hey, I have been dilligently reading the forum for a couple days. I have a question, that I realize is not the regular thing on here, but I was hoping someone would toss their opinion (with explanation) my way. I have a 89 350 TBI from a G20 van that I will be swapping into my 95 Jeep Wrangler (YJ) this spring. I will be running a one ton truck (NV4500) 5 speed behind it. I primarily rockcrawl, so slow going is the name of the game. Obviously my need is torque just off idle. This engine will rarely go above 5,000 rpm (it will be used for some mud, and street too). But instead of making our vehicles lighter, generally with all the stuff we add, it gets much heavier. So, I will be tearing it apart in the coming days to see what it needs , if anything, for internals. I will basically be doing a bearing and ring job in the least. The question is....I'm considering (my wallet is considering it too) doing the 383 stroker while I'm in there (looking at the Speedomotive 1 piece seal kit). I've noticed references to 300hp as max available from the stock TBI set-up. So, do you think the 383 would be worth it for now (since a new intake and TB would just push it definitely above affordable for me now)? And, in general, what else would you recommend for my torque curve needs? Thanks, I'd really appreciate any thoughts, Charly

I got an '89 YJ. What are you swaping out to put in the 350? What t-case are you putting behind the nv4500?

LOL...ok.

I am taking out the 2.5 L (already swapped it for an 8274 actually, I got the winch, he'll get the engine this spring .

Behind the NV4500 (it's an early GM with the 6.34:1 first too...woohoo) I am going to run an Early Bronco (swoon! gasp!) D20. This will power the 4.88s in the Detroit'd, disc'd 14 Bolt and the 44 front. And all this will turn at least 38" TSLs (haven't dropped the change on the tires yet).

I'm probably going with a Centech harness, still deciding.

No TBI in your 89?

Charly

Oh, and does anyone know what volume my combustion chambers would be? I can't seem to find that anywhere.

thanks,

Charly

damn sounds dope. check this out http://forums.jeepsunlimited.com/ubb...ML/003754.html I just got a spare TBI to put on my 4.2L. I need to start gathering other parts. You're heads are 64cc's I think. check www.sdpc2000.com maybe they have the L05's heads listed somewhere. You gonna shave the bottom of the 14 bolt? what springs?

Well I can tell you that if you have the stock heads, they are more than likely the 14102191's, or 14102193's.

Those are 76cc chamber (aka open chamber) swirl port heads. Not bad for low end grunt. They'll flow OK ~ 5000RPM, but don't expect your comp ratio to be very high.

Usually with flat top slugs, and a .040" gasket, you're gonna be around 8.6-8.7:1. You can get it a hair over 9:1 if you use Mr. Gasket's of FelPro's steel shim gaskets. They compress to around .015-.020" depending on what brand you get.

Just keep the cam modest.

AJ

TBIs are great for rockcrawlers. Very good choice!

Check out <a href="http://www.racer-x.f2s.com/proc/stroker.htm">this</a> like to help you decide on the 383 or not. I found it very informative. Personally, I think a 383 would be great for a rockcrawler, but you're gonna have to do something about the intake flow.

It all depends on how much and where the power is going to be. If I were to build a 383 TBI and use the stock tb unit I wouldn't want to make more than 300hp and try and make the peak power below 5000rpm. The longer stroke (and displacement) is going to want to suck in a lot more air from the intake than a normal 305 or stock 350, for this reason you want at least the performer intake manifold. I would use the RPM version just because it's that much better for larger displacement engines. Don't go with a single plane if you're into rock crawling, no reason too, especially since you want the most torque down low. Fastbroker has a jeep, ask him what cam would be best. I would opt for the larger TB unit with the 383 cubes, no reason to hold back that combo with the small intake. The cam and intake manifold has to be matched. If the block is roller, keep it roller.
Awesome deals on take-off parts.

Wow, thanks for all the help.

tas,

I'm running a combo of OME and Waggy springs SOA with TJ flares and a 1" BL. The 14 bolt will be shaved (but not cut aand plated...just yet) when I install it this summer (I currently have an 8.8 in there). I'm finishing up rebuilding the 4500, and am ready to tear into the engine. That JU thread looks good.

Just some more info:

I want to (well, more like I should) keep the EGR system.

