'Budget' DIY Engine Rebuild

silent running

OK well after looking at all the examples of how a port/polish job SHOULD be done, I picked up a Dremel for £4 from a boot sale and with a few small grinding stones, sanding rolls, abrasive buffs and brass brushes, I've got a much better finish, which tbh is as far as I want to go with it. Altogether, I've 'blunt-knife-edged' the inlet port divider and tidied the ports themselves up to a decent finish, polished the combustion chambers and taken any sharp edges out (mainly between the inlet/exhaust seats) and ported the exhaust ports. The inlet ports were fairly straightforward with a Dremel, but the exhaust ports were much harder because they are smaller and more twisty. But I did manage to grind out the casting blobs that were all over the bowl area around the exhaust valve guides. Next step will be to do the same to the other head then start assembling. TOP TIP: If you're DIY porting/polishing your own heads, forget using an electric drill. You need a mains electric (or air) die grinder/Dremel/rotary tool. This will be small and fast enough to do the job properly.

Overview of both chambers:



Polished combustion chamber looking down into the bowls under the valve seats:



Mildly knife-edged inlet ports, casting defects like steps, seams and bobbles eradicated. You can see where the inlet valve seats join into the port, it looks rough but it is smooth to the touch now, and I didn't want to take any more material out to blend it perfectly because that would alter the shape of the ports too much and from what I understand the valve throat needs to stay narrow:

scouse2

has the block been bored now?
what is the cost of your build upto
breakdown of cost would be nice ie pistons and rods
danny

silent running

Block is off for boring right now. Just waiting for it to come back. The 'balance of account' is pretty complex at the moment as I've been selling off unneeded bits as well as buying. Once the build's done and working I'll do the final reckoning but at the moment, pistons and rods have cost only £500 from CDF. I've kind of avoided putting prices up on here up to now, but a lot of people have been asking so there it is. You can't import them directly yourself from the States for much less than that, and then you have to take a chance on import duty, VAT etc.

nullfork

Great work / read mate. Doing a similair thing myself at the moment.

What you going to use for clearances when it comes to installing big end / main bearings; plastigauge or dial bore gauge / micrometer?

Also, what's your current status ?

silent running

I'm just using a digital vernier calipers to measure everything up. As long as all the dimensions are right, I'm just going to put it together and basically cross my fingers! The block has just come back from boring today, so I now have a pair of ported and polished v4 heads ready for STi3/4 valvetrain, and a block with bearings, crank, rods and pistons ready to be assembled. ARP head studs and hard anodised front pulleys are on the way from CDF. I'll be getting a new modine oil cooler and some Millers running in oil from AS Performance next month.

So now I am at the moment I have been both looking forward to and dreading at the same time, having never assembled an engine before...there's no way I can do any other little jobs, I have to get right on and start building everything up. Any tips from anyone about how to proceed with building up the short block? Or the heads? I have assembly lube, engine oil and Threebond 1215 at the ready. Where they all go though...?

ticky

I used the procedure below for assembling the heads to the short block using standard (re-used) head bolts.

Tightening sequence of bolts:-


.................exhaust side...................
.....................3 1 6..........................
front of engine......... Rear of engine ....
.....................5 2 4..........................
..................inlet side........................


Then tighten torque and angle in the following stages, in the sequence above

1. 29 N/M OR 22 FT/LB
2. 69 N/M OR 51 FT/LB
3. BACK OFF 180 DEG. (REVERSE SEQ 6-1)
4. BACK OFF FURTHER 180 DEG (REVERSE SQ. 6-1
5. RE TORQUE 29 N/M OR 22 FT/LB (1-6)
6. 80 TO 90 DEG. (NOT OVER 90)
7. 40 TO 45 DEG. (NOT OVER 45)
8. NO.1 AND NO.2 40 TO 50 DEG. FURTHER (NOT OVER 50)

Step 1-2 are basically for settling the gasket, as step 3-4 pretty much take all the torque off. Put a little bit of oil (or better still a small blob of moly grease) on each bolt thread.

