keep up with the modern muscle engines of today.

[scott-462]

Lots of cam talk here, most of which is over my head. From what I've read on this thread and others over the last few years is that my engine is over cammed. My engine build is in my signature. It feels strong down low, even with 2.5X gears it will spin both tires at a 30 mph roll. I now have 3.50 gears. So what's everyone's take on how they expect my engine to run or power it may make?

[tom s]

I just put a SP II in a 455,230-236 on a 112 in at 110,15 in of vac.HSD intake in stick shift car,will lug down to 1500 in OD with no bucking.Likes a 850 vac second Holley .Tom

[PAUL K]

Originally Posted by 400 Lemans

ttt

Why?

[tempest1964]

Not being a wise-arse. I really don't know. What does ttt mean?

[Murf]

To the top.

Sent from my Z936L using Tapatalk

[webfoot]

Why not? I had not seen this thread before and it has some good decisions, and now makes me think I bought the wrong cam!

Should probably be a sticky.

[PAUL K]

Well that was very considerate of you.

[ponchjoe]

Originally Posted by 400 Lemans

Since there have been a couple of cam threads here lately i thought this one might be of some help. So much info in the archives through the years but i don't think they get searched enough.

Thanks, I've read it but got lost in the massive amounts of data, squirrels and disagreements

With that said it does have good info in it you just have to get your sifter out.

[Steve C.]

Here, now they don't have to get their sifter out

https://www.crower.com/media/pdf/2008b/126-128.pdf


.

[pastry_chef]

Interesting build for comparison.
http://www.mondello.com/page9.html

Olds 455 - 4.25 stroke
10.9 compression
Comp cams 42-433-9 XR290HR - 110 LSA
500HP and 604ftlbs on 91 octane

[grivera]

Originally Posted by pastry_chef

Interesting build for comparison.
http://www.mondello.com/page9.html

Olds 455 - 4.25 stroke
10.9 compression
Comp cams 42-433-9 XR290HR - 110 LSA
500HP and 604ftlbs on 91 octane

with a Performer intake

[pastry_chef]

Originally Posted by grivera

with a Performer intake

Even more interesting is why Comp decided to use anemic Xtreme Marine lobes 3355 / 3356 for the Olds XR290HR

The Pontiac / Chevy versions - XR288HR have 157 duration @ .200 lobe lift.

The Olds only gets 146 @ .200.

With 10.9 compression, stock E-heads about 278 CFM and that cam, only 500 HP for a 455 Olds.

[HWYSTR455]

Bernard, Joe's son, owns Bernard Mondello Racing, and he is a straight shooter. His ProComp and E heads are the go-to for Olds.

https://www.facebook.com/Bernard-Mon...8309059257851/

I know the original Mondello Performance was bought out, and I wouldn't trust anything out of that shop. I didn't realize Joe was still in business, may have to dig into that.

http://www.mondellotwister.com/

For a 4.250 stroke engine 455, 500hp is pretty standard as most understand in the Pontiac circles, that can be done with iron heads even. And many build Olds engines that are fairly close to Pontiac builds. So I'm not impressed with it. I think yes, the intake is holding it back, but think many stick with it to be able to run the ram air air cleaner assembly in the Cutlass bodies.

Olds still has a somewhat limited selection of parts, like Pontiac used to be, but it's starting to get a little better. Think DCi now makes a block even, but not cheap. At least you don't have to run a halo, like one would have to in a performance Olds build.



.

[adeeos]

OK, I am also ready to buy a cam for my low buck 455. The rough combo is:

Speed Pro 030 2359 pistons, stock rods and stock crank (bought from a member here) . Bought some 6X-4 heads from a member here in so that my flat top pistons would have a little compression. From the 455 I spun the rod in I have an Edelbrock Performer RPM, Edlebrock carb and some basic headers with 3 inch exhaust. 331 gears, 12 bolt posi. Since I have a another "street/race" car, I am not overly concerned with squeezing every bit of HP from this 455,, but since I am rebuilding it, I'd like all I can get and still run pump gas, be reliable ect.

The cam we picked was the Crower 61909: ULTRA BEAST / PERFORMANCE LEVEL 4 - Hot street profile that delivers impressive mid-range and top end power. RPM Power Range: 2000 to 4800 / Redline: 6200 plus.

This is going in a heavy GTO convert.

Any suggestions on the choice? Is there another inexpensive cam out there that may be a better choice?

Thanks!

[STEELCITYFIREBIRD]

Crower # 60919?

[adeeos]

Yes, that is correct