Here's some pics at the Dyno to get a "before" results of upcoming engine mods. The results were pathetic for a big block and what hp/torque I thought it had and what the dyno said were way off. I basically have a GM reman. crate 454 (1988) with truck peanut port heads, Comp 260 cam, Performer manifold, Quadrajet Carb. The rear wheel HP was only 190 and torque was only 335. [img]/wwwthreads_images/icons/frown.gif[/img] In the factory specs, that year of engine should produce around 230hp at the crank and after going through the 465/205/14 bolt, it could be contributing to the low rear wheel HP. I thought the 454 with the cam, performer manifold, and headers would have more HP but maybe not. I think my peanut heads are the bottle neck. Future mods are GM 049 oval heads milled, with 2.19 valves, and Holley MPFI. Maybe a different cam but I'm not sure on that yet. I encourage anyone that thinks their big block has over 500hp or their small block has over 450ft-lbs to actually dyno it before you start posting magical figures. The rear wheel horsepower will always be less than at the crank. I had to run my small wheels/tires in the rear since the Swampers wouldn't fit on the dyno. The small tires will actually improve dyno figures since they don't weigh as much. I can't wait to go back with the new heads and MPFI to see how much those will add.

She's strapped down and ready to go-



This was taken at 90mph!

Rich was really hoping those straps would hold!


Shawn
87 K5
few mods

Not only would you do worse with the swampers because they´re heavier, you´re "effective" gear ratio is way off with the smaller tires (which you don´t normally use, do you?[img]/wwwthreads_images/icons/smile.gif[/img]). What I mean is; you geared your truck to work well with your swampers. If you then go with smaller diametre on your tires you will greatly improve your acceleration and torque.
About the cam: If your truck is geared right, and I suspect it is[img]/wwwthreads_images/icons/smile.gif[/img] it´s a beauty, I think you could go with a slightly "hotter" cam, such as the comp cams 270 (which is about the hottest you can go with stock converter)....or if you wanna change heads, why not try rockerarms with more ratio (1.6 instead of stock 1.5). More lift is a good thing, as long as the springs can handle it.....aah, what the hell do I know? I´m just a stupid swedish guy.

Andreas

If a Blazer runs smooth, it isn´t really a Blazer[img]/wwwthreads_images/icons/crazy.gif[/img]

LOL on your last remark Andreas! Yes, I failed to mention that. It's geared with 4.10 but soon to be 4.88. Have the gears now, should be installed Wednesday. Time for another sick day at work... I'm thinking about a Crane dual pattern 133941 which is a 272 Max Velocity with matching springs. I was also thinking of the Comp 1411 roller-ball rocker arms but I'm not sure if they have a different ratio than stock. I think Big blocks have a different ratio than a small block. Now if I can just get off my butt and do this...

Shawn
87 K5
few mods

Hey Shawn, look into the Comp Cams Extreme 4x4 cams. They're designed for peak torque down low in the RPM range, while maintaining good vacuum and drivability. I have my Comp Cams dealer book at home, I'll get you the specs if you want.

<font color=green>Evan</font color=green>[img]/wwwthreads_images/icons/crazy.gif[/img]

<font color=red>- Contagious Off-Road -</font color=red>

Ok, that would be great. The Crane model was suggested by BC Engineering in Colorado (makes the BBC cam oiler) and they do extensive SB and BB testing. I've also heard good things about the Comp Extreme 4x cams.

Shawn
87 K5
few mods

Nice to see more ppl cheat off from work[img]/wwwthreads_images/icons/laugh.gif[/img] I have a Phd in false "call-in-sick"´s [img]/wwwthreads_images/icons/laugh.gif[/img].
About your 454. I thought peanut port and oval port was the same thing? Guess not...Anyway, if you do get new heads you might aswell get ones with a bit smaller combustion chambers to increase your compression. About 38:1 would be just right...hahaha...kidding (really). Seriously, if your comp-ratio is stock and you go with a hotter cam, an increase in compression by one point is OK, even recommended by some manufacterers. Conclusion: Oval port heads, hotter cam, a bit higher compression, Holley injection, roller rockers and 4.88 gearing and maybe, just maybe, you can get 195 hp and 350 ft.lbs at the rear wheels [img]/wwwthreads_images/icons/wink.gif[/img]

Andreas

If a Blazer runs smooth, it isn´t really a Blazer[img]/wwwthreads_images/icons/crazy.gif[/img]

Peanut port is smaller than oval and not reccomended for high performance use. The 049 heads are suggested by an excellent book called Big-Block Chevy Performance for low end torque and mid-high range power:


I did have them fitted with the 2.19 SS valves and seats.

195 hp and 350 ft.lbs???
I thought MAYBE 192hp and 340lbs.... You can never get that much out of a big block... [img]/wwwthreads_images/icons/smile.gif[/img]




Shawn
87 K5
few mods

Yeah, I´m sorry. I was just reading on some top-fuel and super pro mod sites. Those cars have about 195 hp I think. Must be the blower...d*mn cheaters[img]/wwwthreads_images/icons/laugh.gif[/img]

Andreas

If a Blazer runs smooth, it isn´t really a Blazer[img]/wwwthreads_images/icons/crazy.gif[/img]

Sweet looking truck. It is very true about what you said when people run their mouths off about how much power they make and have never visited Mr. Dyno. Keep up the good work and trust me, there is tons of power hidden in that engine. This is off the subject, but our drag boats engine is a Chevy LS6 block 500 c.i.d. with symetrical port Chevy heads by Reher Morrison, all normally aspirated made 1120 hp,and 765 ft/lbs at the dyno last week. Only if she would fit under your hood.[img]/wwwthreads_images/icons/smile.gif[/img]

Thanks. If you were to give me that motor (when pigs fly) I'd make the motor fit! Thats some incredible power. Sometimes I wish I had an old Camaro. I'd get the largest cam, alum. retangle port heads, 10 or 11 to 1 comp, huge carb or mega FI, etc. With any 4x, it still needs good low end power and be able to run on pump gas...

Shawn
87 K5
few mods