If I go Performer, should I get the 350-3701 and get an adapter to mount the TB unit? Or is there another option?
I see Jeg's lists a TBI Performer cam, but not a manifold.

Fastbroker, what do you think? (would it be appropriate to email him, if he doesn't see this thread?)

What is the larger TBI unit? Is this the Holley unit I've seen some info on?
I think for money's sake I'll have to pass on the larger TB unit for now, but that requires larger bores, correct?. Are the adapters available with the different bores?

So how does 383 (thanks for the article Jza) with some kind of Performer intake (carb spreadbore w/ adapter or a TBI unit) and the stock TB unit (for now) and a cam (lol..."a cam", boy do I sound like an a$$..lol) sound? And would a spacer be worth it?

...and guys (gals, whatever) I realize all these questions may be annoying, but seriously, I really appreciate it, thanks. I really don't like to use smilies much...but if you guys had one I'd give ya one of these :beermug: .....be gentle....mommy?........

I figure with all of this I will definitely need to have a chip burned to make use of the mods. I have a 1227747 with a stock manual tranny chip I was gonna try and run. I guess I have to start learning about burning chips huh.

Is there anywhere I can confirm the volume of the heads (thanks AJ_92RS)? I found nothing at Scoggins-Dickey.

And the other thing I can't find is an answer to this: I know that with the two piece seal blocks you need to get he 400's externally balanced flywheel and damper. Do I, with the one piece seal? The reason I ask is I was nosing around the GM Performance parts site the other night and saw that they say the flwheel is already externally balanced (unless I'm misunderstanding it). That Speedomotive kit comes with a new one piece seal crank, so is there even a 400 flywheel that will fit a one piece crank?

Thanks,

Charly

I think the TBI truck heads ar 64cc in the 350. that is why they were around 9:1 compression instead of the '86 and olders with the 76cc and 8:1 ranged compression. Also, A TBI 350 with the stock nasty cam and intake is perfect for what you are going to be doing. It made peak power at 4000 and peak torque somewhere around 2500. Almost runs like a diesel. With the 4.88's and small tube headers, it would be able to rip a house down. If you go 383, you will need more fuel pressure, and maybe the Edelbrock perfomer TBI intake, nothing more though if you want max lowend torque. My roomate has a '97 wrangler locked front and rear with 4.88's and 37" tires. He has ever possible mod I can think of, minus a V8. The best one he has for rock crawling is a hand throttle

Yeah, the heads I have are marked 14102193.

So these are 76 cc? Anywhere to confirm this?

TBIWORKS,

The power figures I have are (like you said) 210 HP @ 4k and 300 Ft.lbs @ 2,8K for the stock L05. That's 9.3:1 compression.

For a fuel pump I will retain the in tank pump for the MPI that was on my 4 cylinder.

I have a hand throttle too, it is very useful for times when you nedd three feet.

Thanks,

Charly

Yes, those are Lo5 heads with 76cc. Same as off my Caprice.

I looked everywhere to confirm the cc's on those heads but couldn't. I could have sworn L05s were 64cc.

Hey guys...

Someone above was right about any OEM cam being perfect for a rockcrawler/daily driver. Perfect. No need for the 383, either, in your case. If you want a roller cam recc., get the smallest 112 lobe sep cam Comp has in their XE line. But if the mileage/shape of the motor you have is ok, don't bother.

Only thing I might be concerned about is that "g-spot" motor you have. I am no master of models/specs but some of those van motors are "detuned" 350s with lower compression and benign spark tables for reliability in fleet vehicles. The PROM/spark stuff can be fixed, but the compression/parts are gonna cost you if they need changing.

IMO, do a leakdown test and compression test on the motor. If they are ok, change the valve seals, regasket as much as you feel like and put the engine in and go rockcrawling. ANY 350 with 4.88's in LOW RANGE is more than enough. Much more.

How many miles on your 4.11 axles. Wanna sell them outright???? or maybe bartar for some 325/60/15 (31x12.50x15) BFG All Terrains???


EDIT: Good choice on the NV4500. overkill is good.

LT1 B-body car cam is torky. look for them on Impalla SS boards.

Thanks for responding, I was beginning to think it was something I said....... hahaha

Yeah, I've looked at all the lists and tables (although most are copies of one or two) and not one listed the cc volume. Most just said "350"...lol.

