tcrisp

GM 350 290HP Deluxe Engine could this be use for a 350 tpi engine .

sofakingdom

iTrader: (1)

It's a 165 HP 70s smogger turd with a slightly bigger cam in it.

Not a good choice.

The ZZ4 is a Vette L98 (same power level as a F-body L98 exc w aluminum heads) and a different cam. If you want to approximately duplicate what you've got (or would have had if it had been a 350 instead of a 305), that would be a better choice.

That other thing is a SERIOUS downgrade.

spurgeon76

You could use it, but it is not a hyd roller cam and the Compression ratio is like 8.5 at best. with a cam and head upgrade you could make some decent power. I would look for a l31 shortblock http://www.skipwhiteperformance.com/....aspx?Item=L31 and add the heads an cam of your choice.

Damon

In stock replacement/mild upgrade situations I've used the base version of that engine- the regular old Targetmaster 350 (rated ~250HP). It's DIRT cheap. Bascially it's the 290HP engine you're looking at but with a milder cam. (Personally, I would never use the GMPP 290HP engine- too much cam, too low a compression and crappy heads = pig.)

It doesn't sound like much of an upgrade but it'll still blow any stock 305 into the weeds. Your stock TPI setup will bolt right onto it, it has an exhaust crossover (so your stock EGR system will work) and it's got all the bolt holes you need to mount everything up like the front end accessories. Plus it's mild enough your stock chip and injectors will run it acceptably (earlier MAF TPI systems are more forgiving of engine changes than later speed/density systems).

Agreed the ZZ4 would be a heluva upgrade from a stock 305, but it's pricey and you will definitely need bigger injectors and custom programming to run it (including turning off the EGR system in the chip, since the heads have no provision for the exhaust crossover)

MMroc86

This engine gets brought up very often and everytime it is frowned upon....

The l31 is much better and not much more. Do a search for l31 vortec, you'll find a ton of great info the engine....

I will personally be upgrading to one in Feb.

Jegs,summit and scoggin dickeys all sale the longblock with the vortec heads.....

afremont

Let's see $4000 for a 1996 tech motor that could still benefit from new heads, and intake and even a cam or $2000 for pretty much the same thing with vortec heads and a milder cam. I agree with you, the L31 looks to be a much better deal and leaves me $2000 to play with.

EDIT: I see you get better pistons with the ZZ4, but the same rods. You also get the lame intake, dizzy and a water pump. I still don't think that worth double the price and then some.

EDIT2: Here is a good article showing just how much hype GM adds to the ZZ4. It's baseline performance was no where near what GM claimed. Some new heads and a cam fixed all that, but new heads are expensive.
http://www.hotrod.com/techarticles/e...s/viewall.html

Damon

In general, GMs crate motor ratings are some of the most honest around. Not that they can't turn out a clunker every now and then, but I don't recall mass internet protests from disappointed ZZ4 owners.

Also I should point out, you couldn't bolt a TPI intake up to a set of Vortec heads without a pricey (~$400) TPI lower intake (plus the necessary chip reprogramming).

And both motors are later one piece rear main seal blocks, so a new flexplate/flywheel would be required with either choice.

That's why I mentioned the ultimate low-buck choice of the 250HP Targetmaster 350 (About $1500 for the entire long block). Everything will transfer over from your existing 305 and the stock programming will still run it acceptably. It's no power house, but it'll run stronger than your original 305 did even when it was new and it comes with a warranty.

afremont

I hear ya, but I don't see allot of people dynoing 245rwhp and 345ftlb with stock L98 motors. It seems to take some work (quite a bit in some cases) to get the rated performance out of these cars. Just sayin'

EDIT: The targetmaster is what it is. It's cheap and with some upgrades it can make reasonable power. I just think that GM needs to back off on the price of the ZZ4 now that they are antique tech. My comments were more of a comparison between the ZZ4 and the L31. Sorry to be off topic there.

InfernalVortex

iTrader: (4)

Those who dont understand it owe it to themselves to learn the differences between SAE net, SAE gross, and rear wheel horsepower, because all give different numbers.

A lot of crate engines today are measured in "gross" horsepower, with giant headers and free flowing intakes where they dont have to turn any power steering, water pumps, alternators, or anything.

And some other ones are measured in "net" power. Our cars were measured in net power stock. So thats why it takes a lot to get an L98 to put down 245hp, because that number is measured at the crankshaft, not the rear wheels.

