Fiesta ST Forums banner
1 - 5 of 5 Posts

·
Registered
Joined
·
21 Posts
Discussion Starter · #1 ·
Hi all, took my inlet manifold off today to fit itb's and noticed that the intake ports and the runners on the manifold are coated in an oily substance that has a fuely smell to it. just wanting to know if this is normal or if there is somethng wrong with my car. i had the engine rebuilt a year ago or so with new seals and everything (valve seals, piston rings etc.). ive got an oil catch can fitted to my car thats connected to the rocker cover breather and the crank case breather. ive also gutted the pcv valve and my catch can barely gets anything in it apart from a little bit of water over time. Any help is appreciated. Cheers.
Gas Automotive exterior Auto part Motor vehicle Engineering
Hood Automotive lighting Bumper Motor vehicle Sunglasses
Head Eye Human body Jaw Iris
 

·
Premium Member
Joined
·
245 Posts
What does the inlet look like on the tb end. Do the internal trumpets have crud all over them?

If its noticibly worse from the intake port side then it's 1 of two things, 1 valve stem seals have died an awful death (not likely if they were changed when engine was rebuilt). 2, its assembly lube and residual oil squirted into cylinders to run a wet compression test when 1st built (assuming the ff inlet was used from the get go on the rebuilt engine). Mine did this, but no where near as bad when I was running my forged engine in on the ff inlet, but I only covered about 250 miles, so the oil was still clean and hadn't been dirtied by air.
 

·
Premium Member
Joined
·
245 Posts
Or worse case scenario, whoever rebuilt it mixed the intake valves up and didn't lap them in (judging by the clean stripe on the bridge of the inlet port). It's hard to diagnose either without a compression test. It could be residual oil that's dirtied over time from carbon in the air, or it could be carbon from where your intake valves don't have a perfect seating, it could even be that your timing is slightly out and your intake valves have too much overlap, but you'd be down on power in that case.
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #4 ·
hi mate, thanks for replying, the throttle body end of the manifold is shiny clean, not a speck of oil or anything that i can see anyways, it appears to only be in the runners and ports of the engine. i wouldnt think it to be the valve stem seals as the car doesnt blow any smoke out the back and like you said they were replaced not too long ago although they were cheap seals so who knows. the engine was not professionally rebuilt, most of the rebuild was done by me and my dad (who knows alot about engines) but the cylinder head was professionally worked on (he put new valve seals and springs etc in it) by someone my dad knew who used to build formula 1 engines for a living and he said the cylinder head was in good shape when we got it back. the reason we sent the cylinder head to him to begin with was that the valves had made tiny groves in the pistons on the old motor due to the old valve springs being completely worn out and we wanted to make sure it was still good to use which he confirmed it was. we did not do a wet compression test on the engine, looking back i dont think we did one at all until much later after the rebuild but the car ran solid so i guess we didnt see the point. I doubt the guy who did my cylinder head mixed up the intake valves, its not impossible but hes been building engines for decades so i doubt he'd make a mistake like that. as to the last few things you mentioned, i wouldnt have a clue, the car has run mint for the most part, it made 152hp at the wheels stock internals, ff inlet, phase 3 cams, full exhaust among other things and was faster than its ever been afterwards. if its worth anything, the last compression test i did (several months after rebuild) with just a normal gauge, the numbers were (from left to right) 178psi, 172psi, 178psi, 180psi. ive seen other people run much higher numbers when theyve done theirs but i was told due to the big cams ive got that the number would be lower than usual. cheers.
 

·
Premium Member
Joined
·
245 Posts
hi mate, thanks for replying, the throttle body end of the manifold is shiny clean, not a speck of oil or anything that i can see anyways, it appears to only be in the runners and ports of the engine. i wouldnt think it to be the valve stem seals as the car doesnt blow any smoke out the back and like you said they were replaced not too long ago although they were cheap seals so who knows. the engine was not professionally rebuilt, most of the rebuild was done by me and my dad (who knows alot about engines) but the cylinder head was professionally worked on (he put new valve seals and springs etc in it) by someone my dad knew who used to build formula 1 engines for a living and he said the cylinder head was in good shape when we got it back. the reason we sent the cylinder head to him to begin with was that the valves had made tiny groves in the pistons on the old motor due to the old valve springs being completely worn out and we wanted to make sure it was still good to use which he confirmed it was. we did not do a wet compression test on the engine, looking back i dont think we did one at all until much later after the rebuild but the car ran solid so i guess we didnt see the point. I doubt the guy who did my cylinder head mixed up the intake valves, its not impossible but hes been building engines for decades so i doubt he'd make a mistake like that. as to the last few things you mentioned, i wouldnt have a clue, the car has run mint for the most part, it made 152hp at the wheels stock internals, ff inlet, phase 3 cams, full exhaust among other things and was faster than its ever been afterwards. if its worth anything, the last compression test i did (several months after rebuild) with just a normal gauge, the numbers were (from left to right) 178psi, 172psi, 178psi, 180psi. ive seen other people run much higher numbers when theyve done theirs but i was told due to the big cams ive got that the number would be lower than usual. cheers.
The numbers themselves aren't hugely important as gauges differ massively. As long as they're all close together which they are then it's all good.
 
1 - 5 of 5 Posts
Top