Question for Tom DeWitt or anybody who knows..
08-21-2003, 04:07 PM
#1
Team Owner
Thread Starter
Question for Tom DeWitt or anybody who knows..
On the typical old iron manifolds for SBC, the rear water pasages are connected together, but just as a crossover, apparently....
on a Pontiac they are NOT, indeed they go nowhere, except #8 passage is a pipe hose fitting to the heater core....and does NOT crossover at all....
NOW on examining the L98 injection setup when I installed it on my car, I just blocked off that small line from the rear water crossover passage by plugging the hole....
NOW, I noticed a stock '86 vert vette (aluminum heads) has that connected to the input of the pump...only about 3/8 line....
so at this point I did the same....
the question is....why is that there?? and does it make any differance??? does it tend to even out the water flow a bit?? or just for super hot conditions when it may steam?? in other words...WTF is going on....???
GENE
on a Pontiac they are NOT, indeed they go nowhere, except #8 passage is a pipe hose fitting to the heater core....and does NOT crossover at all....
NOW on examining the L98 injection setup when I installed it on my car, I just blocked off that small line from the rear water crossover passage by plugging the hole....
NOW, I noticed a stock '86 vert vette (aluminum heads) has that connected to the input of the pump...only about 3/8 line....
so at this point I did the same....
the question is....why is that there?? and does it make any differance??? does it tend to even out the water flow a bit?? or just for super hot conditions when it may steam?? in other words...WTF is going on....???
GENE
08-31-2003, 12:07 PM
#5
Re: Question for Tom DeWitt or anybody who knows.. (mrvette)
Gene:
The crossover on the rear of the old manifolds did nothing. Old thinking that didn't accomplish anything.
The reason GM puts the line on is to help bleed off any air in the system. With the line going back to the inlet on the pump any coolant in the line bypasses the the path to the radiator so the line has to be kept small to limit the amount of coolant flow through it.
[Modified by Pete79L82, 11:08 AM 8/31/2003]
The crossover on the rear of the old manifolds did nothing. Old thinking that didn't accomplish anything.
The reason GM puts the line on is to help bleed off any air in the system. With the line going back to the inlet on the pump any coolant in the line bypasses the the path to the radiator so the line has to be kept small to limit the amount of coolant flow through it.
[Modified by Pete79L82, 11:08 AM 8/31/2003]
08-31-2003, 01:58 PM
#6
Team Owner
Thread Starter
Re: Question for Tom DeWitt or anybody who knows.. (Pete79L82)
I thought it may have helped with even ing out the cooling for the rear two cylinderd by adding some flow on the downside of them....
thereby allowing leaner mix and more spark....for the DPFI systems....
only reasoning I could think of for it's existance....so it's of no value to hook up??
GENE
thereby allowing leaner mix and more spark....for the DPFI systems....
only reasoning I could think of for it's existance....so it's of no value to hook up??
GENE
08-31-2003, 04:46 PM
#7
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Re: Question for Tom DeWitt or anybody who knows.. (mrvette)
some people connect the rear outlets to the thermostat housing.
Aparently it does help a little cooling wise in critical applications. i.e high rpm, high load situations like circle track...
But supposedly not necessary or very helpfull for the street
Aparently it does help a little cooling wise in critical applications. i.e high rpm, high load situations like circle track...
But supposedly not necessary or very helpfull for the street