Anyway, the goodwrench motor is clearly measured in some form of extremely idealistic SAE gross power, because its nowhere near that range. Its as garbage as garbage can get. It's for, as sofa likes to put it, phone company vans. Thats about it.


Goodwrench 350 crate engine:
http://www.jegs.com/p/Chevrolet-Perf...52506/10002/-1


Vortec longblock crate engine:
http://www.jegs.com/p/Chevrolet-Perf...13788/10002/-1


I personally have noticed some weird semantics discrepancies with the Vortec and LT1 motors, as both are often listed as "externally balanced" when Im pretty sure they are not. There's a weird issue there, but we can break both of these engines down into the elements that make power.

Both are 350 cubic inches

Goodwrench 350: $1499
smogger flat tappet cam
smogger low compression heads that flow like crap
2 piece rear main crankshaft
4-bolt main

Vortec 350: $1979
lame roller cam, still twice as good as the super lame flat tappet of the goodwrench
The best Gen I smallblock iron heads you can get from the factory
1 piece rear main crankshaft
2-bolt main


So the vortec 350 has 2 less main bolts and costs $500 more - it's worth it. Just for the roller camshaft alone it's worth it, having the vortec heads is icing on the cake. The crazy thing is that somehow the goodwrench 350 is 260hp, but hte vortec 350 is 255. I guarantee you a real world SAE net hp number for that goodwrench 350 is going to be closer to the 170hp range than the 250 range. It's going to be WAY down on power. The vortec heads are never going to make enough power to need 4-bolt mains or splayed 4-bolt mains. The smogger heads DEFINITELY wont. 4 bolt mains are the most overrated "feature" of a block, they do NOTHING for power, and by the time 2 bolt mains are a limitation, you're way better off with a splayed aftermarket 4-bolt setup than any factory 4-bolt block.

And the Vortec long block is, IMO, a way better deal than a ZZ4.

Depends on your definition of reasonable power. To do anything reasonable with it you need to replace the pistons, because those are going to keep the compression ratio low no matter what heads you put on it. It costs a LOT of money to make the goodwrench 350 competitive. Dont even think about trying to put a roller cam in it. It will set you back $700+ after it's all said and done. When you can throw a $200 LT4 hotcam and some $60 LS3 beehive springs (with $60 retainers) into the Vortec crate and make 350 SAE net horsepower, a 100hp improvement over stock. And a 350 with 113 heads (zz4) is going to have a hard time competing with a hotcammed vortec 350. The zz4 probably makes closer to 300hp than 350.

350hp for $2250 vs
170hp for $1500

The only big drawback for the vortec 350 is the Vortec TPI base is quite pricy.

sofakingdom

iTrader: (1)

But of course, don't forget that the OP has TPI; meaning, it CHOKES any 350 to begin with, and then needs a $$pecial$$ baseplate so it can choke a Vortec 350 even worse.

I listed the ZZ4 nerely as being the "closest equivalent" to a TPI 350 that one can get from GM, not as "A Good Idea". I strongly agree, at this time it's NOT a good deal; even though at one time, it was the best they had.

Frankly, the best idea of all would be, get rid of the TPI, NO MATTER WHAT long block goes in there. A HSR, MiniRam, etc. will STOMP a TPI like Ndamukong Suh stomped that other player a few weeks ago and then finish the job by kicking it in the family jewels like he did this past week.

afremont

OK, I was under the impression that the 1990 claimed 245hp for an L98 was at the rear wheel and not at the crank. I was further confused because I have seen some noise about L98 equipped cars with the 3.45 gears (which you couldn't get in 1990 on an f-body) having a rating of 250hp. This further led me to believe that power was being measured at the wheel.

The L31 seems like the best bang for the buck since it comes with vortec heads and flat tops. The extra $400 for a TPI vortec base is well worth it compared to spending more than $4k for the ZZ4. In my opinion anyway.

EDIT: Oh yeah, you get a roller cam setup with the L31 too. I never really looked at that motor before, I'm glad this discussion came up. I apparently thought more of the goodwrench motors than they deserved.

sofakingdom

iTrader: (1)

The HP "ratings" from the mfrs are for crank HP, NET, with the motor "as installed" in the chassis: full exhaust, production air cleaner, production tune, all "accessories" (emissions control devices) installed and operating, assembled as produced (WP, alt, etc.).

