carbed LG4 to an L98 motor?

unbolt, remove, bolt? easy?

 

yeah it'd be a direct bolt in, only real problem you'd have is none of or very few of the ECM controls would work. if it's just a short block then there'd be no problems

 

L98 is the HO motor from 1984, right?


Thanks,

 

No, the L98 is the 5.7 TPI in 87-90 IROC's and 91-92 Z28's. They were all mated up with 700R4's because the factory couldn't warrant the t5 behind the torque of the L98. The L69 is what you are thinking of for the 84 model year. It was just a 5.0 and it's numbers are 190hp at 4800rpm, 240ft/lbs at 3200. The L98 was a bit higher and wasn't carbed with 230hp at 4400rpm and 330ft/lbs at 2800rpm....so substantially different engines
Lc

 

Oh ok, thanks. I always get the two RPOs confused.

 

but can i use the quadrajet on the l98? and do i need to have ECM controls? i don't have emissions here

 

Well yes, but I'm confused.


Do you have the COMPLETE TPI setup with the computer and everything? Or no? You just have the engine block?

If you just have the engine block, then yes. ALL the components from your LG4 will work on the L98 motor (except maybe the intake manifold, from what I understand they have different bolt locations).

However, you can get a replacement intake manifold.

If you don't want computer control, you can just go with a standard non CC carburetor, and an HEI non CC distributor.

 

yes, i would just be buying the block, no TPI

as well, i would probably be rebuilding it before i pop it in

my quadrajet is computer controlled i believe, '86 Z28 LG4

 

The LG4 computer controlled carb and ignition system will work just fine with the 350 L98 long block in there. The heads of the L98 will have a different bolt angle for the center two intake manifold bolts on each side, but elongating the manifold bolt holes will allow you to get around that.

Can't say as much for the exhaust, though. Replace it. All of it. With nothing that has any relationship whatsoever to LG4. Please. For your own good. Do yourself a favor here. And us.

Oh, the LG4 air cleaner is no good, either. Go for dual snorkel.

 

thanks

i was going to do engine first, then exhaust, then subframe connectors, and maybe in the future a roots blower.

i'm thinking of edelbrock TES and headers, with either a 3" catco or carsound cat

i was just quoted $575 CND (about $350 USD) for a dual snorkle, which IMO is very overpriced. i'm not sure what i'm going to do about that part

thanks

 

Some unsolicited advice: Do the subframe connectors first, then engine & exhaust at the same time.

You can make a dual snorkel. See the Tech Articles if you haven't see that yet. Something that can be done before the engine as well.

Any particular reason for the TES?

 

rp_guy,

I personally really like the TES. If you're on a tight budget, and want... I dunno.. 90% of the performance that you might gain with the Edelbrock TES, but don't feel like paying for 100% of the price. .. you can purchase the FLOWTech headers directly from J.C. Whitney. Very decent headers actually. They sell the complete kit shipped to your door for $200-$215 bucks. I ordered them a long time ago when I had a 1982 LG4 TransAm.

Made a huge difference in fuel economy and performance.

You have to call up their number and specifically order it if you want the whole kit with the Y-pipe.

If you want to keep the AIR injection fittings, you can also have them special ordered with the tubes installed as well. ALSO.. you can get them with the O2 sensor installed on one or both headers.

 

i remember reading somewhere that subframe c's should be done last, as they may interfere with the install of exhaust

i don't think i can find a left snorkle for dual

what is A.I.R. for? i don't have emissions here, so do i have to spend $100 more for it on the cat/headers?

 

If you are going to do things piecemeal, do the things that support increased power before you increase the power. But if you're worried about installing subframe connectors around upgraded exhaust, forget piecemeal and do them all at the same time.

A 350 is going to feel pretty weak with the LG4 exhaust.

A.I.R. is an emissions-reducing system. If you eliminate it, you're breaking federal law, but you can at least save money with headers that don't have provision for it.

There's a very informative sticky on the Exhaust forum about header choices/comparisons, including A.I.R. info.

 

ah ok..

and do i need a new chip?

edit: i don't see the part about AIR anywhere?

 

https://www.thirdgen.org/techbb2/sho...hreadid=204967

It's getting long-winded, but headers with & without A.I.R. are discussed.

You don't "need" a chip, but some like the L69 have more timing advance than others. I haven't tried mine with the original chip (I put a JC Whitney chip in soon after I got the stock LG4 engine in, and left it in when I did the mods). I didn't know until after I changed the chip that I had a fuel pump problem, so I don't really know what difference the aftermarket chip made.

If you don't have a knock sensor ('82-'84 LG4 did not), then you might not want the additional advance of a "performance" chip.

(Edit: Guess I haven't attached my sig yet so you know what mods I've made... Here 'tis.)

 

..