Never rebuilt a engine so I need advice.

[JeffP1167]

This will be a 1990 L-98 that needs it. It does run but prior to me buying it the motor blew head gaskets and water went in the oil. I have heard this can wip out bearings.

I am not against a stroker build but must be in reason because I live in california.

The car the motor is going into will be my 82 corvette so TPI and full emissions must be retained.

Car will never see a drag strip and it's only intentions will be a cruiser type car to grocery getting.

My suffix code on the block come back as a 70's block however it is a roller cam engine with 1 PRMS but the stamping on back of block comes back as a GM number 87-92 350 2 bolt block.

It does have the 113 aluminum heads.

I want to keep my stock TPI system, so a mild build would probably be best.

Obviously I cant run long tubes etc. etc.

So lets hear your ideas on a mild build that will net me more torque, not overly worried if it can't make 1,000hp but would like a higher torque out put since I plan on staying with 3.08 gears and a 700r4.

 

[kutmup]

I left California 10 years ago but from what I remember strokers where a good way to get added power without having smog trouble. IIRC hand in hand with the added displacement came the ability to add a bit more cam as the bigger engine’s faster port velocities (for the same cross section intake port) allowed a slightly larger cam to still pass a sniff test.

It was never clear to me about adding later engine stuff. The consensus was that a later engine could be used in an earlier vehicle but I could not get a clear answer about whether or not all related emission control had to accompany a newer engine. Using the TPI rather than the ’82 Crossfire injection might result in some scrutiny.

I believe some guys have gotten close to 300 RWHP form TPI engines that still passed sniff tests. Those engines had more torque than most gen I SBCs with similar HP numbers.

 

[JeffP1167]

Here is a clip of it running, never seems to make any weird noises and never puffs any smoke. Would you just drop it in and see how it does or go through it?

Maybe just rod and main bearings? Compression is great on it no cylinders below 175psi

It almost looks like it was a over the counter motor at some point, not much grease in usual places and in the flywheel area looks like new with fresh black paint.

I am not sure of what cam is in it but probably not a L-98 cam anymore, however it always ran nice and smooth.

 

[MYBAD79]

if it's not broken don't fix it..... you say it's not making noise , good compression and doesn't burn oil.... leave it alone unless you want more power......

 

[kutmup]

How is the oil pressure? As to put it in or open it up, how does pulling an engine twice bother you? In my El Camino swaps are no big deal so I've taken chances with engines for it. In my Vettes I don't want to do an extra swap if I can avoid it.

 

[JeffP1167]

it is out of the car.

 

[mrvette]

WHAT EVER you do for a cam, do NOT buy anything from TPIS, Chaska Minn.....the junk I bought was a ZZ9 roller can, and it FAILED....causing the nastiest kind of rough idle and even then, intermittent in the roughness, some days just fine, other days just unlivable......changed cams, and everything is fine.....

just so you know man......


I would let a machine shop do the short block, and heads, and do the final head assy yourself.....I have never successfully done any short block assy work, changed bearings, but that ring business and shit is too much....

:surrender:

 

[TimAT]

It's out of the car, put it on a stand, roll it upside down pull the pan and roll a set of bearings and a new oil pump into it. Compression and no smoke, rings are fine. Bearings and oil pump are cheap insurance against having to pull it and fix whatever got eaten when the bearings let go.

 

[SuperBuickGuy]

my brother built a motor for the 86 Corvette my dad now has... he built it to ZZ4 specs with some minor work to the TPI (better throttle body, higher pressure regulator). That car runs really strong, is stone-cold reliable, and still gets mid-20s for fuel economy. Best of all, it all plays nice with the reprogrammed computer - it started on the stock tune.

 

[JeffP1167]

It's out of the car, put it on a stand, roll it upside down pull the pan and roll a set of bearings and a new oil pump into it. Compression and no smoke, rings are fine. Bearings and oil pump are cheap insurance against having to pull it and fix whatever got eaten when the bearings let go.

The heads were resurfaced some time back and at that time they looked like they were re-done not long prior to the head gasket blowing. I had new valve seals installed as well.

When I bought the 90 it had milky oil and that is why I am concerned and was wondering about at least new bearings since I don't know how long it was run with blown head gaskets.

I know it always pulls around 19 inches of vacuum, oil pressure usually hangs around 40psi at idle and jumps when given gas, radiator pressure test holds 15psi for well over 30 minutes.

I am going to design my frame so in the event motor ever does need to come out, I remove it complete with the cradle and all.