No engine, not the L98 or any other, is "rated" at the wheels.

The difference between an engine "rated" at 245 HP and at 250 HP is negligible. There's SO MUCH variation from one individual motor to another, the distributions for their ACTUAL OUTPUT would overlap substantially.

AFAIK there NEVER WERE any 350s available with the 3.45 gear. That came ONLY with 305/5-spd, and ONLY those w G92. 350s w G92 came with 3.23 or 3.27 depending on whether they used a 10-bolt or a 9-bolt that year, otherwise 2.73.

afremont

I feel dumb now, but I sure thought they were rear wheel ratings. I mean I'm aware of the gross/net changes and some other things thru the years, though some of them came in around 1996 so I wonder how that affects our cars ratings. It appears that they didn't bother with upping the rated power on the non air-conditioned 1LE cars or the dual cat N10 cars. Those things should have been good for a 5hp increase, at least the non ac option.

I was just assuming and u know how that goes. Glad I know now because I was thinking of getting my car dyno tested and I would have been extremely disappointed in the numbers I'm sure. So if I'm lucky I should be looking at roughly 200rwhp for my low mileage 1990 L98? Does that sound right?

I looked at a couple google things on the L98 245hp vs 250hp "mystery". Looks like it might have only been on certain corvettes. I agree that the distinction is irrelevant in the real world since production variations would blur the tiny gap.

sofakingdom

iTrader: (1)

No; nothing changed any time around 1996.

Right: 200 rwhp measured is (was) real typical for totally showroom bone stock L98s. S/D ones might do 210ish, irrespective of any "ratings", especially if running higher heat-content gasoline (regular instead of premium).

AC doesn't materially affect the HP "ratings". The N10 option that was part of the G92 package should have though, hard to say why they didn't invent a different number to go with that.

IMO people put entirely too much faith in those "ratings"... having lived through the changeover from gross to net, and seeing some of the malarkey that went on especially back then, I've NEVER put even a dust speck of salt worth of trust in those, let alone a grain. As far as I'm concerned that's all just marketing bishop-buffing, with random numbers pulled out of where the sun never shines, to make great ad copy. Designed to be in the video right behind the serious-sounding male announcer gravely intoning <air monkey gif> ".... most innovative {fill in the blank} we've ever made!". </air monkey>

afremont

Oops, yeah looks like 2006 was a change to "certified" hp, not 96. An AC unit uses right about 5hp so that's why I was thinking.... Maybe it's not a "standard accessory".

sofakingdom

iTrader: (1)

Right: when the fine print describes "all accessories installed and operating", they're not talking about power seats and stereos and A/C; they are referring to emissions. They don't turn the A/C on "High", operate the wipers and headlights and power windows, and all that, to generate those "ratings".

With the A/C not running, there's well under 1HP of parasitic drain, so it's not material to the "ratings" "process". (I use the word "process" loosely, please pardon me)

Not sure what "certified" HP is; as far as I'm aware they don't "measure" it with a dyno or anything, since that would clearly be .... aaahhhh ... impractical ..... at best. Probably just means, they guarantee that all individual cars will make within some % of that. Truth-in-advertising regulation is steadily catching up with the BS.

Now if they can just do the same with the gas mileage "ratings".... which are EVEN MORE bogus than the HP ones, if that can be believed. Most car mfrs are so brazen about that, that they include a routine in the firmware that detects the "EPA driving schedule", and if it sees that, puts itself into a special "mode" to generate those impossibly meaningless numbers that they publish. But even THAT isn't good enough for some of the mfrs; the Koreans got caught ouright FALSIFYING theirs a few weeks ago.

http://www.latimes.com/business/auto...,6756011.story

Just think, if they're willing to completely bogosify REGULATED numbers like THAT, what depths will they plumb regarding pure marketing hype like HP?

Damon

Sofa- you gotta give those government types some time to get the ratings really dialed in. 4 decades and counting! They're closer to reality now than they used to be, but I'm sure there's still some monkey business going on. They'll get it right about the time gasoline burning engines are outlawed and we all drive electric cars. Then they'll just monkey with KW ratings of the motors and battery life expectations!

vetteoz

iTrader: (13)

The superior potential Vortec HSR complete with fuel rails ( non adj reg )
http://www.jegs.com/i/Weiand/925/7542/10002/-1
http://www.jegs.com/i/Holley/510/534-185/10002/-1

is less than a $100 more than the Edelbrock #3817 Vortec TPI base required to run the stock TPI
http://www.jegs.com/i/Edelbrock/350/3817/10002/-1

whoaru99

The problem with ratings is that yes, some may be bogus, but regardless of that you'll never get the "rated" number unless you know exactly the test conditions that produced the rating, then repeat the test using the same test conditions.

