With all the LT1 B bodys croping up in the yards for super cheap I'm seriously considering an LT1 swap over my previous plan of cobbling together a TPI topped vortec with LT1 internals or an aftermarket rotating assembly.

I figure the LT1 even the iron headed ones will give me everything I'l want from the other motor plus the benifit of running either the TPI intake or the LT1 intake.

Heres my plan (based on several assumptions that I hope you'll be kind enough to clear up for me) for a simpler LT1 swap.


I know the LT will bolt to my 700 and my 1st gen style mounts, I am assuming from what I have seen online and what I have seen on actual motors in the yards that the LT1 and 1st gen heads share the same or nearly the same accesory bracket bolt pattern.

If my TPI brackets fit the LT1 then I dont have to wory about making new AC lines, buying the new accesories and brackets with the motor, splicing the harness etc.

What I'm not sure about is if the LT1 water pump and it's inlets and outlets will clear the TPI brackets, specificaly the alt bracket.

My late TPI intake should bolt to the LT1 with no issues. I know the LT intakes are sometimes modded to fit the 1G heads. And the TPI distributor should fit the LT with the LT's oil pump drive removed.

I'm sure there is a way around the missing water pump pully, someone at some point must have swapped an electric pump into a TPI car and kept the TPI acc drive. And the LT pully and flange can be replaced with a 1G crank pully.

Getting the LT manifold machined for a distributor is nothing new and I wouldnt have to wory about the coolant crossovers like people do when placing an LT intake on a 1st gen block.


So if I'm right I should be able to simply replace the TPI block and heads with the LT block and heads with nothing but a water pump delete kit.

I would get a lower mile engine with higher CR, better chambers, better ports and reverse cooling. All without touching the harness, the AC lines, the coolant system or the ECU programming.

 

1. The heads do not have the proper holes drilled for the TPI accessories plus without the waterpump pulley, you couldn't run the TPI accessores anyway.

2. The heads to not have water passages in them for coolant to flow into the intake.

3. The waterpump is a special unit for the LT1 and is different than a standard SBC waterpump, plus it is driven off of the camshaft instead of a belt.

4. The TPI intake will not bolt up directly to the LT1 heads, the heads have more of a vortec style intake port instead of a standard SBC port.

5. You would be totally choking the engine with the TPI intake, this is why people are taking the LT1 intakes and putting them on TPI cars due to them flowing better.

6. The 700R4 will bolt to the LT1, you will need to run a '93 throttle body to get the provision for the TV cable, but people have found out it's easier to run the 4L60E with it.

 

The 700 with need either vacuum control or 93 harness/ECM. Without one of those, you get no lockup

Building a harness is for the new engine, not just its accessories. If you are looking for a TPI controlled LT1, there is one on the forum. He likes it, but it doesnt change the fact that newer PCMs are more powerful, more effcient and easier to tune

Notching the K-member and building some fluid lines are minute details compared to the actual swap

 

#1: I was afraid that was the case, but like I said I'm sure someone at some point has run an electric pump on a TPI car and either cobbled together a delete or found an existiting option that would work.

#2: That wouldnt be ab issue, the LT1 cooling system is entirely independant of the manifold. The passages would be there in the manifold but they would be dry, there would be no effect on the operation of the engine.

#3: Yes the water pump would be bolted to the LT block just like original, it's the missing pully that would cause me the problem. The pump and cooling system would be 100% LTx.

#4: The manifold will bolt up to the LT heads as the bolt patern is the same. I wasnt sure about the port profile though.

#5: I would be, I see it as something closer to a standard 10.0:1 cr 350 with vortec heads. I want to do the LT1 manifold anyway but I was thinking the TPI intake would atleast make the initial swap a near bolt in affair. The LT1 manifold could go on later.

#6: This is where you got confused, since I would be using all the original TPI electronics it would be simple to use the TPI throttlebody on the LT1 manifold and simply keep the original TV cable. People who have swapped LT manifolds do exactly that.

Pocket, I'll be using the TPI ecu and wiring, I'll have lockup.

I realise the newer ecu's are all around better, thats why I'm also planning the 411 swap. I'll need to ditch the opti to do that any way so I dont want to spend a lot of time swapping in one harness and ecu then do it all again.

The actual swap as I envisioned it would have been no more than simply swapping one 350 for another, in that case the harness and fabrication would have turned a simple afternoon swap into a drawn out and expensive conversion. Double or even tripple the work.

