Race Engine Forum UK

H Mr. Croft and ohter dedicated specialists!
Have problems with wear on one off the lobes on my EX cam This has happend with 2 camchafts ,but not the same lobe but only on the EX side, Running in procedures for camchafts followed , The engine is standing straght up ,not angeled as they are intended to do in FWD cars. Fitted in my X 1/9.
All sort off things has been checked , Oil flow , Bleed out on the cam bearings, .Good oils , In Seme Syntectic ,. and fully synthetic.

After contackting my friends ,and wee have inspected the oil neveu on the oil boxes , we have the impression that the oil levell is to low in in the oil boxes on the EX side ,

We have found out that we have to rise the oil lewell in the boxes with obout 5 mm , by insert tubes in the oil return holes.
I have made som scetches on the original split plan off the engine in tilted posisson , And it looks to mee that the oil levell when tilted is higher . But whenn standing straight up beeing lover And scuffing off the lobes will oceur.

I kan see that one off your customers Mr, Croft is running a 16 V in a Morris Minor ( impressing car ). He must have some experience?

By the way Remme did gave mee your book nr,14 and it is impressive work and investigason , i read every day .Hope i can come thru in a year or so, thank you for impressing work.

Ove Thorkildsen Oslo Yes - 12 degrees minus outside today!

Hi Ove

I know English is not your native language but thank you for doing your best! Thanks for your kind comment about my new book!

I have not heard of a persistent wear problem with engine in original position or vertical with that head.

First please tell me:

1. Exactly what make the ex cams are which are wearing.
2. Are they steel, cast-iron
3. Are they ground from blanks or regrinds
4. Did you use new shims
5. What is the cam lift?
6. What valve springs are you using?
7. What is the fuel system (carbs/FI)?

A photograph of engine and car would add some interest..

G

Question Nr 1 They are OE Fiat Tipo cast.
2 Cast -iron
3 Not as I can see ,looks srandard.
4 Not on all , but on the bad lobe yes.
5 8,60 mm
6 OE Delta integrale 1991
7 OE fuel FI and five rounds on the track with throttle bodys and 430cc Boech injectors, dident work .

More Picks on your Web under My Fiat Abarth Prototipo Replica.

Reg OVE

Good answers thanks!

I am not sure about your cams - see photo. My guess is: the two cams on the left are either something like steel billet C&B (Columbo) or have been reprofiled and machined to make them look like billet cams.

It is possible (yes - I know you are very experienced..) that the running clearance is wrong. If the clearance is too loose you get rapid wear near full lift on the cam lobe and if too tight it wears on the base-circle and ramp. Regrinds invariably need much tighter running clearance than OE.

See also my note on the photo about the oil feed tube..

G

My engine had the same problem.

100% sure that the cams in my engine were OE and unmodified.

But for the rest I can not speak as the damage occured before I got it. And as can be seen from my thread previous owner didn't take care of the car really.

May have said this before but some causes of aggressive nose wear are:

1. Clearances too loose (follower never even 'sees' cam opening ramp and just skips straight to the nose)
2. Failure to bed-in cams with proper cam-lube at first start
3. Trailering the vehicle to events - this can drain all the oil out of the head so the engine starts 'bone-dry'. This is certainly a serious risk with the 8V TC units BTW...
4. Springs way too hard or actually coil binding ('boxing')
5. Oil degraded by way over-rich fuelling

...as I said - some of the causes....

G

Thank You Mr Croft for your info . I will try to chec all. Regards OVE

Hi again .Have now examined lub system off camchafts ,an i have discoverd the following!

1 My oil tube for lub off the ex camms was fitted the wrong way.
2 The first cam bearing near the cam pulley on the ex , camm was bleeding too mutch due off to to big play. That affected the flow to the rest off the bearings and lobes. That was easy to spot whenn the head was on the bench and the oil feed hole was presurized,
3 My opinion for engines who is fitted vetical have less oil around the buckets on the ex side than inclined engines.
4 I will now block the 2 oil return holes on the ex cam side in the head,in order to have the same levell as the intake side. This is just a test ,and i will see how it goes.
4 Also i have been checked all the good hints from Mr. Croft.
5 Now i think iam ready for new camms.

Sorry for my Englich, I havent even had english att scool.
Reg Ove

Thanks for posting your report again Ove,

don't worry about your English, I can understand your posts no problem, I know you do your best,

thanks for your kind comment on my youtube channel by the way...

G

torkil wrote:Hi again .Have now examined lub system off camchafts ,an i have discoverd the following!

1 My oil tube for lub off the ex camms was fitted the wrong way.
2 The first cam bearing near the cam pulley on the ex , camm was bleeding too mutch due off to to big play. That affected the flow to the rest off the bearings and lobes. That was easy to spot whenn the head was on the bench and the oil feed hole was presurized,
3 My opinion for engines who is fitted vetical have less oil around the buckets on the ex side than inclined engines.
4 I will now block the 2 oil return holes on the ex cam side in the head,in order to have the same levell as the intake side. This is just a test ,and i will see how it goes.
4 Also i have been checked all the good hints from Mr. Croft.
5 Now i think iam ready for new camms.

Sorry for my Englich, I havent even had english att scool.
Reg Ove

Thanks for letting me have a look at Your X1/9 project. Learned quite a few things at Your place. Some serious ingenuity performed on Your car, clever and simple solutions everywhere. Good luck with the 16V head - With Your mods lubrication problems are now hopefully sorted;-)

Best regards

Remi