Homer

iTrader: (1)

I've heard plenty about how the LT1 is so great because it uses reverse flow cooling which flows to the heads first etc... if this is such a great plan then how come the LS1 uses the old sbc flow cooling style?

JoelOl75

Probably because people didn't understand how to bleed the air out of them...causing problems/overheating and possibly damage so GM scrapped it. Thats what I figure but don't know for sure.


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'88 Camaro RS 2.8L
'88 Formula 350 (Too many mods to list...)

Homer

iTrader: (1)

Bleed the air out of them? What are you talking about?

Vader

Homer,

The reverse-flow cooling systems are a mother-bear, PITA, S.O.B., !#%@¢¿÷$² to refill. The design of the system tends to trap air in pockets in the heads, and underfilling can cause localized hot spots and engine damage. I've got two LT1s and they are provided with air bleed valves to assist the bleeding, but are still no picnic.

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Later,
Vader
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"I'm'a do Things My Way - It's My way or the Highway."
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Homer

iTrader: (1)

Hmm... this makes the LT1 a little less ideal for my dream motor swap.
As an owner of LT1's, what can you tell me about aftermarket parts? The small block chevy has been blessed as the most modded motor, and therefore most supported by the aftermarket. I know the LT1 heads, intake, and cooling are gen II sb specific and incompatible with the legions of sbc parts out there (though not the cam or bottom end). Are aftermarket replacements for parts specific for the LT1 more expensive and/or not as diverse as the ol' sbc? I've noticed a lot more TPI's retrofitted to older cars than LT1's, is this why?

Vader

Homer,

The most unique parts of the LT1 are the water pump, timing set, oil pump drive, heads, and distributor. Almost anything else is virtually the same as the "standard" SBC first generation engines.

The bottom end dimensions are identical to the SBC Gen I engines. The valve train is the same except for the timing set and water pump / distributor drive provisions.
The stock con rods are forged powdered metal, which can interchange with other SBCs. The exhaust manifolds are the same dual pattern as most later SBCs like the L98. Even the basic head design is the same as the SBC Gen Is except for the cooling and lack of EGR passages. The induction system is unique to the engine family, but is a lot like the Accel min-ram in function and theory.

You probably pegged the big reason the older engines are more commonly used in retrofits. There are not nearly as many cam, head, and intake possibilities for the LT1/4 as for a Gen I SBC. Not that there aren't any options, just not nearly as many.

The other consideration is the control system for the injection and ignition are more complex than the older TPI and TBI engines. It's a bit more work to fit an LT1 into a car not designed for it, but I have an acquaintance who installed one in a '37 Chevy coupe and is doing the same in a '41 convertible. It just takes more effort, and probably $$$.

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Later,
Vader
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"I'm'a do Things My Way - It's My way or the Highway."
Adobe Acrobat Reader

99Hawk120

Actually the horror stories I hear about the opti-spark are the reason I stay completely away from the LT1. When I went to buy a newer F-body it wasn't even an option for me.

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"Beware he who would deny you access to information, for in his heart, he dreams himself your master"

'84 Black Camaro ZZ4 M5 (V-6 in a former life) -- street beast
'91 Medium Blue Metallic Z28 A4 (UB-HSTRY's old ride) -- currently broken
'99 Navy Blue Metallic Firehawk #120 M6 (99.44% stock) -- daily driver