Hello,

Alright, I had an Idea, let me know what you guys think.

I have a new rebuilt TPI setup that I bought a while ago. I was planning on either putting it onto my current motor or build a new motor for it. There are 2 problems with that:

1: My current motor is the original L-82 with probably 100,000 miles on it. While it runs great and is extremely reliable, I'd prefer not to run it too much and possibly damage it. I dont drive like a maniac, but I have been been very subdued in my driving style for fear of damaging the engine. It also needs new valve stem seals as it burns about a quart of oil per week because the seals are done so it burns it at startup.

2: The other option I had was to build a new aluminum head fully forged roller cam 383 for the TPI. The only problem with this is the money, it would be very expensive to build this engine, and it is money that I dont have to put purely into an engine (I'd rather put in a 5 speed with that money)

So I got thinking, Could I purchase a used, low mileage (sub 50k) TPI motor and drop it in? They go for very low price, and already have a roller cam and aluminum heads.

Now I know of a few possible problems, do you guys know if these problems could be overcome?

My TPI was built for the angle bolt pre 86 intake bolt pattern, so the heads would either need to be replace or ......could they be modified to have the more angled bolt style? Also do the L-98 heads have the ports and spark plugs compatible (aka stock locations and angle) with my current headers , which are the hedman elite sidepipes headers?

I know it is a 1 piece RMS, is there any way to convert or change something to work with my current 2 Piece RMS flywheel (I have a 4 speed)? Also, is there a hole for the clutch ball stud in the block? Are these blocks able to use my old style motor mounts?

I'm probably overlooking something, but what do you guys think of this? If you guys have any other ideas, let me know.

Thanks,
Will

 

If you get a TPI motor, you want one of the aluminum head variants (87-91, maybe 92 in F-bodies, only really familiar with vettes.)

The L98 heads have the same intake manifold bolt pattern as the L48/L82, not the Vortec pattern.

They do, however, have center bolt valve covers so your valve cover will have to change.

You'll need to get a different flywheel.

Not sure about the boss for the clutch linkage.

Motor mounts will bolt up fine.

You can actually bolt a TPI setup directly to your L82 heads. Don't forget you'll need to modify the fuel system to support EFI.

 

Thanks for all of the info above. That really cleared it up. One thing also is that on my current engine, I would need to do the valve stem seals sooner then later, and especially before I installed the TPI onto it, as the high zinc oil being burnt would not be too good for the 02 sensor! By the way, what style stem seals did my L-82 come with from the factory?


Thanks,
Will

 

Also would the stock L-98 engine oil pan be workable without any mods with my car?

Here is one more questions- With the TPI, is there anyway I can use my points distrbutor? With the roller cam would I need a brass or other material gear? For the Tach signal, do I need a signal adapter so the ECU can read it? I'd like to keep my point distributor if possible, but if needed I can get one of those tach drive HEI units they sell.

Also, are the TPI l-98 engine externally balanced? Would all of my current pulleys and accessories bolt right up to this engine? If I were to get an engine from a MT car could I use that flywheel with my current clutch?

Will

 

Ok, so what I'm thinking is I'll change my valve stem seals on my current engine sometime soon (to stop the rabid oil burning!), and later during spring I'll try to find a suitable engine to drop in.

Does anyone know about the questions I had above?

Thanks,
Will

 

With TPI, you really should run the HEI system that goes with it. Pretty sure if you run a stock ECM it will go into limp mode without it.

I don't think they're externally balanced, but I could be wrong.

All of your accessories will bolt up to the block and heads, but if you have something in the high-center area(on my 78, there's an AIR pump there), it will most likely interfere with the throttle body setup.

It would also be a good idea to switch to an electric fan setup, as the TPI system can control that.

There are a lot of people in the C4 Technical forum who are much more experienced than me at this stuff. AGENT85 is one that comes to mind.

 

The C4 guys have always been very helpful whenever I had an EFI question.....Will, also keep an eye on the C4 parts section in case an engine you can use comes up for sale

 

I would get a megasquirt (or other AM ECU) and run that. Will allow more install options (spark, trans, etc...).
A microsquirt could also work depending on your install plans for the TPI. If not then the full Megasquirt2 will work.

 

OE '86 up / 1 pc rms sbc motors are routinely referred to as internal or neutral balance ... But ...

