sharkthehunter77

The ZZ4 topic really sprung to life and it got me thinking about using the stock block on the smogg motors as a starting point, i bet by the time U got the engine built up you'd spent as much as for crate engine but i am curious about hp/tq numbers. The ZZ4 "cloners" got me thinking about this idea. Several of U got the ZZ4 crare motor and got very good numbers with minor mods. Any late shark drivers got similair or better numbers working withg the stock block?

68shark

Motorhead has a nicely built L48 in probably the nicest '80 you'll find. It was built by the guys on the TV show Dream Car Garage, Legendary Motor Cars located just west of Toronto. At our Toronto area dyno session last July, he pulled 280rwhp with 320rwtq. Those numbers are from memory, so hope Motorhead chimes in to confirm. He has recently added NOS, so obviously those numbers weren't good enough!! :cheers:

SanDiegoPaul

Any late shark drivers got similair or better numbers working withg the stock block?
I retained the OEM L-48 in it's entirety ... but I did use a Chevy block though it's a 4-bolt main one. I should have it on the Dyno this week after getting some carburetor ghosts worked out.

docmow

do you think my stock 180 hp counts i did not think so
docmow

SuperFast80

Actually, I think he pulled 285-290. :thumbs:

J75

Not sure the amount of mods you are speeking of,but there are a few forum members[ my self also] who built 383s from L48s.Mine was 428 fwhp and it has a fairly mild cam. It is easy to get 300-310 fwhp using a quality rebuild kit with 9.0 com. and a good cam and intake.The main point is it does not matter if it is an L48,L82 or an LT1.It is still a 350 sbc and will respond to all the same mods. :chevy

Ganey

Exactly.

MANY have been built w/ much more HP than the crate motors!

MotorHead

Yup, 285 RWHP and 327 RWT, not bad for a 195 HP (net ) smog motor. It crapped out at 5000RPM, since then I have added a complete MSD igintion.

I willl take it to the chassis dyno this spring with a 150HP shot and will be shooting for 400 RWHP, yee ha :D

I guess I should say 400RWHP or bust :lol:


[Modified by MotorHead, 10:34 AM 1/2/2003]

sharkthehunter77

correct me if i'm wrong but horsepower and torque comes from the pistons, cams and heads as well as a well tuned fuel delivery system. If thats the truth then adding top of the line versions of these items plus eliminating the restrictive emmissions gear should add quite a horepower/torque boost. I am using the two threads i created to get an idea of cost/horsepower ratio of crate VS rebuilt L48 (in ZZ4 clone guise). What i have learned from you guys sofar is that, yes, the L48 has potential to be good performance engine as long as performance is defined as 300 or so ponies to the rears. I have seen no L48's on the forum with much more and wonder if those guys did not spring for the iron heads? forged psitons or live in a state with were they cant utilize true dual exhuast. I have true dual exhuast/ performer manifold and will settle for the comp cam 260H and set of headers and would like to see more then 300 ponies at the rears. However, i am beginning to see that a set of new/used iron heads or new manifold will be neccessary to get me passed the 300 mark,...is this a good assumption?

MotorHead

Believe it or not 300HP at the rear wheels is a lofty goal for a small block ( for a street motor). I know reading the threads here about 400 500 and 600 HP motors it doesn't seem like much but believe me if everyone actually dynoed thier cars at the rear wheels there would be some suprised Vette owners.

There were three ZZ4's dynoed the day I got mine done and all came in with less HP at the rear wheels( granted one was not running too well at all ), that being said I probably spent just as much, if not more on mine than the crate engines. As for iron heads, you can get 550 - 600 HP out of Sportsman II heads.

To try and answer your question, to get 300HP at the rear wheels, and have a streetable, fun to dirve car you need all the aftermarket has to offer in heads intake,cam, exhaust and carburetor.




[Modified by MotorHead, 5:18 PM 1/2/2003]

1979toy

I've got about 250 horsepower at the rear wheels estimated by my quarter mile times. My short block is a standard L48 with the mods shown in my sig.

'79ProwlerOrange

the only reason i wouldnt mod an L48 is the lack of 4 bolt mains. i know it dosent matter until higher horsepower, forced induction, or big nos #s, and if you set eveything up right then 2-bolts can take it no problem. just a mental thing though.

sharkthehunter77

I most certainly believe 300 rear wheel ponies is lofty, and probably satisfying too. My goal is for a low 13's daily driver with power from low to mid-range. 300 rear wheel ponies is pobably more then enough. I hope the comp cam 260H will do this as its only $200, if not then its time to look into iron heads which would put me at about $1400 in mods which is still much less then a crate engine. My purpose is to utilize the experience on the forum to the maximum extent. That way if i deploy, ( i'm Navy) and leave my car with Ron's hotrod shop with a list of mods to make based on the advise and experience of you guys i know i will be happy with the cars performance when I return a few months later.

nunus79

Shark,
I see you accepted some of the things I mentioned in previous posts. Just want to clarify a couple of things.

1. With everything being the same, yes, an iron head is supposed to make more power than an aluminum head. However, with an aluminum head you can run higher compression and thus make more power than a lower compression iron-headed engine. So, if you are planning on changing pistons, you might as well change to higher compression pistons and use aluminum heads. If you are slapping on heads on the stock low compression L48, THEN you should look for iron heads.

2. Again, if you are going to change pistons and run increased compression, the Comp Cams 260H may not be the best match. If you are not going to do too much more modifications (pistons), then the 260H would be a good choice.

300 rwhp will be easier obtained by rebuilding the short block and using aluminum heads with a more aggressive camshaft. Part of the ZZ4's power lies in the use of a roller camshaft.

sharkthehunter77

ah ha, so its the roller cam thats the missing ingredient that the ZZ4 crate offers!!!!
Thats deffinitly a big ticket item as far as cost is concerned. I doubt many people have the tech ability to convert and thus the crate engine solution ends up giving you a much better cost/horsepower ratio for your money based on that.I may have come across the wrong wy on the forum( easy to do on the internet). But its better to screw up your communication on the net then to do it before throwing down the VISA. I suspected that it was low compression pistons/heads/cam combo that made smogg engines "smogg" engines but was wondering why more vette owners just did'nt change the pistons/heads/cam for much bigger power, now i know! My being in the military and thus subject to transfer means the most cost effective thing to do for performance is go with the comp cam 260H and ( along with iron heads if i can find some used ones at a respectable price) leave the "smogg" engine compression where its at. I can just go the crate engine route once i hit the mainland. Now, the more dealings i have with the islands vette clubs the more i get the inside track on people who can build up my CSB ( with the aluminum heads and all) for a fair price, thats why i am taking my time and asking questions.

VetteNut72

There is also another advantage to a ZZ4 (or late model block) over a L48 and is a bigger deal than most will admit. It's called One Piece Rear Main Seal. Leaks at the two piece seal on older blocks was and is a continual problem which is why the General changed it. Put that together with roller cam capability and it's a no brainer. For about $500, you can start your rebuild using a fresh, new style block.

I'm not sure of the answer, but when you buy a crate motor from other than the General, do you get an old, bored two piece seal block or a fresh new style block? If the answer is old block then that is something to think about.