Is there a possibility that the Lt1 accessory brackets will bolt onto a gen1 sbc?
This seems like the easiest way to run an electric pump and retain serpentine belt. The only other questions that would make or break this idea is the balancer/pulley. Will they bolt onto a gen1 sbc hub or not?
Now if those questions are all a yes, which Lt1 accessory's will bolt up? F-body/Y-body/B-body?
I have a feeling nobody has even tried and if the balancer/pulley doesn't work with little effort I won't even bother. Just figured I'd see if it was possible considering all of these Lt1's that are making their way into the j-yards... .

 

JP,

I just tried the opposite of this and I didn't have much luck. I have an '96 LT1 laying around and I was trying to figure out a way to attach my Gen I acessories to it. It can be done with a spacer plate and a bolt hole adapter. I suppose the same thing can be done going from Gen I to Gen II. I can snap some pics for you this weekend when I get to my shop. I can also check on the balancer pulley as well. I do know that the hub sticks out much farther on the Gen II's so that will require some attention when combining the two.

 

Eventhough the LT1 is a "small block", the holes are the front of the block are completely different. The only thing the block has is common is the motor mount location, trans bolt pattern, and same internal dimensions.

 

Aren't the heat temp sensors in the same locations, knock sensors same spot, same thread, oil routing/ports on the back, oil pan, starter... I know the water pump is different but I thought the accessory bolt holes would be very similar.
Shifty, if you could snap a couple pictures that would be awesome. Maybe even measure out the distance between some of the holes. I've got my gen1 setup here off the engine that I'll measure up to check out.

 

the front of the motor is totally different concerning the accessories. The only thing you can do is use an aftermarket setup or use a corvette assembly.

 

JP,

Here are some pics that may help. I was in a hurry so they may not help much. You should be able to see where the bolts holes for the gen II accessories are in relation to your Gen I.






Right side


left side

 

It will bolt up just fine, the points where they bolt up are exactly the same for the accessories, isnt this fun when those who dont know what they're talking about go acting like they do and confuse people ?

The main thing disabling the use of 88-92 serpentine accessories on an LT1 is the lack of a belt driven water pump, the only thing needed to physically get the brackets on is some grinding of the a/c side bracket I believe it was, to clear part of the water pump, yes I have done it before, it was quite a bit of grinding too.

I cant guarantee that the aftermarket water pump you end up with will clear the LT1 brackets, but other than that it will bolt on and work fine, you'll just need to add a timing mark to the LT1's balancer, and you may want to check on sending the hub to have a keyway slot added if you arent going to use an aftermarket, since they dont have one stock.

 

I could not get my accessories to bolt to that LT1. Pehaps I had an allingnment issue and need to go back and re-evaluate. I could only get two bolts in at the time because the bracket was hitting the chain cover. Never did I claim to have the answer without having tried it myself. I said I didn't have much luck. You are too quick to assume we make blind assumptions with no merit. I appologize if I have confused anyone. I assure you that was not my intent.

Thanks for the clear-up though. It appears that I need to go back and try things again. This is my first LT1 swap and I appreciate the input from those, such as yourself, that have done it numerous times.

 

You will be able to use the knock sensor and temp sensor locations and if the starter has straight aligned holes then i would have to say it will bolt up the say way (maybe flywheel issues if you're not using the LT1 flywheel, 168 tooth I think). The LT1 even has the threaded hole for a mechanical clutch linkage above the oil filter. But, like I said, the front of the motor is setup only for the accessory bracket for the F-body and the Y-body. the B-body uses the same bracket as the F cars do. I am sorry you received bad information from somebody that would rather gind and alter parts than do it correctly the first time. And if something happens then you don't have to buy another part and grind the brand new part just to get it to fit.

 

Shifty, I was not implying you were throwing around misinformation, only this 1981LT1 character, which he is still doing, the 88-92 serpentine bracket can be bolted to an LT1 with a good deal of grinding. The LT1 bracket on a gen 1 sbc which is what JPrevost wants to do will bolt up, as I stated before and 1981LT1 wants to argue when he is in fact still wrong.
JPrevost you can bolt the setup on, the center mounting bolt hole doesnt exist on the gen 1 block, and there is no way that I know of to reasonably gain that one back, one of the head bolts and one of the lower bolts are in the correct location, the left bolt if you are facing the front of the engine, which gives you 2 of the 4 that directly line up, another you can drill and tap in the head since its in a slightly different spot.

 

"which gives you 2 of the 4 that directly line up, another you can drill and tap in the head since its in a slightly different spot."

Drilling and tapping does not constitute a perfect fit. Why would you bolt on an accessory system that only a couple of the holes will line up?

 

Thanks for the explanation . That makes more sense now.

 

That's how my setup is now. I removed the metal rod bracing and didn't use 1 of the 2 lower points for a year (lost a couple bolts).
I don't care if it's not a perfect fit. I just wanted to know if it would bolt up. If it does, I'm 90% there.

The Lt1's crank hub doesn't have a keyway? So why would I need to get one cut? How is it secured to the Lt1 crank snub if no keyway? I'm a little confused.