But ... that's not so accurate ... because ...

Because ... while their harmonic damper at front is neutral ... their flexplate or flywheel at rear does have a spot-welded or cast-in CounterWeight ... I think of those motors as "hybrid balance"


add edit
there's a company tpis.com that's been doing tpi swaps & upgrades for years ... they did sell lotsa new & used parts for retrofit ... maybe they still do ... while it's more probable most of their current business is based on LSx. Years ago they swapped in a new ZZ4 fitted with TPI ... and I got the new takeout GMPP coil-in-cap HEI that shipped with the ZZ4 ...cannot be used w/ TPI. Suggest check w/ TPiS.

 

TPIS sold me a bum ZZ9 cam years ago, and it's ran like crap for years, upon pulling it out for install of a L98 cam, I find the cam had lost a huge amount of the hard surface, one guy there suggested I send it back, the other guy there flat refused to do anything, so for the insult I wasted 15 bux on top of the **** poor durability of their product.....I would not go TPIS for a damn thing....

TPI uses a computer HEI, mechanically same as any HEI, so it will work fine....don't understand the comment....

I got tired of the L98/TPI setup and switched to a LT1 induction off like a '94 vette....had to remachine and TIG weld the thing up to fit, cut out the EGR fittings, plug the passages with plaster of Paris, used a dizzy mount from another carb intake mani, welded it up and it's all fine....mounted hose fittings to the intake up front and rear water passages....

 

dang you seem to get more than your share of bad luck.

TPiS sent me a never-run large-diameter coil-in-cap genuine GMPP HEI for $40 ... sweet!

afaik, most TPI w/ GM ECM use a small diameter HEI w/ External coil. I guess TPiS knows lots more about TPI than I do. They couldn't use the large HEI that came w/ ZZ4 with their TPI ... so I got (takeout) dist. The TPI-ZZ4 swap-retrofit was someone else's project; not mine. I've never had any GM TPI / TPiS. I simply got a great dist for cheap.

 

Thanks for the info. I'm not running a GM TPI wiring harness or ECU, I'm going to run the FAST ez efi system. Idk if that can run the electric fans (But I might just do them anyway!) and no AIR pump for me. I had read somewhere that they were externally balanced but I guess they were wrong.

Thanks,
Will

 

Yeah I'll definitely go to them, thats a good idea, and I'll see if there are any engines up for sale.

Thanks,
Will

 

I plan on using the FAST EZ EFI system. I want it as simple as possible. I'll look into the megasquirt though.

Thanks,
Will

 

Ahh alright thats what I had read about the TPI motor balance! I knew it had something to do with the flywheel. Ok So I could use the balancer that is on the engine and a new flywheel to use with my 4 speed?

And I'll look into those guys and see what info they have.

Thanks,
Will

 

Wow that is a lot of trouble you went through, Gene!

I looked at their (TPIS) stuff on ebay and they have some TPI stuff, but I already have a complete, rebuilt TPI so I should be good with that. I will need to buy the fuel system stuff, the wiring harness and figure out my engine plans.

And for the FAST EZ EFI, all it needs is a tach signal so I may just throw in one of those Tach drive HEI units they sell.

Thanks,
Will

 

The FAST EZ EFI can switch the electric fans, as well as fuel pump and can accept signal from the A/C to kick the idle up when the compressor engages.

Yes, you'll need something to get you a tach signal. An MSD spark box will be able to output one as well.

Good luck, I've done a lot of research on EZ EFI but have been waiting due to the fact that making your car run better than factory is illegal in CA.

 

TPI isnt worth the time to swap. there are many better aftermarket efi set ups out, the oil pan on an l98 is a standard sbc oil pan

 

I have always liked the style of the TPI and the massive torque producing capability. Also, I am using the FAST EZ EFI ECU and wiring, so that kinda covers the "better aftermarket" solutions lol. Also, I'm 17 (almost 18) and this would be a good project to break myself in on the EFI thing, even though I already have much experience with EFI and computers (I run a computer business). Maybe in the future when I'm older I'll drop an LS3 into my Corvette....who knows!
Hahaha those foolish smog ***** - They still havent given CARB clearance to the EZ EFI?

Will

 

Spark box with either. And no CARB clearance AFAIK.