Technical N54 Phenolic fibre fuel rail gaskets.

martymil

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So I've been testing the phenolic fibre washers between the fuel rail and head and rail and nut.

I converted from bolts to studs to make things a lot easier to install

Measuring the temps on a stock fuel rail was between 200f to 210f at idle after a cruise which is the same temp as the head.

With the phenolic washers

Cruise temp was 128f to 140f

Spanking temp was 158 to 165 with head temps of 218f

I'm only working with surface temps of the rails and lines and the difference is between 45f to 72f.

Not bad for under a dollar worth of gaskets and it was tested with the engine cover on, running an aftermarket vc the temps are even lower.

Is there any benefit, haven't tested that properly yet as we are in lockdown except when I drive to work.

But going of past experience lower temps help with cylinder cooling, resistance to engine timing drops and makes more hp.

How much benefit there is I don't know but for less than the price of a bottle of coca cola I think its worth it.

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Popeye

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So I've been testing the phenolic fibre washers between the fuel rail and head and rail and nut.

I converted from bolts to studs to make things a lot easier to install

Measuring the temps on a stock fuel rail was between 200f to 210f at idle after a cruise which is the same temp as the head.

With the phenolic washers

Cruise temp was 128f to 140f

Spanking temp was 158 to 165 with head temps of 218f

I'm only working with surface temps of the rails and lines and the difference is between 45f to 72f.

Not bad for under a dollar worth of gaskets and it was tested with the engine cover on, running an aftermarket vc the temps are even lower.

Is there any benefit, haven't tested that properly yet as we are in lockdown except when I drive to work.

But going of past experience lower temps help with cylinder cooling, resistance to engine timing drops and makes more hp.

How much benefit there is I don't know but for less than the price of a bottle of coca cola I think its worth it.

View attachment 37058
This was done on my car as most little mods that Marty has done have all been super beneficial and I must say I found it hard to believe that a couple of washers would make so much difference in heat transfer but I saw it with my own eyes before and after remember all these little things eventually add up in the end thanks again Marty 👍
 

doublespaces

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Measuring the temps on a stock fuel rail was between 200f to 210f at idle after a cruise which is the same temp as the head.

With the phenolic washers

Cruise temp was 128f to 140f

Spanking temp was 158 to 165 with head temps of 218f

I'm only working with surface temps of the rails and lines and the difference is between 45f to 72f.

So, there is a delta I get it and that is good. But if we take the best/worst of what you gave, I think it raises more questions such as why is there a nearly forty degree delta while parked in the same conditions with the same test? Which measurements were on the fuel rail vs fuel lines, is this where the variance comes from or something else? Going by what you're giving, someone could potentially see 82 degree temp drops on the fuel rail at idle with these things on.

Before:
200 -> 210 parked
173 -> 212 cruising
203 -> 237 boosting

After:
128-165 parked
128-140 cruising - How did you measure?
158-165 boosting

I'm not saying you're lying or being deceptive, just wanted to get a better feel for what is occurring.
 
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martymil

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As the car sits.and not much fuel is flowing and even though you have the washers the engine cover along side the vc heats the fuel rail and lines but not as much when directly bolted to the block.

I only posted the results from a stock setup as thats what most will run on their cars.

Now an aftermarket vc and ceramic coating will skew the results even more for the better.

Also the variance is also coming from the hpfp as in low volumes it tends to heat up a little.

I'm sharing this as its a benefit to the community the more you heatshield certain items the better the benefit.

Just the washers have a huge impact.and its then single best bang for buck mod.

Even at its worst it has a huge difference from stock and can only be beneficial no matter how you want to look at the results.

All surface temps where taken on the 1st cylinder with engine cover on.

The head was 200f and above at all times and so was engine water/oil remps.

Measured with a laser temp gun and all temps where checked three times.

Someone else that has access to testing equipment can double check my results and I strongly welcome it.

I even seen a significant temp drop on the injector surface temp on my own setup, but I can't test that with a engine cover on.

This will definetly help with the longevity of injectors

There is just to many setups to say this will be the result you should see, its a good starting point and basically costs nothing.

Until the lock down is lifted there is not much I can do to offer anything else.
 
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doublespaces

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Have you explored any active cooling options? I know you have but anything interesting?
 

martymil

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To make the things easier for you guys here is the parts you need

8 x phenolic washers either m8 or 5/16
4 x m8 or 5/16 stainless or equivalent washers
4 x n54 turbo manifold studs
4 x inlet manifold nuts
1 x Tube of anti-seize

1hr labour including a six pack on a lazy sunday afternoon.

Makes it super easy install

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doublespaces

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So its a conversion from bolts to studs as well. Is there something stopping a person from just sticking the washers to the back of the fuel rail mounting tabs with some sort of adhesive and using the factory bolts?
 

doublespaces

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Yeah, I can see how it would be frustrating to get all 8 of those buggers on there with the bolts pointed the wrong way.
 

JohnDaviz

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Can you give me input on the n54 studs? Which size and length are they?
 

martymil

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they are the n54 turbo manifold studs and inlet manifold nuts

Most shops that do turbo swaps will have hundreds laying about as they are one time use for turbos but can be reused on the rail.
 

JohnDaviz

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oh now that you repeated it i figured there is the term turbo manifold used.. thanks!

Was a bit blind :D Guess will get them cheap on ebay.