I am not into computer tuning so prefer to use stuff that will work well with my stock prom, my first smoging will have to be checked by a referee so every possible thing must pass. I do have a new magnaflow exhaust system from this 90 which I plan on having altered to fit my 82.

 

[Twin_Turbo]

WHAT EVER you do for a cam, do NOT buy anything from TPIS, Chaska Minn.....the junk I bought was a ZZ9 roller can, and it FAILED....causing the nastiest kind of rough idle and even then, intermittent in the roughness, some days just fine, other days just unlivable......changed cams, and everything is fine.....

just so you know man......


I would let a machine shop do the short block, and heads, and do the final head assy yourself.....I have never successfully done any short block assy work, changed bearings, but that ring business and shit is too much....

:surrender:

Disagree!! I have a TPIS cam in 3 engines, never a problem.


Jeff, with your components there's not a whole lot you can do unless you are willing to break out the die grinder and hog out the manifold and heads,. The cam is pretty lame in stock form, actually TPIS has a superL98 cam or whatever they call it and I'm pretty sure it's CARB legal. You will pick up a good amount of mid range hp and tq with that cam, even with it's relayibly low lift. Add some 1.6 rockers to topm it off. I'm pretty sure the late TPI engines got a much lamer cam than the earlier ones even though they used flat tops instead of dished pistons (higher CR)....

With a nice little cam and some 22lbs bosch III injectors it should purr along nicely. The stock multecs are absolutely terrible!

I would do as Tim says, leave the short block and get some bearings and a pump. Do note the bearings though, if you find those 0.005 bearings that GM used frequently on these things you need to get 2 sets of bearings, a std and a .0010 sized set and use half of each set. GM used .0005 incremented sizes in assembly and none of the aftermarket sells those

 

[JeffP1167]

WHAT EVER you do for a cam, do NOT buy anything from TPIS, Chaska Minn.....the junk I bought was a ZZ9 roller can, and it FAILED....causing the nastiest kind of rough idle and even then, intermittent in the roughness, some days just fine, other days just unlivable......changed cams, and everything is fine.....

just so you know man......


I would let a machine shop do the short block, and heads, and do the final head assy yourself.....I have never successfully done any short block assy work, changed bearings, but that ring business and shit is too much....

:surrender:

Disagree!! I have a TPIS cam in 3 engines, never a problem.


Jeff, with your components there's not a whole lot you can do unless you are willing to break out the die grinder and hog out the manifold and heads,. The cam is pretty lame in stock form, actually TPIS has a superL98 cam or whatever they call it and I'm pretty sure it's CARB legal. You will pick up a good amount of mid range hp and tq with that cam, even with it's relayibly low lift. Add some 1.6 rockers to topm it off. I'm pretty sure the late TPI engines got a much lamer cam than the earlier ones even though they used flat tops instead of dished pistons (higher CR)....

With a nice little cam and some 22lbs bosch III injectors it should purr along nicely. The stock multecs are absolutely terrible!

I would do as Tim says, leave the short block and get some bearings and a pump. Do note the bearings though, if you find those 0.005 bearings that GM used frequently on these things you need to get 2 sets of bearings, a std and a .0010 sized set and use half of each set. GM used .0005 incremented sizes in assembly and none of the aftermarket sells those

It doesn't have the multecs anymore, I had a brand new set of bosch 19lb injectors I put in it just to see if the car would run. It seems to run pretty good with them when fuel pressure is set at around 50psi. I have heard vette L-98's used 24lb injectors but F-body L-98's used 22lb, do you know if this is fact?

I heard the vettes used 24's because of higher compression then the F-body, I think F-body has 9.5:1 and vette has 10.25:1

 

[Twin_Turbo]

19s are for a 305 you need 22s, the LT1 came with 24s. It's my understanding that the F and Y body L98 used the exact same injectors. Late F bodies have flat top pistons also. Same as the vettes.

 

[JeffP1167]

19s are for a 305 you need 22s, the LT1 came with 24s. It's my understanding that the F and Y body L98 used the exact same injectors. Late F bodies have flat top pistons also. Same as the vettes.

But L98 f-bodies had 083 64cc heads but the vette had 113 58cc heads. I will look into that L98 super cam you were talking about. I am not sure what pistons this engine has (it could also be a 305 as far as I know since it isn't matching code wise to what it should have had) But when I did the head gaskets 350 gaskets matched it's cylinders correctly.

I will pull the pan and timing cover and at least do rod and main bearings as suggested.

