95 Cobra: Composite intake spacer melted :(

ngiotta

Member
Jan 29, 2019
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California
Hi everyone. I was wondering if anyone here has used an intake spacer on an EGR-equipped engine. The engine was overheating from what looks to be a blown head gasket (water in the radiator bubbles with engine running), so in the process of tearing the top part of the engine down, I noticed that all of the upper plenum bolts were loose, because the $40 "phenolic" spacer I ordered off of ebay melted (badly) after just 600 miles. I notified the seller, who I'm assuming 3D printed it and he informed me that "unless EGR is blocked at the head level, every spacer on the market would melt because no spacer can withstand the exhaust temperatures". Now, I'm not sure if the spacer melting caused the overheating and/or blown head gasket, but I can't have any future melting, regardless.

I don't have any choice but to run EGR (in California) and I also have to run a spacer, due to the valve covers that I have (because I have roller rockers). Does anyone use a spacer with EGR? Is what the ebay seller told me complete FUD and he's just using cheap materials? If anyone could chime in, that'd be great. If someone has a 3/8" spacer that they run with EGR, please tell me the brand you're using. Thanks!
 
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Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
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Yes, I’ve been running a 3/8” cobra phenolic spacer for 20+ years with a functional EGR. No signs of even coming close to starting to melt.

A 3D printed spacer won’t likely last as the whole point of 3D printing is using heat to melt plastic. The good ones are machined out of a phenolic resin which do not have a melting point, but degrade at temps over 500F

I’m pretty sure this is the one I bought years ago.

 
Last edited:

WhiteCobra95

5 Year Member
May 2, 2006
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How is your intake setup? The factory '94/'95 engines (Cobra included) use an external pipe from cylinder #3 to feed the EGR valve, it doesn't pass through the lower intake. The spacer wouldn't see exhaust level temps, only heat conducted from the heads around coolant temp levels or under hood heat soak temps at a stop.

In any case, Mike is 100% correct; typical 3D printer material is not rated for engine level temps. Whoever is selling those on Ebay is really setting people up for bad issues. When we use 3D printed parts in engine development, it is usually a very high quality / expensive SLS material and in most cases it gets epoxy coated before it goes on a test vehicle or dyno engine. Even then, they don't last very long because they aren't robust to vibration.

As far as spacers go, I personally wouldn't run one on a GT40 / Cobra / Explorer / HO intake. The temperature reduction benefit is probably not measurable on a street driven car, and all of the spacers add runner length which is the last thing you want to do with the factory intakes. If you absolutely have to run one when you get your head gasket issues sorted, buy a name brand phenolic spacer like Mike suggested above.
 

revhead347

Apparently my ex-husband made that mistake.
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Have run an EGR with a spacer before. Just buy a quality one.

Kurt
 

Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
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I only run one due to clearance needs. Without it, the intake won’t clear the valve covers which are needed to clear the roller rockers. It really does nothing for heat either. After a good drive that upper intake is toasty regardless.
 

revhead347

Apparently my ex-husband made that mistake.
15 Year Member
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I only run one due to clearance needs. Without it, the intake won’t clear the valve covers which are needed to clear the roller rockers. It really does nothing for heat either. After a good drive that upper intake is toasty regardless.
Been there. Get the Trick Flow valve covers. Problem solved.

Kurt
 
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WhiteCobra95

5 Year Member
May 2, 2006
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How do the TFS covers compare to the stock SN95 covers? I was hoping to use the factory covers (re-powder coated to something nicer looking) for an engine build with shaft rollers on AFR heads. (It seems like the fit might be plausible since they could fit aluminum pedestal rollers from the factory.)
 

Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
35,977
11,917
224
Massachusetts
How do the TFS covers compare to the stock SN95 covers? I was hoping to use the factory covers (re-powder coated to something nicer looking) for an engine build with shaft rollers on AFR heads. (It seems like the fit might be plausible since they could fit aluminum pedestal rollers from the factory.)

I tried the factory ones and it was no dice. I’m running the crane gold 1.6 RRs. Eventually swapped to the Ford racing valve covers which fit perfectly but required the spacer.

I’m really not concerned with every single HP. Using a spacer doesn’t bother me
 

revhead347

Apparently my ex-husband made that mistake.
15 Year Member
Jun 14, 2004
8,793
1,457
214
41
Acworth, GA
How do the TFS covers compare to the stock SN95 covers? I was hoping to use the factory covers (re-powder coated to something nicer looking) for an engine build with shaft rollers on AFR heads. (It seems like the fit might be plausible since they could fit aluminum pedestal rollers from the factory.)

Nothing beats stock for quality. I had a spacer on my intake for years until I saw the Trick Flow ones on Adams95GT on here. It was a good move for me personally, because I use stud mount rockers. The TFS ones you have to drill a hole for the filler neck, and it's no where near as rigid, or functional as the factory neck. Your Cobra comes with pedastal mount roller rockers that were made by Scorpion I believe. I don't think you will get stud mount rockers under the stock valve covers. On the engine I built for the Cobra I used the factory rockers on X303 Ford Heads with the stock valve covers, and it worked fine. If you can reuse the factory rockers, and the factory valve covers, that's the route I would take.

Kurt