 

The simplest LT1 swap would be to swap in an LT1.

Somebody please explain to me why anyone would want to bastardize a perfectly good LT1.

Somebody!

 

 

it's almost like putting a carb on an LS series motor, a totaly waste of a good motor.

 

How is an LT1 with an LSX era ECU a bastard? Because it has 1G type accesories on it? Like I said the TPI intake would be entirely temporary.

Now if someone has anything to say that IS NOT based on some lame sense of automotive morality I would like to hear it.

 

Actually it wont. The ports are close enough but the bolt pattern is off. The 4 corners are pretty close but will have to be slotted as the SBC to LT1 angles are different. The middle 8 arent even close

Why not simply go with the LT1 everything? Intake, wiring and accessories. It would massively simplify the part hunting/modifying and let you focus on the swap at hand instead of how to make TPI stuff work with LTx

A franken motor like this is sort of like the SBC block that takes LSx heads. Its a good idea to use what you've already got with the benefits of both parts, but the down side is swapping the whole thing in usually costs less in the end

BTW, TPIs with electric pumps either use a pump with an idler pulley or swap to the older V-belt accessories. Unless you can figure a way to attach an idler to the LT1 WP, you may be stuck with V-belt TPI stuff

 

Well, you did say:

TPI ECU {sic} is hardly "LSX era".

Morality? Try common sense.

For instance:
Go through all the modifications for a temporary install? Not a case of "automotive morality", but totally missing what sense it makes. You'll do more work to graft the TPI stuff onto the LT1 than you would to graft the LT1 into the car. You'll have a better product, and a better final product, just swapping in the LT1.

 

Ok so you cant read Thats ok, I dont judge


And yess decrying hybridization ad bastardisation is moralising in my opinion, hotrodding is built on "bastardizing" cars to make them suit our tastes and it's something I have become pretty good at.

My Mazda uses parts from half a dozen different cars of several different makes and is imo a much better car for it.


But despite yhr lack of help i recieved this time around I have found out what I needed to know to decide it's not worth the hassle, I'll be bastardizing a vortec 350 instead

I was aware of the bolt pattern difference but it slipped my mind in the midst of the other details I was looking for, The the LT's acc bolt pattern looks to be nearly identical atleast on the drivers side but 2 of the 3 holes are wrong on the passenger side.

I found no info on running a water pump delete with the stock TPI style acc drive.

I figure a vortec 350 with LT internals will land me almost exactly where the "different way" LT swap would anyway, I'll just have to invest the work on assembling the motor rather than making the external bits fit the LT block. Only thing I'll be giving up is the reverse cooling.

Unless a slightly higher compression 350 with vortecs and TPI would be a bastard?

Again how would the LT swap I outlined (if it were viable) be a bastard when the vortec headed 350 that has been replicated thousands of times NOT be a bastard?

 

You would still have to find a TPI base for the vortec heads for it to fit properly. A Vortec is nothing but a standard 1 piece RMS SBC with roller provisions and a set of swril port heads on it, running a special distributor that can be run with a PCM that is like the LSx style (alot of them I've seen actually had the LTx style PCM, but newer ones could be different), people put vortec heads on a TPI car all the time and retain the TPI ECM, most of the vortecs out there were TBI so it would be like a TBI -> TPI swap.

There is nothing special about the LT internals except the PM rods (the crank and pistons are actually different as well LT1s are actually 10.4:1 and that is from the heads) 1.94 intake, 1.50 exhaust valves and 54cc chambers vs the 64cc on the vortec with the same size valves coming out to be about 10:1 CR with standard flattop pistons.

The part number on the Vortec TPI base (if it's still available from Scoggin Dicky) is 12498060

 

I wouldnt antagonize mods, especially mods that go out of their way to help people like five7kid and Stephen 87

Next, using a 0411 PCM is fine. Read my threads on harness building and the TPI OBDII thread about parts needed. The came up before you even mentioned the new PCM, when you were planning the TPI ECM

Aside from the nice PM rods and nodular crank, whats the benefit. It'll be a mildly high compression SBC with weak rod bolts and cast pistons. Nothing spectacular that cant be ordered from summit new for around the same prices as a pieced together used setup

I still dont get why you cant use LTx accessories and everything else. If the B-bodys are popping up so much (they are) why not get everything related to the LTx?

 

Actually, the LT1 had Hyper pistons instead of cast

 

PM rods were all they made starting in the early 90's as well.