MMroc86

Stealthram is the best way to go if you get the L31, the baseplate for your TPI is to $$$ & lets face it, TPI far from the best thing ever invented. One of the downsides is that you'll have to remove the emblem from the back of your car that says 5.7 tuned port injection!

The ZZ4 seems like a ripoff. From what I've heard and read its a good reliable engine, its just grossly overpriced.

If your going to pay that much, you may as well go with a 383 & make some SERIOUS power.

-AO-

I bought a new L31 in May when they were on sale. It was $1920 shipped to my house. With 1.6 RR's and a 600 carb, it ran a 13.0 @ 105 on a hot Summer day. I sold the slightly used Vortec heads for $380 and bought the Dart SHP 180cc 64cc heads. I put some 1.65 RR's on. It now has a 700 cfm TBI unit and I think it should run mid 12's. Yes it still has the stock roller cam. The timing cover and oil pan have never been removed. I'm using NGK TR55 plugs. What spark plugs are yall using?

dimented24x7

iTrader: (2)

The shortblock is good on those GMPP 350's, but the heads suck, and the cam is too big, as already mentioned. They used to sell the shortblock seperately for that engine for about $700. Came machined for and included bi-metal aluminum bearings (I tossed all the clemex in the trash in favor of King EB's race bearings), had PM rods, 4-bolt mains, which made it a great deal. But, the flat tappet cam is a huge drawback for performance. The 12 cc dished pistons dont help much either. The thing with the flat tappes is that the larger XE type cams everyone likes to use need heavier springs to work properly, but the heavy sping makes them have a very short life on the street. I converted mine to a roller, but in hind sight, just buying a roller block up front is a much better deal. The engine isn't that attractive if your buying the whole thing with the 50 lb. boat anchors attached to the top of it and a crummy flat tappet cam and stock valvetrain.

sofakingdom

iTrader: (1)

Sounds great on paper; the only problem is, THERE ARE NO SUCH CONDITIONS, unless you count "smoke-filled room with locked door, no engines, no engineers, and no testing" as a "condition". They're pure made-up, plucked from Millenium Year Application Software System (MYASS) marketing hype, that only have to be just barely not false enough to get sued over. "Maintain plausible deniability".

1gary

Guilty.I confess.I was me as one of those guys fudging the numbers in a smoke full room for GM Chevy. But I will never tell ya what we where smoking.......................

sofakingdom

iTrader: (1)

Hey, don't ask, don't tell; eh??

dimented24x7

iTrader: (2)

The ratings now are actually overseen by the SAE, with an inspector being sent to witness how they do the tests. Doesn't mean they dont cheat, but at least the engines are now run on the dyno with the stock accessories and exhaust as they would be on the car to give more realistic numbers that seem much more in line with actual performance on the street after you drive it off the showroom floor.

InfernalVortex

iTrader: (4)

They are now. The Goodwrench 350 HAD to have been grandfathered in.

Theres NO way a Goodwrench 350 with low compression, crappy flat tappet cam, and terrible heads makes 5 more horsepower than a stock L31.

http://www.jegs.com/p/Chevrolet-Perf...13788/10002/-1

http://www.jegs.com/p/Chevrolet-Perf...52506/10002/-1

Pretty obvious that the playing field here isnt really level.

afremont

Look at the duration on the cam on the L31, talk about choking a motor off. People make fun of the "smog" motors with dish pistons and big chambered heads, but those engines could still make power. I know, I had one in a '75 Impala that would eat BMW 5 series cars alive from light to light back in the late 90's. All it had was an Erson TQ20 advanced an extra 4*, a stock two barrel smog carb, egr, single 2.5" exhaust behind a hi-flow cat and stock manifolds, intake and heads. The car weighed 4500lbs and ran the stock hiway gears. It would just bake the tires and launched almost as good as the Iroc. The tranny was built by Circle-D and ran a "stock" convertor that they built. It was a complete dog before the cam and exhaust upgrade. I probably had more fun with that car than any other. It was fugly and beat up, but it embarrassed allot of people.