 

The f-body balancer was not keyed for the crank snout keyway. It is a simple press on unit. The Y-body did have a keyed balancer to handle the extra torque and hp.

 

I think you're wrong.
http://www.automotiverebuilder.com/ar/ar99928.htm
From that source it makes it clear that the Lt1 snouts where all the same... no keyway for the hub. Which makes sense since the Y-body's didn't exactly make much more HP and their accessories can't be that much different than the F-body and B-body's.
The source above then goes on to say that the later OBD-II Lt1's used a slightly different key that was just enough to index the crank pickup wheel.
So I would need to remove the key, install the hub, install balancer, figure a way of securing the brackets better to the engine and I'd be set... to then check that my water pump fits .
Thanks for the help so far.
Almost forgot; from another source I'm told the hub is shorter on the 96-97's because of the longer key. Does anybody think that's a big deal if I use a 96-97 hub vs the earlier longer versions?
edit: Just found this http://www.go-fast.org/z28/damper.html

 

The f-body balancer was not keyed for the crank snout keyway. It is a simple press on unit. The Y-body did have a keyed balancer to handle the extra torque and hp.

 

Dude, you need to get your facts straight

Also

None of the hub assemblies had a keyway cut into them. The keyway was used for the timing gear.

The Y-body cars didn't make more torque and hp than the F-body engines, I don't know where you are getting your info from, but it isn't right.

 

Read some MORE... apparently the Y-body hub's put the balancer/pulley 16mm further away from the engine.

 

Now to talk about the balance.
Lt1's use the balancer to balance the rotating assembly (which is lighter than a gen1). So what to do?
My flexplate, like most gen1's from 87-97, have a weight to indicate external balancing. From Lt1 sources it's the same way, and this might be why the Lt1 T56 flywheels bolt right up without any vibration issues .
But here's the strange part; the Lt1 balancers have weights in them to balance the rotating assembly and aren't our gen1's using neutral balancers? Can the weights simply be pulled off of the Lt1 balancer or machine work or do I need the weighted balancing?

 

The balancers are made different to make up for the light weight powdered metal rods used. The crank is also balanced for them as well, thus the reason they say not to swap the cranks up because you could end up with a bad vibration issue. I'm going to go out on a limb and say I wouldn't use the LT1 balancer for this reason, but go with one of the fluidampr for the LT1.

As for weights, my LT1 balancer doesn't have any weight on it, but is drilled to lighten it up and keep it in balance with the crank.

 

My engine is the 330hp crate bought in 2001. It has PM rods... now I'm really confused.

 

Nope, LT1's use a neutral balance dampener.

What causes confusion is that many of them DO have pressed in weights in the holes in the inner ring. GM added those on an as-needed basis to trim out individual rotating assemblies. However, that should not be taken as an indication that it's an externally balanced engine, because it's not!

Go examine a group of bone stock factory LT1's, and you'll find that some have weights, and some don't. Also, when replacing a dampener on an LT1, you are supposed to transfer any weights present in the factory dampener to the new one.

Now, to clear up some of the other stuff.

LT1's use the same flexplate as 1-pc RMS Gen I SBCs. That weight is to compensate for the difference in the rear crank flange compared to the old 2-pc RMS crank. I kind of like the phrase "semi-internal balance", although it never caught on.

B-body and F-body LT1s use *different* accessory brackets, contrary to what was previously stated.

No factory GM LT1 or LT4 torsional dampers (I try not to call them "balancers" because they aren't!) are keyed, period. It's a press-fit only -- which works fine unless you add a belt-driven supercharger or something similar, in which case they tend to spin. Aftermarket keyed hubs are available, and the crank does have the normal keyway already present. Keep in mind that GM had no reason to worry about having to have the damper installed *exactly* right, since you don't have to set ignition timing on an LT1 the way you would on an earlier SBC.

B-car and F-car LT1 use the same damper, but with different length hubs. The Y-car used a different damper, but with the same hub as the F-body. Also, the OBDII hubs are about .100" shorter than their OBD I counterparts to account for the extra thickness of the crank reluctor. So, you have four different hubs, and three different factory dampers (LT4 being the third) to choose from. Confusing enough?

As far as the original question, I've never tried it, but I see no reason why LT1 accessories couldn't be made to work on a Gen I SBC. Using the appropriate LT1 hub/damper combo to match the accessory bracket would make it a lot easier.

 

Well, I will be the first to admit I was wrong. You are correct in that the accessory bracket is different for the B and F body. And as for the keyed crank, I was confused and spoke too soon when I said the hub was keyed aslo. Only the crank is machined for the key.

And yes, with some proper thought and measuring, the accessories could be made to work with a non LT1 sbc.

Sorry.

 

HELP>.......OK I just went out and looked at my crate LT1 that Im putting together to go into a 89 camaro......

I bougt a LT1 hub to go onto the crank snout.....WELL when i went to install it I noticed that there is IN FACT a keypin on the snout of the crank......I see also where there is a keypin coming out for the timing gear......then another keypin out of the snout......SEE PIC...is this correct?


this is installed on my LT1, I know it a LT1 I checked the casting numbers on the block and it is a 96 LT1