6 replies to this topic

[BaronVonchesto]

So my oil pump is almost knackered. Pressure is dropping to 10psi at idle when the oil is really hot. So i guess its time to take the engine out.

 

This will be my first attempt at a rebuild. I have a Haynes manual, a torque wrench and youtube videos to guide me. It's going to be an adventure!

 

As everything takes 3 weeks to get here from the UK I figured I'd order some of the essentials now even before I've taken out the engine. I'm trying to keep the cost down, but if I'm going to the hassle of taking out the engine to change the oil pump I might as well change the things most likely to wear out as well. What are the essentials that must be changed everytime the engine is opened up? I've already ordered the minispares engine rebuild gasket kit, so I figure I have all seals sorted. So it's on to parts now.

 

Here's what I have. Please fill in the gaps:

1) Main Bearing

2) Bigend bearing

3) Cam followers

4) Oil Pump

5) Water Pump

6) Unleaded vale seats

7) Valve guides

8) timing chain tensioner

9) central oil pickup

 

What else needs doing?

 

also if you could post links to minispares parts or the part numbers that would really help me in finding the right parts to order. This is a road use car, not exactly fast road, but I'd like it to perform better than it currently is (fully stock)

Edited by BaronVonchesto, 20 January 2019 - 05:41 PM.

[Mr Dave]

Sounds like a comprehensive starting list.

Before you get the bearings, check the crank journals - they may need a regrind if worn (or could even have been reground previously). Oversized bearings are available in 10 thou increments

If you’re swapping to a central oil pickup you’ll have to at least partially strip the gearbox, so depending on age/condition it may be worth a rebuild of that too.I am currently in the final stages of rebuilding mine and on top of the planned rebuild I also had to replace 2nd gear as the dog teeth were mashed.

In terms of performance, take a look at your cam - they can wear around peak lift which hurts engine breathing. May be a good opportunity to upgrade (there are several threads regarding cam choices on here)

[unburntfuelinthemorning]

What is the oil pressure at higher engine speeds when driving and when it's really hot?

[BaronVonchesto]

What is the oil pressure at higher engine speeds when driving and when it's really hot?

oil pressure is never higher than 50 psi, which itself is okay. the problem is more of low rev oil pressure.

 

though ive seen it dropping steadily the past 2 months. it used to be a steady 70psi at 3000 rpm, and now its down to about 49 or 50.

[BaronVonchesto]

Sounds like a comprehensive starting list.

Before you get the bearings, check the crank journals - they may need a regrind if worn (or could even have been reground previously). Oversized bearings are available in 10 thou increments

If you’re swapping to a central oil pickup you’ll have to at least partially strip the gearbox, so depending on age/condition it may be worth a rebuild of that too.I am currently in the final stages of rebuilding mine and on top of the planned rebuild I also had to replace 2nd gear as the dog teeth were mashed.

In terms of performance, take a look at your cam - they can wear around peak lift which hurts engine breathing. May be a good opportunity to upgrade (there are several threads regarding cam choices on here)

 

yea i'll definitely be partially stripping the gearbox to inspect the dog teeth and synchros. i dont want to go crazy and order parts without inspecting the engine components first, but i do want to order the must replace things in advance to save time.

 

im considering changing the timing chain to the minispares simplex EVO one. is it recommended to change the cam gears as well? i read that the evo chain doesnt require a tensioner

[Minigman]

I’d take a look at the cam whilst you have the engine apart. The Minispares evolution 001 is cheap and gets good reports in a 998, although I’ve not used one myself. That said the engine would benefit from an improved cylinder head to make use of the cam, but that can be done later if funds are tight at present.

As said above, once stripped down get the engine measured properly for wear on the bores and the crank. It may well need a re-bore to the next size up and the crank may need a grind too. That will determine your bearing sizes and piston requirement. I’d also do the cam bearings at the same time as it’s relatively inexpensive.

[unburntfuelinthemorning]

Cam gears will need inspecting.  I'd recommend  duplex kit with new gears anyway.  Tensioner not required although some people still fit them.  Might as well put a new clutch in.  Don't forget new locktabs.  If you're partially stripping the gearbox you'd be silly not to replace the bearings.