InfernalVortex

iTrader: (4)

Certainly...

L31 roller cam:
191/196@ .050 .414/.428

LB9 cam ('85 Flat tappet)
202/206 .403/.415

Goodwrench 350 flat tapet cam:
195/202 .390/.410


Theres really not much difference there. Remember hte L31 cam is a ROLLER cam, it will make more power than a similarly sized flat tappet.

You think 4-6 degrees more duration and less lift will outperform an engine with FAR superior heads, far superior camshaft technology, and a far superior compression ratio? 4-6 degrees duration is almost nothing.

1985 TPI 305 got this cam:

202/206 .403/.415
- 215hp

1986 TPI 305 got this cam:

305 AT
178/194 .350/.385
- 190hp

A full 24 degrees less duration and .050 less lift on the intake side and it only made 25hp less, and the bigger cam here isnt even a roller cam. Yet somehow 4-6 degrees of duration (the ONLY advantage the goodwrench 350 has over the L31) makes up for a whole engine full of smogger garbage and makes 5 more horsepower? Just not a plausible explanation. The L31 must be measured SAE net, and the goodwrench 350 is the old SAE gross power rating. And that fits what we already know about these engines. The goodwrench 350 is a 175hp smogger at best, while the vortec 350 makes 250 easy.

afremont

Wow, you're right there's not a whole lot of difference there. I admit, I didn't see the duration on the goodwrench motor, so I gave GM the benefit of the doubt and figured they ran more than what you show there. I still say the L31 cam is choking the motor, it's just that the others are as well.

So you think they're way under rating the L31; to what end? I can't believe they'd out and out lie just to sell more goodwrench motors. Surely both of these motors have been dyno'd by the magazines. They can't be massively over rating the goodwrench motor or there would be mass screaming by now. So why would they under rate the L31?

InfernalVortex

iTrader: (4)

1gary and sofa etc would probably be able to give you a much better answer than me, they've been at this a lot LOT longer than I have. However like I said, my theory is that the L31 is a factory replacement engine for a specific vehicle that was rated at 255 SAE net power and was built LONG after SAE net became standard.

The Goodwrench 350 has been around lord knows how long.... probably the mid 70's, this is where the more experienced guys would have a better idea, but I imagine back then they must not have been strict on crate engine performance figures. And they may not even be strict on it today, and the Goodwrench 350 was measured the old "SAE gross" style, which is pretty close to Sofa's rendition of a smoke filled bathroom stall full of constipated engineers. It means nearly nothing in the real world. The goodwrench 350 may be a factory production replacement engine, but Im not sure. I know it's got 70s factory smogger era garbage in it, but Im not sure if it exactly correlates with a particular production engine. It's probably more of a "any work truck/van/station wagon with a 350" universal engine that will get you back to hauling manure/carpet cleaning supplies etc like before. That's at least how GM treats it and promotes it. A budget v8 to get you back to work. The power rating is (my theory) a carryover from SAE gross power rating days when they either werent strict about it, or it's not subject to SAE net standards because of how old its intended vehicles are or crate standards or whatever. Any other company's crate engines are likely rated a rough equivalent of SAE gross too. (Blueprint etc)

The L31 crate is exactly an L31. It's a factory repalcement engine for a specific vehicle and that vehicle was rated at exactly what the L31 makes. And I think that's why it has the "official" rating it does. If it was measured the same kind of SAE gross it'd probably be in the 300-350hp range, and that may or may not upset some EPA people, or some warranty replacement regulations, or some SAE standard, or California, or whatever. You never know what beaurocratic red tape you're going to cross over when it comes to these newer fuel injected, emission controlled setups. So it's probably some sort of covering of their rear ends they do not to scare off the people that need a stock replacement truck engine for their 96-98 truck so they, too, can get back to work. If they know their truck is 255hp and they see this engine thats 350hp... they may end up going after that crappy goodwrench 350 instead because it's cheaper and matches what they think they're supposed to have better, even though it's incorrect.

So it's probably some obscure regulation or marketing reason or grandfathering in or somethign, I dont know why but I can sure speculate. But what i do know is that there is no way that Goodwrench 350 makes 5 more horsepower in a vehicle than the Vortec 350 does.

I also think GM probably makes a ton of money churning out those goodwrench 350's. The people who buy them generally just believe the advertised hp numbers and they're happy, or they dont care about performance at all. The vortec 350 is quite a deal at less than $2k, and I doubt the margins on it are nearly as high.

