914-6 engine rebuild/upgrade options - opinions?

[911pcars]

Originally Posted by JmuRiz

Henry, I know you did this setup on a 3.0 a while back...would this work with a GT engine lid? I’m looking for ideas on my future 2.7 similar to your specs listed in post #4

Front oil cooler: pressure side or not?

Hmm. That seems like the same issue as a Kool-Collar install; an "oil cooler" product sandwiched around the engine oil filter.

The air path for absorbed and rejected heat from these coolers is directed into the air cooling stream instead of dumping heated air outside the vehicle. This raises the temperature of the ambient temperature air flow, not ideal.

Sherwood

[Henry Schmidt]

Originally Posted by 911pcars

Hmm. That seems like the same issue as a Kool-Collar install; an "oil cooler" product sandwiched around the engine oil filter.

The air path for absorbed and rejected heat from these coolers is directed into the air cooling stream instead of dumping heated air outside the vehicle. This raises the temperature of the ambient temperature air flow, not ideal.

Sherwood

You are correct..It's not the best option especially if you spend a great deal of time sitting in traffic. But if you keep it moving this set uo does reduce engine oil temperatures which does most of the cooling in a 911 engine.

[911pcars]

Henry, understood and acknowledged. It’s also a major project to install a front cooler with its plumbing in the tight space constraints.

[mepstein]

Originally Posted by 911pcars

Henry, understood and acknowledged. It’s also also a major project to install a front cooler with its plumbing in the tight space constraints.

We make some replica GT hard lines and some other 914-6 conversion parts that make it easier. It's not usually space constraints but the cost that holds people back. Unfortunately, theres no getting around the fact that quality parts and labor cost money. 914-6Werkshop dot com

[Cairo94507]

mepstein hits the bullseye as expected. If you are going to add an oil cooler to a 914, do it the way the factory did. This is the way I did mine along with the PMS oil cooler and thermostat. The car never overheats and I am running a 3.2 in the CA Bay Area where we see 105 degrees in the summer with lots of traffic.

[gereed75]

Henry,

So the Rx 7 cooler has a built in TStat? Any reason this would not work plumbed in to the scavenge side of the original oil system?

Seems that would be a most simple system. Scavenge outlet plumbed into this cooler with built in thermostat controlling flow to the cooler.

Agreed that this cooler location is not optimal, but my gut instinct engineering feel is that increases in charge temp would be small and oil cooling effective.

[Henry Schmidt]

Originally Posted by gereed75

Henry,

So the Rx 7 cooler has a built in TStat? Any reason this would not work plumbed in to the scavenge side of the original oil system?

Seems that would be a most simple system. Scavenge outlet plumbed into this cooler with built in thermostat controlling flow to the cooler.

Agreed that this cooler location is not optimal, but my gut instinct engineering feel is that increases in charge temp would be small and oil cooling effective.

The oil filter is fed from the scavenge side of the oiling system. Pulling it off a sandwich plate under the filter is essentially what the GT cars did. They just build a sandwich plate and thermostat into the filter housing.
By using a sandwich plate as I described, the entire project is a bolt on accessory.
Modifying the deck lid is the only permanent alteration. That's why sourcing another deck lid makes sense. Paint it to match, save the original and you win.
The 914-6 is climbing in value.....mess with it at the cost of originality and resale value.

[911pcars]

For a full flow cooler, the inlet and outlet ports are typically replaced by larger weld-on adapters (e.g. AN-12, -16).

[Mark Henry]

Originally Posted by 911pcars

For a full flow cooler, the inlet and outlet ports are typically replaced by larger weld-on adapters (e.g. AN-12, -16).

^ this with the Rx7 cooler, the ports are a bit on the small side. Also many cut one or both ends off, then welded plates onto the end, made a matching plate to bolt on that has the fitting. They can then unbolt the plate for cleaning the cooler. This mod deletes the RX7 thermostat, you use an external t-stat.

The MB unit you can use as is, a lot less work.

[4CamGT]

Originally Posted by Henry Schmidt

More air is always better. We used the small hole technique in an attempt to direct suction from the fan through the cooler.
I used this same technique on my street six but I did notice higher engine tempts on hot days at idle. Full throttle and cruise the cooler worked but sitting still was a challenge.

This is my 914-6. I bought it from the previous owner who had the 3.2 installed with the RX7 cooler. It ran great but aesthetically I wanted it to look stock factory Porsche. I worked with Ed Palmer at KundenSport. Fortunately I got the uncut original engine lid. We installed the original 914-6 fan shroud and air box and got rid of all the non-stock looking parts. We then installed two new 930 coolers w/fans below the rear floor w/o cutting or drilling by using existing mount locations using fabricated brackets etc. I had Harvey Weidman make a pair of R7’s (w/205/55R15) for the front and non-existent R8’s (w/225/50R15) for the rear. We dialed in the gearbox with new bushings. My 6 now runs all day long at 180 to 200 degrees, shifts and drives amazing. The original #’s matching motor is stored safely in a crate. Not criticizing any of the previous work as it gave us a head start and a good core to improve on.