The van I got it from was a window van that served as transportation for a band, and before that was just a private individual's. The auto tranny was toast (that's why it was in a salvage yard), but the rest of the vehicle was in great shape actually.

I feel no pressing need to get a roller cam for now, and if the stock cam is decent (I imagine it would be built for low end and economy) I'll just keep it. Anyone know the profile? (or is all info for this engine a big secret...lol).

The engine is mostly apart (heads and pan are off, pistons and crank arecoming out soon) so a leakdown/compression test aren't possible right now. I'll mike the cylinders and crank, might just rering/bearing/gasket it.

Anyone think the pressure from the stock intank fuel pump (for the MPI) will be too much for the TB unit? As of right now I do not know it's pressure output, but I will search for it.

As far as my 4.10 axles are concerned, they are long gon, I've been running the 4.88s for a year now.

Personally I'd prefer a crawl ratio of 125:1 or so, but with the planned set-up (stock 2.46s in the tcase) i will be at 76:1.

thanks again,

Charly

used roller cams can be had for $25. That's why we like them

If you can get in the Carter fuel pumps book at your local auto parts house, it has the pressure and flow specs in the back listed by part number. Just look up the carter part number for the stock jeep pump and compare it to a the van's stock spec carter pump. This is how I learned that the L03 camaro pump is the same part number as a 454 SS, and it flows 38gph at WOT. I bet the G20's pump is the same as all TBI pumps are. This is more than a 305TPI's pump! It's just the pressure at the regulator that makes the difference I guess. the stock peanut cam is something around 180's:190's@0.50" and high three's on the lift. Be careful in the pump deal, some of those little 4's and 6cyl's had super high fuel pressure rates and pumps.

Yea i think the stock tbi cams are around 194 on the intake and aobut 202 on the exhaust side. As far as lift goes i am not sure but for some reason I am thinking around .410 or something not sure though.

Josh Salley


1994 K1500 Suburban TBI 383 335 hp 470 ft lbs, 4.10's, 33's Straight out duals, three chamber flowmasters, catco cats, full length ceramic coated headers, msd ignition. Only 18 and still in school.

Go to www.mortec.com to see a few specs on yer heads (listed by casting...)

I tried that. They didn't have the cc's listed

oh...

Yeah, several of the charts I found when searching were actually just copies of the Mortec chart.

Sheesh, being a Chevy and all, I thought I could easily find the underwear size of the guy who cast the block...LOL

Have you called dealership? Maybe parts department could help you or something...

My 1993 Suburban 194 heads are 64cc. I think the 202's are 76cc. The burban is rated at 210hp. Call Brooks Chevrolet in Bellevue, WA. Ask for Scott in the parts dept. HAve him run the cast #'s.

Did they ever make 2.02's in a TBI 350? I have a set of TBI truck heads off of a 3/4 ton with 4 bolt main caps. I wonder if they are 2.02's?

Yes you coulf get either 194's or 202's on 8600 and bigger given weight vehicles the had sodium valves and water jackets around the exhaust valve stems.

Alright, this is what I've found.

These are all Airtex brand PNs and specs (available at Carquest):

-------------------------- GPH at WO --- Pressure shutoff

E8229 95 YJ 4cyl MPI --------- 45 --- 80-100 psi

E7001 88 YJ 4 cyl TBI ---------- 40 ---- 30-46

E3902 89 Chevy G20 Van 350 TBI --35 ----- 12-17


So, what's surprising to me is that the 350 (same for the 454) provides less flow than either 4 cylinder pump. I expected it to be the contrary.

And the best thing is that dimensionally all three pumps look like they'd be interchangeable (all are same diameter...4 cyl TBI pump is a bout 1" longer than the other two). the intake filter socks have slightly different mount diameters, but it looks like if you keep the sock with the correct pump, it will work fine. Wiring is two wires.

This is great news, because by all appearances, I can keep my tank and just change the in tank pump.

A TBI system only needs 8-13 psi to operate, MPFI or MPI needs anywhere from 40 to 60 psi.

Yep. I know, my GM tech manual lists 9-13 for the GM TBI, and my jeep manual says 39 for my MPI. I just needed to know more detailerd specs, and actual dimensions to compare pumps, and the internal pressure regulator maintains the pressure at 9-13, but I was interested in what the inlet pressure rating was.