 

ls six-

can you explain exactly what your trying to accomplish? to me, it sounds like you'd be best off just swapping an LT1 in and calling it a day.

 

Damn, my post wasnt accepted so I gota do it all over again

Sory about the attitude in the last post.

Updates, The LT1 and late 1st gen accessory mounting holes are the same. i had pics in the post that didnt go up but you'll have to take my word on this.

EDIT:




PACE Performance PAC-24502609



1g block with L98 heads, note the 3 bolt holes per head. Also note the 2 bolt holes near the crank center line, there are 2 more on the passenger side.



Lt1 long block, note the identical pattern in the heads, and it's hard to see in this pic but they have the 2 holes per side near the crank.

The plugs for the un used steam lines might need to be made flush with the heads but it's minor.


This means the stock TPI front drive will fit the LT1.

I have seen a pic of them mounted on a 1st gen block with LT heads and intake.

The TPI manifold will fit without a lot of work, I even have one with a fubar T stat housing that woulf be a perfet candidate. I would likely hust mod the LT manifold for the disty though.

I do want to keep the disty since the 411 ecu with the express code wont run the opti.

So we know the LT will bolt directly to the trans and mounts, we know the TPI TB will fit the LT manifold (I'll need to clearance the TPI pass side bracket for the IAC connector) and work with the existing trans and electronics. We know the accessories will fit the LT just like stock. The exception being the missing water pump. That seems a much smaller task than making an entirely different set work in the 3rd gen or running some hybrid setup.

I know Meziere used to make an electric pump with a built in idler, it dosnt help me except that I can easily fab a base to replace the LT's vented pump cover and instal a similar pully.

If the aftermarket had introduced a similar product I suspect people would be less inclined to buy and instal an entire LT1 acc drive.


My mistake I thought the LT pistons were flat top and my L98's were dished. I figured I can get the entire factory ballanced assembly for no extra cost at the yard. I would have to do the entire set because of the different bob weight specs for the LT1 vs the rest of the small block family. The crank is actualy the same casting as many other SBC's including many 350's and 305's, they all fit in each others place they just have different ballance specs.

Properly is a relative term, many people have made standard manifolds fit vortecs in the past before specific manifolds became common and cheap (for carb motors atleast) with vortecs likely declining in popularity with the advent of good alloy heads for the price of SD modded Vortecs and an intake I expect more back yard hackers like my self reverting to those methods. With my minimal investment and my love for hands on working it's perfectly acceptable to me. Besides the TPI manifold has slightly more material at the top of the port due to the injector bung placement than most carb manifolds. The most nagging issue with vortecs and standard manifolds isnt the exagerated miss match you have proabably seen in that stupid picture floating around, it's that there is just not MUCH over lap at the port tops.

[quote]
I still dont get why you cant use LTx accessories and everything else. If the B-bodys are popping up so much (they are) why not get everything related to the LTx?


It'll cost more and it'll take a lot longer. Are there any advantages to the LT acc drive? I know the cop cars came with high amp alts but I wont be running a big system or anything, and if I were I'd have my friends guy build me a custom piece.

I could just pull the brackets and hang the AC and PS pump out of the way during the swap then bolt it all back up without having to create new lines or even open either system. It'll proabably take time to fab a new idler but if I offered it for sale it would make the swap a lot cheaper and simpler for others.

I do want an LT1, I just dont want to swap the entire acc drive while I'm at it. I also need to keep the disty and I see no sense in swapping in a new harness when I know I'll be doing it again later.

 

I'm not going to lie, that sounds like more headache than it would be worth.

 

How so? What part would be more trouble than a normal LT1 swap?

 

You obviously havent looked over a swap car and seen just how nicely the LTx stuff fits. There is less work in using LTx stuff. You need a K-member notch for the AC (1 hr) and PS lines ($30). Hardly "a lot longer"

Who cares what the stock cop car alts put out, the alt fits the new bracket and is equal or better than your TPI stuff. BTW, I wish you luck powering the 0411 PCM with the TPI alt on the LTx engine

 

But the TPI stuff DOSNT need a notch and DOSNT need new lines and DOSE bolt up directly to the LT1.

How am I going to have trouble powering an ECU with my stock or aftermarket alt?

 

I would like to see a diagram for the belt routing.

 

Belt routing has nothing to do with the brackets and accessories physicaly fitting the LT1, They do bolt up to the motor.

I have already proposed a solution to the missing water pump pully issue. With an idler pully mounted to the face of the LT1's water pump the belt will be routed exactly like the stock TPI.

