350 SBC HP Guestimates.

I made a post about this in the Camaro section about 4 days ago or so and got zero replies on it. I really hate having to double post, but seeing that it's my first time making a double post I can live with it. I would really like some educated guesses from some of you gurus out there (Mr. Pbody and the like) on what I can expect (hp, tq and 1/4 mile expectations) from the motor I had built that will be going into my 71 Fbody. I believe I didn't get any replies from the Camaro forum people because a lot of the guys that frequent that forum don't know much about building engines (not all of them, but a lot them). This seems to be a much more popular spot for this sort of thing. So here it goes for the second time.

Here's the specs of the engine that'll be shoved into the car within the next month or so.

-4 bolt 350ci bored .030 over
-Keith Black hypereutectic 10.0 CR pistions
-Dart Iron Eagle 2.02/1.60 72cc heads
-Edelbrock Proflow 3500 EFI system (1000 cfm)
-Shneider Hyd-roller Cam --- Duration(244int/252exh @.050'') Lift(.560 int/.
575 exh) Lobe Sep. (114)
-Shneider Hyd-roller lifters
-Proform 1.5 ratio roller rockers
-Dual spring valve springs (not sure what brand)

This will go through a set of Stainless headers (not sure which brand yet, still price shopping) and a catless Magnaflow dual 2.5" headerback system. I'll be running a custom 350 2800-3000 stall converter in a TH400 tranny and in the back is a Custom Ford 9" with a 3.08 LSD. The car is the same Camaro SS listed in my sig and should come out to 3300-3400 lbs. All the bushings that have to do with suspension have been changed out to energy poly, as well as the body bushings and engine/tranny mounts. The rear leaf springs have also been changed to a set of 1" drops, comperable to the sets from Hotchkis, the fronts are a brand new set from Hoog. I'll be running a set of 9'' wide Crager alloys in the back with a nice lower profile street tire in the neighboorhood of a 265/45/17. I know it's not a drag racing setup as it's more geared towards handling, but I'm still going to take it down the track at Firebird a few times a year.

It should easily pass the 400 bhp mark, but I don't know how far into the
400's it'll go. Any educated guesses on how this setup will do?

Based strictly on the parameters provided, Engine Analyzer 3.1 says 462 HP at 6,000 RPM and 454 lb. ft. at 4,500. This may a bit on the optimistic side, but should be fairly accurate. I would think 425 is a "slam dunk".

One word of caution. The compression ratio of 10:1 is a bit on the high side for 93 octane gas and iron heads. Detonation will occur between 2,500 and 4,000. I woukld recomend dishing the pistons to get the ratio down to 9.5:1. You'll give up about 7 HP and 6 lbs. of torque. Hardly enough to make the fuel issue worthwhile.

Jim

Thanks for the timely reply Mr. Pbody.

So you really think the CR with those Iron heads will have detonation issues huh? I had the motor built up by a professional engine builder here in town and he said it should run fine with the setup he went with. But then again, maybe it won't. Do you think think the EFI system will be able to solve some of that?

Also, you said "based stricly on the parameters provided" is how you came out with the number that your engine builder gave you. Are there any more perameters that you could use to come up with a more accurate measurement?

BD,

Flow numbers for the heads, lobe separation angle, intake lobe centerline, ACTUAL chamber volume, deck clearance, intake port volume, header size, and a few others less important. All these can make the simulation more accurate. VERY IMPORTANT: This is a mathematical simulation, NOT a true prediction of actual power. There are too many variables involved to hit it exacatly. The quallity of the machine work will also affect the outcome. The simulator assumes "perfect" work. We've seen as much as a 10% variance, but usually in the 4-5% range. In one case, we hit the value within 2 HP on a 650 HP Pontiac. he sent me all the data, and I ran the simulation. He had the engine dynoed at a shop in San Antonio. We were both pretty impressed with the simulator based on that.

I'm not sure what you mean about the numbers my engine builder gave me.... I AM the engine builder... The program I use is registered to Central Virginia Motorsports, which is our shop, DBA Central Virginia Machine Service.

Check us out! (centralvirginiamachine.com)

Jim

Head Info - http://www.dartheads.com/manager/uploads/Tech%20-%20180%20IRON%20SBC.pdf


Cam info -
1-Part Number - 22074
2-Grind Number - 300-08RH
3-Int. Duration (Gross) - 300
4-Exh. Duration (Gross) - 308
5-Int. Duration (.050") - 244
6-Exh. Duration (.050") - 252
7-Int. Valve Lift - .560
8-Exh. Valve Lift - .575
9-Lobe Separation - 114
10-Int. Valve Lash - .000
11-Exh. Valve Lash - .000
12-Matching Component Kit - 42010

Headers
http://store.summitracing.com/partdetail.asp?autofilter=1&part=HOK%2D2117%2D1HKR&N=4294908216+4294908198+4294925080+4294923429+4294 918680+4294840140+400390+115&autoview=sku


When I said "your engine builder" I was refering to the simulated dyno program you are using. I'm familar with them and have used them before, but most likely not near as accurate as the one you have access to.

I also forgot to mention in my previous posts that the builder that machined and assembled my engine balanced the pistons, crank and con-rods as well. I know this can make a good difference, but I dont know if your PC simulated engine dyno can account for this or not. As far as deck clearance...I havnet a clue. Hell I didn't even know what grind the Isky cam was that he used untill I pulled the cam plug off the back of the motor and checked it out myself. Turned out to be a 108 centerline which will not work at all with the EFI system I'm going to use (origionaly planned to use a 750 double pumper) so I am now purchasing the Schneider and upgrading to roller lifters/cam.