Hi Lads and Ladies,

Ive got a BF XR6 Turbo with a built FG engine in it. Cosworth pistons Atomic rods balanced crank etc etc..

When I built this motor billet oil pump gears, backing plate and ported oil pump housing with a stiffer pump spring where also installed. I realise a stiffer spring will increase oil pressure. Ive had this engine in about 2 years and it hasnt skipped a beat.. it runs very high oil pressure (80psi cold idle)  (20 psi hot idle) and 130 psi full noise 7000 rpm.

My question is can running excesivley high oil pressure blow out my rear main seal and cause leaks? The engine is fitted with a 10AN vented to atmosphere catch can. I cant see how it could in my mind thinking through the logistics of it but perhaps im missing something? If so is there something I can do or undertake to stop it happening? Like using "stag" or permatex aviation gasket to "glue" lock the main seal in?

(Sikaflex 227.. lol)

Looks like the engine will have to come out again 

(I say engine out again because it has a few minor dribbles around the pan that ill do at the same time)

to redo the rear main seal but I want to avoid this happening again in the future..

Thankyou in advance for suggestions

Brandon...

maybe @Puffwagon might be able to give you advice there as he's built high performance engines in his backyard  

 

seems more like a question for your engine builder or a generic engine builder, though?

Hi Keith,

I am the engine builder.. lol.. so no luck there..

I have built a lot of ford engines over the years

(worked at Dragon engineering) in my local town when I wad younger but I havnt ever run a modified oil system, I assume it wont be blow by as the engine never smokes and and has an adequate pcv system via the vented catch can. I was hoping I could work this out in my head before going balls deep and overlooking a possible soloution while I have it all apart. I will message Puff and see if he has an idea.. thanks for your time Mate.

Brandon.

Unfortunately he hasn't been on the forum for quite some time (since ~May 2025) so he might not respond to your PM. 

 

Still, calling around to some well-known-engine-builders (perhaps the people you bought your engine parts off), they be able to give you advice on that front. Make sure to come back here to tell us any advice you get

Hi Keith,

I got the majority of parts through Jet whom I havnt been able to contact of late so yeah ill try and sort it out.

Ill keep you updated as to what the outcome is, while im in there im thinking I might go back to a BA style sump with the one piece gasket adverse to the BF 2 piece half moons and RTV. Side note I should point out that Jet was nothing but extremely helpful and has nothing to do with any faults that im dealing with.

Cheers Brandon..