To further complicate things, for reasons of more impressive numbers, and also probably less so for more consistency across different articles/tests, the magazine articles generally rate engines in the "SAE gross" method also. This eliminates variables like water pumps and alternators and power steering pumps and exhaust manifold discrepancies from different vehicles, and allows you to evaluate the engine just by itself. That is good, but the numbers the magazines get are not realistic when the engine is put into a car. They're good for comparing one cam to another, or one cylinder head to another, and making relative comparisons. But not so much for making real world flywheel horsepower predictions. This is why there are people who keep think you can build a 400hp 305 just because the magazine article did it. That magazine's 400hp 305 would be lucky to make 300 in the real world, and it probably wouldnt be all that streetable either.

86LG4Bird

iTrader: (1)

I'll add some more info for this discussion, since I DO actually have some experience with that L31 cam. Trust me, it's not a slouch by any means.

In my 98 L31 pickup with no more than LT headers, single 3" exhaust, and a PCMforLess 87 octane tune, I dyno'd 254 SAE rwhp @ 4500 rpm through a Vig 3000 stall converter unlocked. That calculates to about 310 hp at the crank (old style gross hp).
Furthermore, that identical cam in my LT1 Impala with 1.6 rockers and stock heads (same ports and valves as L31 heads) dyno'd 305 SAE rwhp @ 5150 rpm through 1-5/8 Tri-Y headers, uncorked, same TC. That's 372 at the crank See what a good intake manifold versus the POS L31 manifold does for you?

And no, those were not "happy" dynos. Dragstrip mph vs. weight with both vehicles back up the numbers.

joshc

iTrader: (1)

Don't forget there are 2 economy GM crate 350's
10067353 base 350
Rated at 260 hp with headers and aftermarket intake and carb
only rated at 195 hp with stock carb, intake and exhaust manifolds.

then there is 12499529
This is the engine the op is referring to.
it is the same short block and heads as the base motor but with a much better cam.
They rate this engine at 290 hp , but as I understand it, that is rated with headers and an aftermarket intake and carb.

Chevy High Performance magazine did a dyno test on the base 195hp 350 several years ago. With stock manifolds carb and intake it actually made 239 hp on the dyno!
They threw on headers and an edlebrock intake and hp was 265.
Check out the articles, they ran it in 5 or 6 parts total after different levels of modification.
http://www.chevyhiperformance.com/te...d/viewall.html

joshc

iTrader: (1)

BTW, if you aren't afraid of getting your hands dirty and have some mechanical ability, you can save alot of money by buying the 260 hp motor and swapping in a better cam.
You can buy the 260hp engine for $1399
Comp cams 268h $123 on ebay
For $1522 You would have and engine that would out perform the $2049 290hp motor!

InfernalVortex

iTrader: (4)

The 290hp one still has the same garbage compression ratio and cylinder heads. The cam is also crappy and primitive by todays standards. Id take a factory roller cam any day. At least a more modern grind like the xtreme energy cams or the voodoo cams if youre actually willing to run a flat tappet these days.

A Vortec L31 with beehive springs and XR276 will make nearly 400hp. $2500. Cant beat that unless you find a pullout LT1 and give it the same treatment.

dimented24x7

iTrader: (2)

The SAE ratings only cover factory cars. AFAIK, theres no requirement for aftermarket components like crate engines unless they where used in production vehicles. WYSINWYG with something like a Blueprint or GMPP engine.

My comment was just to point out that factory ratings can now be trusted, unlike in the past.

dimented24x7

iTrader: (2)

With the changing oil formulations and higher spring pressures needed for those grinds, they're simply not reliable. Flat tappets are VERY sensitive to spring pressure. Id stick with a factory roller block.

dimented24x7

iTrader: (2)

The Goodwrench 350 is intended as an OEM replacement for pre-86 vehicles.Its changed a bit through the years. It has something like 8.2:1 compression from my calculations with the 12 cc dish and 72 cc heads. When I put mine in way back when, it was barely any different from the L03, other than it made all of its torque at 2000 RPM, peak power was at 3000 RPM, and then it would roll over and take a nap. Really pathetic engine. Shortblock is like the L31 with PM rods and nodular cast crank thats machined to tighter tolerances than the earlier engines they used to make as they now use bi-metal aluminum bearings. As said, it also has 4-bolt mains, which is nice, but not needed. Probably more for a selling point than anything else. If you swap out the junk on it for good parts, it will happily buzz to 6k+ and make really good power.

