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Discussion Starter #1
Hi All,

First of all....great forum!

I have an slightly modded 85 and I'm looking for a little...ok...a LOT more power (who isn't). The car has 62K on it and runs good. I'm considering two options.

1. ZZ4 crate motor with my existing TPI and a set of long tube headers with maybe a cam thrown in. This is kinda expensive but gives me a new lower end with a four bolt main. I know I won't get the ZZ4 advertised performance with the TPI but I like the idea of looking fairly stock and I have to watch the budget.

2. Stick with my current block and lower end and install GPP Aluminum Corvette heads (same ones as on the ZZ4), headers, and a cam (ZZ9?). This option would be a lot cheaper and easier and I think would make about the same power as option 1.

The currnent motor seems to be in pretty good shape but burns a couple of quarts of Mobil 1 between changes. It smokes blue every now and then and I think the 18 year old valve seals may be the culprit there. I just fabbed up a leakdown tester and will do some checking on the motor when I get a chance so I can make sure the lower end is worth putting the new goodies on.

With either option I plan to eventually change the intake, maybe an SR, and upgrade the ECM to a later GM model.

Has anyone done similiar mods (GPP heads, cam headers or the ZZ4)? Just looking for some real world experiences.

Thanks!
Jim Sitton
Lenexa, KS
 

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DC PIT CREW BOSS
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Can't really help you with the mods but welcome to digitalcorvettes. Wait til later in the day and some one ought to jump in here.
 

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Welcome aboard Jim! :buhbye:

Option 2 sounds like a better way to go, more money left over for other mods.

Do a search, grumpyvettes has a number of posts that are technical in nature, and can provide you with other ideas to increase your Vettes performance. He has a good post on stroker motors.

grumpyvettes stuff
 

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Official Forklift Driver
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Welcome to DC Jim! :cheers:

I'm not too familiar with any of those combinations but I think the ZZ9 cam is a roller and you'd need to convert your block for it. Thee ZZ4 sounds like a good crate to go with. It's good to hear you want to lose the TPI b/c IMHO, you need to lose it if you want some serious power gains. I have my TPI base, runners and plenum hogged out and I don't think I'll get my peak hp past 5k rpm's. My Hotcam wants to spin past the 5200 rpm's I'm shifting at. :(
 

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El Teafive
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10,489 Posts
While option 2 may be cheaper, I would go with the ZZ4 just to have the comfort of a new motor and alos being a Roller Motor.. Putting a roller cam in your 85 As you will need retro roller rockers.

With the ZZ4 add the ZZ9 cam and Large tube runners.

Another good combo would be:
ZZ4 Short block
ZZ9 or ZZ409 cam (depending on intake)
Fast burn Heads
Vortec TPI base and AS&M runners or Miniram 3
52mm TB

Headers and exhaust.
 

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No help with your question, but welcome to the forum. :)
 

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THE zz4 WILL MAKE FOR A GOOD BASIC ENGINE SWAP BUT YOULL SAVE MONEY, AND HAVE BETTER RESULTS BY REBUILDING YOUR PRESSENT CORVETTE ENGINE WITH A 383 ROTATEING ASSEMBLE AND INSTALLING arp MAIN STUDS AND air flow research 190CC cylinder heads AND A cam THAT matches THE intake YOU CHOOSE. A NICE STREET COMBO CAN BE BUILT ON THAT 383 USEING SEVERAL CAMS, YOUR GEARING , COMPRESSION RATIO AND STALL SPEED WILL DETERMINE THE CORRECT CAM CHOICE BUT CORRECTLY DONE YOUR STOCK CORVETTE ENGINES 230HP CAN BE EASILY BOOSTED TO 400-450 HP
YOULL NEED TO DETERMINE WHAT YOUR BUDGET AND GOALS ARE, BUT YOU CAN EASILY HAVE A CORVETTE THAT KEEPS UP WITH THE NEWER ZO6 CORVETTES IF YOU MAKE THE CORRECT CHOICES
 

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grumpyvette said:
THE zz4 WILL MAKE FOR A GOOD BASIC ENGINE SWAP BUT YOULL SAVE MONEY, AND HAVE BETTER RESULTS BY REBUILDING YOUR PRESSENT CORVETTE ENGINE WITH A 383 ROTATEING ASSEMBLE AND INSTALLING arp MAIN STUDS AND air flow research 190CC cylinder heads AND A cam THAT matches THE intake YOU CHOOSE. A NICE STREET COMBO CAN BE BUILT ON THAT 383 USEING SEVERAL CAMS, YOUR GEARING , COMPRESSION RATIO AND STALL SPEED WILL DETERMINE THE CORRECT CAM CHOICE BUT CORRECTLY DONE YOUR STOCK CORVETTE ENGINES 230HP CAN BE EASILY BOOSTED TO 400-450 HP
YOULL NEED TO DETERMINE WHAT YOUR BUDGET AND GOALS ARE, BUT YOU CAN EASILY HAVE A CORVETTE THAT KEEPS UP WITH THE NEWER ZO6 CORVETTES IF YOU MAKE THE CORRECT CHOICES
Well put!:thumbsup:
 

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now look at this site, NOTICE THE CYLINDER HEADS IN USE WITH ALMOST ALL THE BIG HORSEPOWER ENGINES

http://www.ryanscarpage.50megs.com/combos1.html

if you carefully compare the data youll notice a few things
on average 383s tend to make better hp than 350s
if your building AN ENGINE FROM NOTHING A 383 KIT DOES NOT COST MUCH MORE THAN A 350 DOES and will in almost any combo be almost free additional torque compared to the same engine built as a 350. the cylinder heads and rotating assembly are MAJOR factors in how much power potential your engine has, the CORRECTLY MATCHED INTAKE and CAM will determine to a large extent where in the RPM range the engine makes that power. look over the site and read the links, determine your goals and what your budget will handle.

look at combo #71
youll need a CUSTOM STEALTH RAM and a PROGRAMABLE ECU plus a high stall speed converter and roller cam to use a similar combo in a corvette, but you will potentially have even better hp/tq with the stealth rams longer runner intake

http://www.fasterdeals.com/garageindex.html

the secret to building a great engine is to do your homework and carefully match the engines parts, the most common MISTAKE almost everyone makes is they find ("DEALs") on parts and change the combo, thus ruining the results, just like sticking a tunnel ram intake with dual 1150cfm holleys wont work on a stock 350, or sticking a 250 durration cam in a stock engine won,t work, there are many factors you need to match for good results.
again look at the combo, youll notice that the higher hp combos are all equiped with good heads and most with roller cams, and seldom do you see cams with over 230-240 duration, thats because most of the engines listed are designed to run in the 3000rpm-6500rpm range where longer duration cams have little if any advantage and are not necessary with good flowing cylinder heads
 

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Discussion Starter #17
Whew! Lots to think about and most of it way over my head. I can bolt stuff on, change the heads, cam, etc but I'm no engine builder.

I'm thinking for now, just keep it simple. New heads, headers, and cam and live with that for a while. This is just a street car and I want good low end torque with good driveability and a fair idle.

My budget is around 3k if I'm not going to change the motor. Hmmmm not sure what to do.

Decisions decisions!!! Arrrrgh
 
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