vetracer

I want to build an all-new replacement motor for my '86 street vette. Here's what I have to start with:



It is a new TPIS 52mm TB connected to a TPIS ported plenum modded for the large tube ASM polished runners. I know I will need a bigger intake (Edelbrock ar Accel?) but what about a motor? ZZ4 short block with AFR 190 or 195 heads? Cam? I want a motor that will idle and drive pretty much like the stocker but make over 350 HP. I will probably put the TPIS long tube headers on it but don't want a really loud exhaust system. I don't want emissions equipment compliance to ever be a factor, so I will be keeping the EGR and AIR system (one of the reasons why I didn't go with a mini-ram besides the great looks and high torque of the tuned port). What does the forum think? with the exception of the parts pictured, we have a clean sheet of paper here. The old motor will be stored complete for another project car (maybe a jeep or other 4x4?) so I won't be using the stock heads or anything else. Thanks for the input!




[Modified by vetracer, 10:59 PM 1/27/2003]


[Modified by vetracer, 4:03 PM 1/31/2003]

chucks88

I know some will disagree with me , but slappin' a "Type-R" sticker on that thing will really wake it up :yesnod:

1991Z07

I think I've got the most from a TPI N/A out here on the Forum....

Follow the link to see what I've done to get 400+ HP from a 355 TPI motor....

BTW: I siamesed the base for the rebuild I just finished on it. By all estimates on the F-body forum, I should have 25 more HP and 20-30 more lb/ft of torque from that mod alone. I'm waiting for the new chip to get done and once we have everything tweaked I'm going back to the dyno for another pull.

Mine has a nice little lope at idle :D and has all the emissions equipment.

NavyVet

Shannon, I'll show my ignorance here - why can't you use a miniram and retain emissions? Thanks, Paul

1991Z07

The MiniRam has no EGR in it...he wants to retain all the emissions.


[Modified by Joe90, 5:45 PM 1/27/2003]

gtsyellow

no egr provisions

jmr302

If I was starting over I'd get the roller cam shortblock from Performance Automotive Warehouse (PAW Inc) 1-818-678-3000. It's on pg 61 of their catalog.

For $1750 you get a SHORTBLOCK with...
"A new GM standard bore 4-bolt main iron block with 1-piece rear main seal. Honed for Moly rings. Painted inside with rustoleum. Outside of block is painted with your choice of factory colors. Fitted with new cam bearings and brass freeze plugs. Kit includes new aluminum rear main seal retainer kit. Cast iron 1-piece rear main seal crankshaft custom ground on rod and main journals. Micro-polished w/oil holes chamfered. Factory forged rods that have been shot-peened, resized, fitted with new chrome moly rod bolts. New Federal Mogul anti-friction coated hypereutectic pistons. Flat top piston with 67cc head will give approx 9.0:1 compression. Optional forged flat tops add $184. New Moly faced top compression ring w/premium stainless oil ring. New Clevite M77 Tri-metal bearings to match crankshaft. New stock hydraulic roller camshaft. Crane's Compucam & Comp Cams hyd roller cams available. Phone for prices. New PAW single roller chain & gears. Assembly custom balanced with pistons fitted to rods."

There is a longblock available for $2450 but it has World Products S/R (Stock Replacement) cylinder heads with 1.94"/1.50" valves. I'd get different heads if you're going to go thru all this trouble. Otherwise the longblock includes new hyd roller lifters, OEM replacement pushrods, a high volume oil pump, a full gasket set, and new PAW factory replacement rocker arms (self-aligning).

This would have to be shipped by truck so add roughly $100 to the price. Since all this stuff is new there is no core charge.

Anyway if you bought the forged pistons ($184) and substituted AFR heads (+$800?) and a double roller timing chain ($40) you'd end up spending $3400, same as the ZZ4 but you'd have better cylinder heads, connecting rods, and pistons.

CorvetteZ51Racer

True, you do end up with a motor with better heads, etc, but you also end up with a motor with a cast crank instead of forged.

For $200 more (if you want to buy a shortblock) you get the ZZ4 shortblock with the forged crank, but not cam or timing chain, which is good because the cam and timing chain they have in the PAW motor are weak. The cam is tiny, and I wouldn't put a single chain on any performance engine, especially if you're going to rev the motor.

Personally, I still go by the theory that the best way to get a new motor is to build it yourself from the ground up if you have the expertise. If you don't, make friends with someone who does and buy a lot of beer :D

CorvetteZ51Racer

BTW, while we're talking crate motors and numbers, don't believe the posted power numbers for Scoggin Dickey's TPI crate motor. They either have a typo in there or are lying. They post power numbers of 357 hp and 416 lb-ft @ 4200 rpm, which is not possible. HP = TQ * RPM / 5252. You do the math...if it's making 416 lb-ft @ 4200, it's only making 332 HP @ 4200.

vetracer

I like the idea of buying the ZZ4 short block and putting good heads on it, too. What about the stock ZZ4 cam? Is 350 hp possible without other mods such as port matching the heads and intake, going high compression, etc? I could probably leave out roller rocker discussion, its been beat to death in other threads and it seems comp cams has some pretty good ones.

johnboy89

What about a 383 short block as opposed to the ZZ4?

CorvetteZ51Racer

If memory serves, the ZZ4 shortblock is a roller block. The fact that it's a 1 piece seal is also what makes me think that.

Honestly, if you combine a TPIS Miniram, AFR 190 heads, and a cam similar to the HotCam, you will be there. You could definitely go bigger than the HotCam with no problems on that combo and be totally fine, but I'd have to look at the flow chart for the 190s and find out what RPM you want peak power at before I could give you a better idea of what cam to use.

gtsyellow

my only gripe is the cost VS assembly. crate motors aren't built like the engines that come out of a good shop. bearing clearances aren't as tight and the balance isn't as exact. the price is also similar these days. even the parts quality isn't as high. hyperutectic pistons and PM rods are probably fine to drag race and make 450hp but i wouldn't go road racing or shoot any n02 on it. big cams and high rpms also shake them silly.

jmr302

The nice thing about the PAW offering is that you can substitute whatever cam you want. I'm assuming you could also sub in a better timing chain or even a forged crank if you feel you gotta have that.

CorvetteZ51Racer

FWIW, I wouldn't use PM rods in anything over ~350-400 hp, whether it's drag racing or not.

merrick

It is probably peak 357 HP, but not at the same RPM as the peak TQ

vetracer

Who makes the hotcam? what lift and duration? Should I go 1.6 roller rockers? Remember my parameters: I will be using the TPI setup pictured at the top of this post, not the miniram. Also keep in mind my performance goal: 350+ horsepower in a street car that will never be raced or really abused. My target budget is about $5,000.00 for the long block only, not including the intake or valve covers. :auto:

Chief Muktar

GMPP makes the hotcam, it was made for showroom racing of the LT4 motor. lift is .525/.525 with 1.6 RR, duration is 218/228 @ .050 and LSA is 112

NavyVet

gtsyellow - thanks, I was unaware. Paul

CorvetteZ51Racer

My point was that they list that the motor is making 357 HP @ 4200 rpm. Since they also happen to list the torque output at that rpm, you can check their math...it doesn't work out.