914 conversion questions

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glovebox
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914 conversion questions

Post by glovebox »

So installing a 2.2t with carbs into my 914 1.7.
So one fuel question and one electrical. (For now ;) )

So reading on different sites are all saying you don't need a fuel return if your running original zeniths. But I have a return pipe as standard anyway, so should I be better to make use of it?? I am running a low pressure Holley pump with a pressure regulator for adjustment but also is a nice T piece to run to both carbs. One in two out. If I go with a return, where would you put it ??

Also moving the battery to the front hood. So now have a nice sealed battery and up sized cable plus battery box. So thinking of putting the battery passenger side, up against the corner. So where to run the cable?? I'm thinking through the bulkhead into the car along the sill line out the rear bulkhead but not sure if I should run it under the car or through the engine bay? I guess both introduce heat issues.

Many thanks in advance

Regards Mark.
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Jonny Hart
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Re: 914 conversion questions

Post by Jonny Hart »

There's quite a bit of room in the centre tunnel. Plates fore and aft for access.

My 914 is electric and I've just run two heavy gauge cables in place of the original fuel lines. Bit of a fiddle, but doable. You'd need another hole and grommet at the back. Drill the the front bung for an extra cable. It is under the fuel tank - I don't have one of those! :)
911hillclimber
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Re: 914 conversion questions

Post by 911hillclimber »

No need for a return to tank after the carbs IF the pressure is set right.
Too high and the pump will blow past the float needle = flooding out of the carbs.

If you have one and don't use it be sure to plug it off, it is a huge tank vent otherwise.

I have a 3.2 engine on carbs (PMO's) with a carb pressure pump, fed via an in-line filter from the tank, to a quality pressure regulator, to a Tee to each carb and that's it.

Tank return is plugged-off, tank vented at the neck to atmosphere.
73T 911 Coupe, road/hillclimber 3.2L
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jwhillracer
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Re: 914 conversion questions

Post by jwhillracer »

Why not put the battery in the rear? Much less wiring and easier to arrange.

JW
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1963 Porsche 109 Junior
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914 KEV
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Re: 914 conversion questions

Post by 914 KEV »

glovebox wrote:Also moving the battery to the front hood. So now have a nice sealed battery and up sized cable plus battery box. So thinking of putting the battery passenger side, up against the corner. So where to run the cable?? I'm thinking through the bulkhead into the car along the sill line out the rear bulkhead but not sure if I should run it under the car or through the engine bay? I guess both introduce heat issues.
Why???

The battery location in the engine bay is in a convenient place, only short runs to the starter motor and alternator.
By moving the battery it doesn't stop water still getting in the engine bay!
Nowadays batteries are better and you are using a sealed battery.
Taking time every now and again to clear the drain holes on either side of the front engine shelf to stop the silt building up and letting the water out which also evaporates when the car is used.
A full battery cover stops water getting onto the battery and placing a yellow battery mat under the battery which will turn red if there is any sign of a battery acid leak.
On my 914s I have used Bosch Silver Battery's with a full battery cover and a battery mat for years and I have never had a problem of a battery mat turning red.
914 Daily driver since 1990
glovebox
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Re: 914 conversion questions

Post by glovebox »

911hillclimber wrote:No need for a return to tank after the carbs IF the pressure is set right.
Too high and the pump will blow past the float needle = flooding out of the carbs.

If you have one and don't use it be sure to plug it off, it is a huge tank vent otherwise.

I have a 3.2 engine on carbs (PMO's) with a carb pressure pump, fed via an in-line filter from the tank, to a quality pressure regulator, to a Tee to each carb and that's it.

Tank return is plugged-off, tank vented at the neck to atmosphere.
Thanks that's great! Makes it easier to plumb in with what I've got as well :)

Best regards Mark
glovebox
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Re: 914 conversion questions

Post by glovebox »

Jonny Hart wrote:There's quite a bit of room in the centre tunnel. Plates fore and aft for access.

My 914 is electric and I've just run two heavy gauge cables in place of the original fuel lines. Bit of a fiddle, but doable. You'd need another hole and grommet at the back. Drill the the front bung for an extra cable. It is under the fuel tank - I don't have one of those! :)
Thanks Jonny yes I had thought that. Not sure about sharing the tunnel with fuel lines ??