 

how would you mount the idler? I just don't see anything to mount it to.

 

how much fabrication would be required to mount the idler? to me, I would rather just notch the frame and not have to modify a water pump every time I need a new one.

 

No problem, the plate on the front of the LT pump will be replaced with a thicker steel piece that'll act as a base for the idler pully and it's shaft. The pullys are common so I would just have to cut out a piece of reasonably thick steel and a stand off for the pully's bolt to screw into.







These are the two serpentine belt setups for the TPI engines, The first is for the 88 only and the second is for the 89+. Mine is the latter but they seem all but identical as far as this thread is concerned. I posted these to show that the large upper T stat outlet that faces to the P side on the LT1 pump and the one directly below it should clear the belt. The other lines shouldnt be an issue.

The idler would just be swapped from one pump to another.

 

if you can make it work, go for it.

 

Actualy after some moer searching it's obvious the LT1 pump is way to far forward to allow a pully mounted on the front of it to line up with the rest.

I'm thinking about a pully thats still mounted off the pump bit is off to the side and reversed like on the ford modular motors. The pully would be smaller and the belt would need to be shorter to compensate.

The only reason I wouldnt just fit a much shorter belt and forget the water pump pully entirely is because I'm concerned about having the proper amount of "wrap" arount the acc pullys but the two routing diagrams each show either the PS pump being shorted on belt contact or the air pump being shorted.

The only pully I'm concerned about not having enough wrap if I threw the WP pully out entirely is the crank pully. I wouldnt wory about it at all but I intend to autoX the car and if anything is going to make the belt slip it's the power steering under high load.

I want to instal the idler so it increases the crank pully belt contact to a point where I'm comfortable. Stock it looks like it gets about 180* of contact, with the WP pully just removed it would be closer to 90*, but proabably less.

 

FWIW I've heard the frame notch can be done with a hammer.

 

That's how I did mine, a big ball peen hammer and just bent it enough to get it out of the way, only other fab I had to do was to cut the clamshell down and bend it in, weld it back and the a/c compressor fits.

The other option you can do is use vette accessories, then you don't have to worry about the notching since the vette mounts in a different spot.

 

If you get the Vette bracket, will the F body accessories bolt to it?

 

That I'm not sure about, I know that the a/c won't but not sure about the alt and p/s pump.

 

Nope

http://www.nookandtranny.com/Info_LT1.html

 

Thanks, alot of useful info there.

 

A stock Serp. setup brackets DO NOT fit a LT1. Yo have to notch the hell/ cut up the stock brackets to fit around the LT1 water pump. I know for a FACT because I did it on my LT1 to use as a spacer for my novi2000 supercharger.

There really is No way to get around it. OP should just get the Vette or fbody setup and be done with it. They are cheap enough to find these days.
http://www.cecoatings.com/images/Car...3/novi2000.jpg

 

Thanks tpi383, did you use the later model TPI brackets?

It occoured to me that running an air delete bracket with a smooth pully would give me more crank contact with the belt running on the pullys inner surface.

 

its the serpentine bracket. So 88+

 

I found this thread again searching for AC info for another person. Since I had a LT1 in the garage and a spare set of serp brackets, I figured it would be a good time to show exactly why TPI accessories are not going to work for a LT1 engine

This is a LT1 strait from a B-body about to go in my friend's 79 firebird. Notice the water pump outlets and bolt pattern unique to the LT1. Only a LT1 pump will fit there


Pass bracket. Of the 5 mounting holes, 3 lined up with the LT1. The two down near the crank snout and the one directly between the AC and smog pump. The other two arent even close. You can see the bracket covers up a good bit of the waterpump gasket surface. Grinding that area off the pump will cause a leak. Grinding it off the bracket will take out the key structural member


Drivers side. All 5 bolts line up... sort of. The head bolt holes are off by around .050" and can be opened up to accommodate. Same problems around the WP area


In short, use the LT1 stuff on your LT1 swap. The LT1 pictured, with all the accessories (minus alt), with harness, PCM, flexplate, converter, starter all tallied a whopping $150 with a 30 day warranty from the local yard. Youd be hard pressed to find a TPI serp bracket kit for that much, let alone the machining and materials cost to build some bastard setup to incorporate the two systems. Halfway swaps using either TPI or LSx control systems to run the LT1 engines are available, but dollar for dollar, LT1 stuff is always cheaper/easier

 

you know I never really understood this either...