[4CamGT]

A few more photos.

[stevesc_us]

Nice to see my old 6 looking so good! Didn't know you had Harvey make you a set of 8R's for the rears. Nice touch. Thanks for posting Freeman.

[JmuRiz]

Wow, amazing look and solution.

[Henry Schmidt]

Wow! I haven't seen that car in over 20 years. Glad to see it's still running well.
I used that style lid cooler on my own 914/6 with multiple engines for decades. No cooling issues even on 100+ days blasting out to Vegas.

[4CamGT]

Originally Posted by Henry Schmidt

Wow! I haven't seen that car in over 20 years. Glad to see it's still running well.
I used that style lid cooler on my own 914/6 with multiple engines for decades. No cooling issues even on 100+ days blasting out to Vegas.

Henry, the main reason I changed it was I wanted a more hidden and discreet factory look. Fortunately Steve had the original uncut engine lid from the car with its original paint. Your solution was clever and effective. The two factory 930 coolers with fans it now has fits beautifully under the rear floor above the headers. It does a really good job of cooling. Not cheap though!! In the paperwork I got with the car was a receipt from you discussing it being dyno’d for around 6 hours before it being installed. The original Ebay ad mentioned 245hp. Might you still have the dyno sheet? Engine has never been opened up. It’s an 85 Carrera long block. It had 71K miles on it when you installed it. I estimate it has about 90K miles on it now. It doesn’t leak any oil. Starts on the button hot or cold!

[4CamGT]

Originally Posted by 4CamGT

Henry, the main reason I changed it was I wanted a more hidden and discreet factory look. Fortunately Steve had the original uncut engine lid from the car with its original paint. Your solution was clever and effective. The two factory 930 coolers with fans it now has fits beautifully under the rear floor above the headers. It does a really good job of cooling. Not cheap though!! In the paperwork I got with the car was a receipt from you discussing it being dyno’d for around 6 hours before it was installed. The original Ebay ad mentioned 245hp. Might you still have the dyno sheet? Engine has never been opened up. It’s an 85 Carrera long block. It had 71K miles on it when you installed it. I estimate it has about 90K miles on it now. It doesn’t leak any oil. Starts on the button hot or cold!

Here’s the original ad for the motor which was included in the paperwork file.

[Turbo_pro]

Originally Posted by 4CamGT

Henry, the main reason I changed it was I wanted a more hidden and discreet factory look. .....edit.....

This seems a little odd. Obviously the rear flairs are more detrimental to the "factory look" than a completely and easily removed deck lid.
As I understand Henry's conversion, there is zero modification to the original body and chassis. Zero modification if you source a different engine lid like stevesc_us apparently did.

[4CamGT]

Originally Posted by Turbo_pro

This seems a little odd. Obviously the rear flairs are more detrimental to the "factory look" than a completely and easily removed deck lid.
As I understand Henry's conversion, there is zero modification to the original body and chassis. Zero modification if you source a different engine lid like stevesc_us apparently did.

The rear flairs apparently have been on the car since it was almost new. There’s no evidence of them being added or welded on as the original undercoat is undisturbed. As I was curious about their origins, I went to visit the Porsche Museum some years ago. I was given personal access to the Piech 914-8. They graciously allowed me to take templates off of the rear flairs to compare with mine. They’re the same. Also of interest are the flairs on the 914-6GT prototype. Also similar. The most plausible scenario is they were modified in the early 70’s in the Bay Area where my 6 lived.

I have a set of NOS factory GT flairs and I have a pair of stock factory rear fenders. So far I like the look as it is and it allows the 8R rear Fuchs.

On the cooler install, they were installed without any cutting or holes added. We used existing bolts and studs by creating custom brackets.

[Turbo_pro]

I like the flairs and your car is beautiful. I saw it in Costa Mesa when the cooler was being installed. I did a similar flair on one of my 6s back in the late 70s so yes, flairs have been added to 914s for decades. I even like the add on passenger mirror.
It's your car and you can do whatever you want. It's just weird that you find a need to justify your decisions.

[4CamGT]

Originally Posted by Turbo_pro

I like the flairs and your car is beautiful. I saw it in Costa Mesa when the cooler was being installed. I did a similar flair on one of my 6s back in the late 70s so yes, flairs have been added to 914s for decades.
It's your car and you can do whatever you want. It's just weird that you find a need to justify your decisions.

Cooler was installed by Ed Palmer at KundenSport in Oxnard (now in Santa Paula). BTW, just sharing the journey. I did a lot of online searching for successful rear cooler solutions for the 914-6 with few results. I’m putting this here to hopefully help the next enthusiast.