86IROCTHD

bout to put on a set of ported and polished L98 aluminum heads on my car with 1.94/1.50 valves..... what kinda hp gains u think i can get out of these heads....i have headers, ignition, custom chip, and cam has a lift of .423/.446 112 lobecenter ithink..and dur@.050 is 204/214... or should i save the head for a 350?

tpi_roc

you'll be lucky if you make ANY hp

You're going to be lowering your compression into the 8's

Save them for a 350, thats what they're made for.

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1985 Iroc-z, 14 second 305, new engine in the works.

Vader

Now if you could just get that 305 case bored to an even 4"...

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Later,
Vader
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If you want to beat the World, it might reach up and pull you down...
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86IROCTHD

wrong they are 58cc combustion chambers..... these are the aluminum heads not the cast iron heads...... these were on a vette

rezinn

Im running those heads professionally ported and an LT4 cam with 1.6rrs. With ported intake and full exhaust Im running in the high 13s in my 305, so about 260rwhp. The heads made a big difference.

ViciousZ

iTrader: (1)

Yup, the vette heads are a 58 cc head so you won't lower your compression ratio. But you ought to consider that an aluminum head usually tolerates 1 full point more compression ratio than the same cast head since aluminum dissipates heat better. For example, I've got a set of ported and polished vette heads on my 350 and my c.r. is 10.5:1.

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91 Z28
Come see The Vicious...

PALM BEACH IROC-ER

Trick flow (Summit # TFS 31800100) 18 deg. heads flow 325 cfm intake/ 235 exhaust w/ 2.15" intake 1.60" & 58cc chambers for a screamer!

Rob P

iTrader: (1)

My bone stock 92 305 TPI with hollow cat and ported intake plenum and runners put 220hp to the rear wheels on the dyno so 260 with cam/heads/rockers seems like a lot of money for 40hp. I guess go with what you got.

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Rob P
89RSconvtZZ4TPI Edelbrock Intake
SLP Dual Cold Air Intake 1 5/8" Headers Semi-Siamesed Runners, IROC
suspension, alum shaft. Numerous mods.
92Z28convt5spd (stock)
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

E-Z Rollin

Some of you guys need to work on real cars more and read less Hot ROD mags. A 305 can easily make over a hp per cu in with the right heads and cam[gross hp]certainly it doesn't have the potential of a 350. I could have built any[with-in reason]engine I wanted for my S-Blazer but wanted a reasonably quick daily driver. I had an 87 305/310, added ff top pistons,crane 272/454, 87 alum. vette heads. Will bet anyone it puts out over 300 hp [gross].

five7kid

iTrader: (14)

Desktop Dyno has my 305 over 350. Not sure I'd take that to the bank, though.

A doubling of the factory horsepower (155) without touching the shortblock - and still being able to drive it daily.

I'd call that a "real" car.

FWIW, ported World 305's should make more power than ported Vette heads on a 305, all else being equal.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4, 2300 stall TC. Ported World 305 heads, Crane PowerMax 2050 cam. ZZ3/4 intake, oil pump, pan & baffle. Accel HEI SuperCoil & module. Hooker 2055 headers, 3" Catco cat & 3" catback w/dual-opposite Flowmaster 80. 2.93 limited slip. Spohn SFCs waiting to be installed. AMSOIL syn lubes bumper-to-bumper. Daily year-round driver. Best ET, speed TBD...
57 Bel Air, my 1st car. '66 396, 9.7:1 forged TRWs, Weiand Action+, Holley 750VS w/4150 conversion, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 700 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).

rezinn

Somehow I doubt porting and hollowing out your cat could net you 45 horsepower. FYI your car comes from the factory rated at 205 horsepower AT THE FLYWHEEL. This translates to about 175 horsepower at the rear wheels. If you now have 220rwhp from porting I will eat my new Bush cd.

E-Z Rollin

Just for an example as to what can be with L98 heads check out John Lingenfelter's book on sbc 440 hp/383 L98's ported.

Sitting Bull

The thing you must remember is that DD2000 gives you true dyno horsepower. That is, with no accessories attached and at the flywheel.

It is sometimes off by as much as 5%, too. So you might be running around 335 hp. Subtract another 30 hp or so for parasitic losses to accessories like the water pump, alternator, etc., and you are around 300 hp. Then subtract an additional 25% for drivetrain loss and you are looking at about 230 hp at the rear wheels.

Does that sound right?

GOLD85

why wast good heads on such a lame motor. a 305 is a dog and is only fit for slow camaros and crapy rally vans like the one i own. put those heads on a 327 or bigger.

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when the green flag drops the bull$hit stops

Gold 85 Camaro with no motor, pulled the 2.8 to make way for a 350 wich was pulled this summer because a 406 will replace it. The 406 sports a stock bottom end with ARP bolt holding it togeter, flat top hyper pistons. Comp 282 solid cam(.528 lift with 1.6 rockers) Savin up for my Sportsmen 2 heads right now. still Have the perf RPM and 650 DP i used on the 350. Headers and 3inch exhust. Shooten for mid to low 12s next summer

kingtygr

305's aren't slow if you don't need to beat down every blown viper on the road. So far with my stock L03 I've only been done in by a ford probe lookin thing(couldn't see model, it was at night) and some fool running nos on a nissan maxima or something, (one of the new ones, didn't know you could get nos on one of those). And I wasn't even shifting right.

By the way, any good strips in the colorado area?

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Hondas get all the girls.
Camaro's get all the women.

'89 Camaro RS T-top L03, no mods.... yet.

five7kid

iTrader: (14)

You're flanked by Pueblo to the south; and Bandimere to the north, home of the NHRA Mile High Nationals (and bracket racing most Friday nights, Saturdays and Sundays from April to October).

Come on up to Bandimere and get yourself an "altitude attitude".

EDIT P.S.: I made my first trip down a strip at Colorado Springs in 1978 (1/8 mile track, east of town). I was shipped off to Germany that winter, understand the track shut down the next year - wasn't there when I returned in '82. Shame.

[This message has been edited by five7kid (edited December 04, 2001).]

five7kid

iTrader: (14)

I had no illusion it was estimating RWHP. Or that it would pull that at my altitude. Your losses sound a little high, though. Perhaps I'll ask Santa for a dyno session.

The bud who has the DD2000 says he takes their values, multiplies by .8, puts those into DE2000 and it comes close to the times he runs at 5800' Bandimere.

My 305 combo came out at 362 @ 6000 by DD2000, by the way. Compare that to my '66 396 which the factory rated at 325 hp gross (w/o accessories, at the flywheel, etc.).

rezinn

305 is a dog huh? Tell that to all the L98s, LT1s, 5.0 and 4.6 mustangs in my rearview. Sure, more cubes is better..thats why I will be upgrading this summer, but a 305 is nothing to laugh at. BTW, have you seen the 9 second 305 camaro that was brought up earlier?

Sitting Bull

Yeah, your 305 may be putting 250 hp to the rear wheels. I was just guess-timating the losses to the best of my ability.

From what I've read, the Drag dyno program is too generous by about 2/10 of a second. So a 13.5 should really be a 13.7 ET.

Using the ET estimating formula at http://www.prestage.com/carmath/calc_etmph.asp it says your car should do 14.42 at 94.51 mph. That is assuming your car weighs 3500 lbs and has 230 rear wheel hp.

At 250 rwhp it says you run a 14.03 at 97.18 mph.

Do these numbers jive with what you've come up with?