69 road race Ghia rebuild

[curtw_944]

Ian they are a 52mm offset.
_________________
So Many Hobbies,
So little time!!

[cmaxcliff]

Hello Ian. I have been building 356 race engines for a long time but I am now starting a Type 1 race engine project for my Devin D vintage road race car. My concern is keeping reasonably cool oil temps for 1 hour of flat out wheel to wheel competition. VWs have a reputation for poor cooling that is confused by all the different heads and cooling systems available. 356s may have better cooling heads and those use no engine mounted cooler and a front mounted cooler for 1622cc and 165hp. What have you done to cool better? What heads did you have that ran hot? I will be curious to see how the JPM heads cool since they don't have much flow through cooling. Was heat why your cam failed? What cooling did you use then and what do you intend to use for the additional power? FWIW our rules limit me to 1717cc and my target is 200hp@8000rpm.

[Ian Godfrey]

Hi cmaxcliff, this is a bit long winded but a complex topic. The heads I used, (Street Eliminator), have poor thermal performance because of the 6 fin design so I did everything I could to the motor to improve cooling, breaking it down into, into optimising the oil cooling and the air cooling.
First up, I don’t think you can reliably track race 200Hp without Nicasil barrels (aluminium). Many Porsche engines (4 & 6 cylinder) and a lot of the road race type 4 engines all use this technology. Also critical I think was the HPC coating package:
Thermal barrier on combustion chamber, valve heads and piston tops, Moly Disulfide coating on piston skirts and valve springs. Non wettable coating inside valve covers and thermal dispersant on the outside of the valve covers and outside of the cylinder heads, ceramic exhaust coating, and lastly Calico coated bearings.
Drilling more air passages in the heads and adding the little tin deflectors https://www.awesomepowdercoat.com/cylinder-head-internal-deflectors
And cylinder tin air vanes
https://www.awesomepowdercoat.com/cylinder-tin-air-vanes
All tin ware including a venturi ring, factory thermostat and flaps, ‘industrial tins’ a deep sump (also coated inside and out) and ¾ side head oil drain to the sump. I ported the inside of the case to help get the oil down to the sump quickly. As well as a type 4 cooler in the shroud, I used a Mocal sandwich thermostat going to a small Setrab external oil cooler with a fan (FP119M22) with a thermo switch.

After all this the main problem that showed up was lack of air to the engine compartment, cos there was not enough air through the factory grill for the carbies and cooling. When I got up to 100Kph and put my foot down, the mixture went lean and the temps started rising. When I opened up the front of the boot lid an inch the heads went down 30deg C and and oil down 10deg C and I could run the car flat out for 4 laps of the track (20 Kilometers) without overheating and I got the mixture where I wanted it. Top speed was 180Kph (112mph)
In the end I think it was the metallurgy of the cam that caused the failure rather than oil temps. I ran about 5,000 K’s before the cam gave up.
I haven’t run the new engine with the JPM heads but I’m confident the temps will be fine even with more Hp as the cooling design is WAY better the old Street Eliminators. My backup plan is the bigger 2 fan Setrab oil cooler
I hope this helps and hasn’t bored everybody else to sleep