Regards Mark
911hillclimber
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Re: 914 conversion questions

Post by 911hillclimber »

+1 for Bosche Silver Batteries, soooo much better than anything else I've had in my '73 911.
73T 911 Coupe, road/hillclimber 3.2L
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
glovebox
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Re: 914 conversion questions

Post by glovebox »

911hillclimber wrote:+1 for Bosche Silver Batteries, soooo much better than anything else I've had in my '73 911.
Ok I went for a Odyssey extreme in the end :)
glovebox
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Re: 914 conversion questions

Post by glovebox »

914 KEV wrote:
glovebox wrote:Also moving the battery to the front hood. So now have a nice sealed battery and up sized cable plus battery box. So thinking of putting the battery passenger side, up against the corner. So where to run the cable?? I'm thinking through the bulkhead into the car along the sill line out the rear bulkhead but not sure if I should run it under the car or through the engine bay? I guess both introduce heat issues.
Why???

The battery location in the engine bay is in a convenient place, only short runs to the starter motor and alternator.
By moving the battery it doesn't stop water still getting in the engine bay!
Nowadays batteries are better and you are using a sealed battery.
Taking time every now and again to clear the drain holes on either side of the front engine shelf to stop the silt building up and letting the water out which also evaporates when the car is used.
A full battery cover stops water getting onto the battery and placing a yellow battery mat under the battery which will turn red if there is any sign of a battery acid leak.
On my 914s I have used Bosch Silver Battery's with a full battery cover and a battery mat for years and I have never had a problem of a battery mat turning red.

Ahhhh Kev..... I knew you would say that ! :)
And yes I know your right. ....
But :) I would like to create or at least give the feeling of more space in the engine compartment:)
Plus I have to rewrire a lot anyway. What with new engine and removing the engine relay board.
And I guess I've have ruined all chances of originality anyway??
Plus I have a front trunk I never use ! ;) lol

What do you think ?

Best regards Mark
Mr Pharmacist
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Re: 914 conversion questions

Post by Mr Pharmacist »

put the battery in the rear boot? I've seen that on 914world before
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rhd racer
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Re: 914 conversion questions

Post by rhd racer »

My battery is in the rear boot too. Easy to run the cables and cut offs if required.

I too had a return line but don't use with carbs. Unlike Graham, I run a low pressure pump, via a filter, to a T. This means that you can eliminate the pressure regulator.

The reason why PMO advocate them is seemingly that most conversions to carbs are for CIS or EFI engines that have or have had high pressure fuel pumps. I had already had a host of problems with the HP pump on CIS so was not sorry to see it go! I took advice, and it seemed that pumping the pressure to a very high pressure then throttling it down is somewhat pointless, and only introduces the chance of a leak of fine mist of fuel near a heat source (most fit the regulator in the engine bay).

Just my two-penne th!

Cheers
Wayne
93 964 C2
99 Boxster 2.5 > 3.4 hill climber

71 914/6 3.0 - gone

'You see Paul, hill climbing is like making love to a beautiful woman. You get your motor running, check your fluids, hang on tight and WHOA..30 seconds later it's all over!' Swiss Tony
jackstowers
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Re: 914 conversion questions

Post by jackstowers »

glovebox wrote:
914 KEV wrote:
glovebox wrote:Also moving the battery to the front hood. So now have a nice sealed battery and up sized cable plus battery box. So thinking of putting the battery passenger side, up against the corner. So where to run the cable?? I'm thinking through the bulkhead into the car along the sill line out the rear bulkhead but not sure if I should run it under the car or through the engine bay? I guess both introduce heat issues.
Why???

The battery location in the engine bay is in a convenient place, only short runs to the starter motor and alternator.
By moving the battery it doesn't stop water still getting in the engine bay!
Nowadays batteries are better and you are using a sealed battery.
Taking time every now and again to clear the drain holes on either side of the front engine shelf to stop the silt building up and letting the water out which also evaporates when the car is used.
A full battery cover stops water getting onto the battery and placing a yellow battery mat under the battery which will turn red if there is any sign of a battery acid leak.


On my 914s I have used Bosch Silver Battery's with a full battery cover and a battery mat for years and I have never had a problem of a battery mat turning red.

Ahhhh Kev..... I knew you would say that ! :)
And yes I know your right. ....
But :) I would like to create or at least give the feeling of more space in the engine compartment:)
Plus I have to rewrire a lot anyway. What with new engine and removing the engine relay board.
And I guess I've have ruined all chances of originality anyway??
Plus I have a front trunk I never use ! ;) lol

What do you think ?

Best regards Mark
What is it you need extra space in the engine compartment for? The unused front boot is where to transport anything you don't want warmed up by the exhaust and tainted with hot oil fumes from the rear boot like your grocery shopping.
David

1973 914 zambezi green
1972 911T (lhd 71E engine)sadly sold
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