Don’t guess the angles. Get an angle disc for your torque wrench.

I managed to buy a cheap angle gauge from a local motor factor shop for 4.99, the same gauge was going for about 10 gbp on ebay. I will try to post a link of the same gauge.

I would check the crankshaft/bearing clearances using plastigauge. At least you will have peace of mind that the clearances are to spec as you have re-used the original crank.

Ticky

ticky

Here's the angle gauge

Torque Angle Gauge - 20699A

silent running

Cheers for that. I have an angle gauge already, but where do you get plastigauge from and how does it work? From what I've seen you lay it in the clearance you want to measure, tighten everything down and work out the gap from the scuffing?

ticky

You've got it right. The plastigauge looks like a strip of plasticine, once its squashed you measure it with the paper thickness gauge which is provided with the kit.

You can get it from ebay or Plastigauge *(M630) - Frost Auto Restoration Techniques

I would just double check the measurement range before buying.

Ticky

Matt578

Your pulling ahead of me here nick, hopefully my blick is going off for boring end of next week you are going to be the guinni pig lol

silent running

So let me just check that I've got this right... I'll actually trial fit the main and big end bearings and basically assemble the crank and rods but with plastigauge stuff in the clearance spaces?

I can see how you'd measure the big end clearances, presumably just tighten the caps down then open them up again to look at the plastigauge stuff. But how would I do the mains? Actually bolt the two block halves together with the bearings and crank in place?

Two other questions for the engine builders on here:

1. Do I use assembly lube everywhere the manual normally would recommend you use engine oil to assemble? And one side of the bearings is put in dry?

2. The manual shows to assemble the crank/rods and fit them inside the block halves then bolt the crankcase together, then attach the four pistons afterwards. Is there any reason why I couldn't attach two pistons to their rods first of all, then fit them into the bores with the big ends dangling through the bottom, then attach the crank, then put the block halves together, so I'd only have to mess about with piston pin access holes on one half of the block?

silent running

Maybe, but I've still got to lap in a set of valves, assemble the heads, and get the valve clearances all proper with the shims I've got.

Tim W

Yes, easiest way is to attach the pulley wheel to the crank and use it to hold the crank in a vice.


Yes, but you only need the crank, bearings and block halves assembled


On the rotating parts, not the piston rings, just use oil there.

Assemble one half, coat the crank bearing surfaces and lower it into place and then offer the other block half up making sure that all the block mating surfaces are dry and oil/lube free. Also use the assembly lube when fitting the cams.


No reason at all, that's how most builders do it.

catalunya 172

thought you might be intrested in this link fella hope it helps with your build its a 2.5 build but im sure its the same for 2 liter and have you had any progress on the build?? here is the link Subie TV

silent running

Yes I've made some more progress, slowly! I've now managed to get the plugs out for the oil and water galleries in the heads and cleaned them out thoroughly, first with carb cleaner, then a hosepipe then WD40 into the oilways and the rocker side of the heads to keep them from going that funny colour that aluminium does if you leave it wet.

I've now got one of the block halves on the bench to drill out a crankcase bolt that had sheared off inside. It's slow going but I think I'll get it out in the end. Luckily it was one of the 'backbone' bolts so easy to get at.

Once that's out, I'll be degreasing the block halves just to make sure there's no honing oil with swarf in it lying around, and basically blasting the thing clean. Then I'll re-oil the bores to keep them rust-free and start trial fitting the crank and main bearing shells into the block with plastigauge to check the clearance. Then the crank will come out and the rods and big end shells will go on, again with plastigauge to check the big end clearance. If all checks out, then I will start assembling the block halves together with all new seals.

Simultaneously I am tinkering with putting the STi valvetrain into the heads.

catalunya 172

will look farward to seeing how you get on fella