Heres mine with trickflow heads and an XE roller:


In hind sight, though, that cheap $700 shortblock rapidly became lots of red ink when it came time to buying the right parts to make it go.

1gary

Now that is a excellent write up.Well said.

1gary

I am going to tell you guys once more.There isn't one glossy magazine out there with enough of a spine that is going to give a poor review in any test of it's advertisers.Their sole purpose is to sell parts.Period.So all the link ref's to Car Craft,Hot Rod,Popular Hot Rodding,Chevy High performance, and alike you can just throw them out like bad garbage.In fact I wish forums like this one would ban them altogether.I'm not 100% sure,but I think Yellow Bullet has.Those articles are poplar,but their worth is entrainment value only.That would mean the infor provided would be on the strength of the forum members.Here there is plenty of that around.

Yrs ago the concept of a crate anything meant something.GM was a for-runner in that market.I believe after taking apart some of those "crate" engines you are far ahead to build your own in what end product you get.If you insist on a new block to start with, fine.Just be prepared to be nickel/dime on all the parts needed to complete it.It is GM's will to force the market into a crate engines where the margin is better.

Trust me,I am not a flag waving American.I look at things that have come through our engine building business and if a source is better quality and the source is got a clean record in the business side,then it is.I can tell you that GM's Mexican crate engines are poor at best.I know well the range on the clearances of production engines from working at a Chevy engine plant.Those where/are far from race ready expectations.I am not talking when I speak about race ready specs in these crate engines,nor am I talking about high performance specs,nor am I talking about mere replacement engine specs,what I am saying is a lowest of low dollar shade-tree dollar source engines in those specs and parts.Can it get any worst??. Well after GM created this concept of "crate engines" name,everyone and his brother jumped on that concept naming what they sold as a crate engine.Some never building themselves a damm thing,just farming it out to the lowest bidder.Question.How many as Summit crate engines do you honestly think they build??. And we could go through a list of sources where logical deduction should come to the same conclusion.QC controls??. Well you can see where I am going with this,right??. What meant something before to buy a covenant crate engine or short block is no more. Those purchases still need to be taken apart,cleaned,and have all the specs double checked.I know you all will be resisted to what I am saying here,but I am a person who have been very fortunate to have a business and the background at GM to have exposed me to all too many engines and situations.I like to think of myself as a straight shooter and I am just trying to help by having people well grounded in the facts.And if you bought one those crates and took it apart and it's all good,rest easy in that fact.You got lucky.

The ratings??. Yeah,you guys I think have that well covered.Just don't take what is offered at face value.

-AO-

I did my research before buying an engine, and like I said, I'm happy with what I did.

L31 crate eninge for $1900. Sold Vortec heads. Bought Dart aluminum SHP heads for $930. Bought highest lift rockers available, which were 1.65's for $250. And the engine doesn't leak any oil because I never had to remove the oil pan or timing cover.

1gary

It's a chicken or egg question.No way I'm I defending companies who cut corners,but if not for a profit,there isn't a business.Consumers pressure to constantly want to go fast,but don't want to pay for it is the end result you are seeing.When I see posts of guys that want to spend $1,000 and want 500 rear wheel hp,it is almost laughable.Forces honest guys on this forum to post negative posts to a O/P's goals to get them to face reality.Forces businesses to sell,well for the lack of a better term,junk.
If some of you didn't see my other post in another thread.If that is your thinking,wrap you head around this.You have two choices.Open up your thinking on a build to a goal that your going to acquire the reliable parts over time and add up the costs at the end of the build.

OR:Sell everything you got.Car,parts,tools,equipment,everything.Walk away totally from hot rodding.It is very likely you won't finish what you started anyways.Then:

GO BOWLING.IT TAKES A BALL AND SHOES AND YOUR ALL SET!!!!. BEST PART IS THREE STRIKES IS A GOOD THING.

dimented24x7

iTrader: (2)

Well, as the old saying goes, you get what you pay for. The 290 HP GMPP engine isn't junk per se. But it goes without saying that by the time it goes between the fenders, it will make about 220 HP. Buyer beware.

At any rate, given that the OP didnt post again, this looks like a trolling dump and run for some entertaining posts thats run its course.