Can the cam be changed without removing the intake? Or do the lifters become a problem?

 

[JeffP1167]

Okay, the block has GM 5.7 LG SGI stamped kinda where the bellhousing bolts up to the drivers side of the distributor. On the sides of the block it is stamped 638

 

[Twin_Turbo]

What's the suffix on the stamp pad? Should say 5.7 on the dr side rear of block

edit nevermind, just saw post above

 

[Twin_Turbo]

19s are for a 305 you need 22s, the LT1 came with 24s. It's my understanding that the F and Y body L98 used the exact same injectors. Late F bodies have flat top pistons also. Same as the vettes.

But L98 f-bodies had 083 64cc heads but the vette had 113 58cc heads. I will look into that L98 super cam you were talking about. I am not sure what pistons this engine has (it could also be a 305 as far as I know since it isn't matching code wise to what it should have had) But when I did the head gaskets 350 gaskets matched it's cylinders correctly.

I will pull the pan and timing cover and at least do rod and main bearings as suggested.

Can the cam be changed without removing the intake? Or do the lifters become a problem?

Yes vettes had higher comp. and a little more power but not that much.

Intake needs to be removed, a spider plate is spring loading the roller rocker dog bones, they must be removed to pull the cam out.

 

[JeffP1167]

did some wire brushing on it and it is actually looking nice. Excellent upgrade over the CFI motor it will be replacing, wish I could have a LSx but that isn't in my budget

 

[mrvette]

WHAT EVER you do for a cam, do NOT buy anything from TPIS, Chaska Minn.....the junk I bought was a ZZ9 roller can, and it FAILED....causing the nastiest kind of rough idle and even then, intermittent in the roughness, some days just fine, other days just unlivable......changed cams, and everything is fine.....

just so you know man......


I would let a machine shop do the short block, and heads, and do the final head assy yourself.....I have never successfully done any short block assy work, changed bearings, but that ring business and shit is too much....

:surrender:

Disagree!! I have a TPIS cam in 3 engines, never a problem.


Jeff, with your components there's not a whole lot you can do unless you are willing to break out the die grinder and hog out the manifold and heads,. The cam is pretty lame in stock form, actually TPIS has a superL98 cam or whatever they call it and I'm pretty sure it's CARB legal. You will pick up a good amount of mid range hp and tq with that cam, even with it's relayibly low lift. Add some 1.6 rockers to topm it off. I'm pretty sure the late TPI engines got a much lamer cam than the earlier ones even though they used flat tops instead of dished pistons (higher CR)....

With a nice little cam and some 22lbs bosch III injectors it should purr along nicely. The stock multecs are absolutely terrible!

I would do as Tim says, leave the short block and get some bearings and a pump. Do note the bearings though, if you find those 0.005 bearings that GM used frequently on these things you need to get 2 sets of bearings, a std and a .0010 sized set and use half of each set. GM used .0005 incremented sizes in assembly and none of the aftermarket sells those

It doesn't have the multecs anymore, I had a brand new set of bosch 19lb injectors I put in it just to see if the car would run. It seems to run pretty good with them when fuel pressure is set at around 50psi. I have heard vette L-98's used 24lb injectors but F-body L-98's used 22lb, do you know if this is fact?

I heard the vettes used 24's because of higher compression then the F-body, I think F-body has 9.5:1 and vette has 10.25:1

Marck, I dunno man, how much use do those cars have on those cams?? mine lasted a while, maybe 15k miles as a guess, and I would guess you seen the pix I posted , and the stock L98 cam you sent was just fine and has lasted longer than that ZZ9 POS did. been nearly 2 years now.....

and the thing that drove ME crazy was the intermittent bad idle with it, and the thing is fine since changing the cam,

:cussing::skeptic:

course I put the damn thing in there in late '97 and it lasted maybe a year or so before the really ragged rough idle set in....when it was NEW it ran great....but piss poor durability.....I"d keep a close eye on them if I was you....when the shitty idle starts, that's where I would go first.....


:skeptic:

 

[Twin_Turbo]

One of them has over 30.000 with the TPIS cam. It's my 3/4 year daiy driver (not with snow and salt)

Your cam issues could have been caused by a plethora of things, like a manuf problem with the harneding or misadjusted rockers where the lifters hammer the lobes, inadequate lubrication for some reason... some lobes had issues, others not. The main difference I see is that all my TPIS cams are billet steel cores with pressed on cst iron gears. Yours looks like a austempered core but I don't think they used that.