Joined
·
699 Posts
So the BP4W swap, there's a fair bit of info here so I'll try keep it in some sort of order.
Just to recap, the head is a 1.8 BP4W from a mk2, it's been stripped down and skimmed 20thou, as well as getting the valves recut as they were too far gone for lapping.
IMG_20200527_202318_1 by Scott Reid, on Flickr
After machining I stripped it down and applied assembly lube as I wasn't sure when it'd be fitted:
IMG_20200605_191240 by Scott Reid, on Flickr
Bought a mk2.5 "flattop" inlet manifold, as the mk1 inlet would no longer fit, comparison with a mk2 inlet:
IMG_20200430_190250 by Scott Reid, on Flickr
As the mk1 doesn't have EGR, I fitted the Jass Performance blanking plates to the back of the manifold. You can also see the set of mk2 injectors, that were sent to Injectortune for cleaning and flow testing.
IMG_20200611_220321 by Scott Reid, on Flickr
All built up and ready to go on the car:
IMG_20200611_215719 by Scott Reid, on Flickr
Split the mk1 engine after running through some coolant and oil cleaners:
IMG_20200622_182414 by Scott Reid, on Flickr
IMG_20200626_183057 by Scott Reid, on Flickr
IMG_20200626_183207 by Scott Reid, on Flickr
Used the RevLimiter guide for cleaning the pistons, with some Mopar combustion chamber cleaner:
IMG_20200716_204705 by Scott Reid, on Flickr
IMG_20200721_201407 by Scott Reid, on Flickr
Had to invest in a Jass crank bolt removal tool, worked really well and certainly didn't struggle to get it cracked and off:
IMG_20200624_192146 by Scott Reid, on Flickr
IMG_20200623_194337 by Scott Reid, on Flickr
Other than that, it was relatively plain sailing, following the Car Passion Channel timing belt video replaced the: waterpump, front crank seal, cam seals, idler/tensioner pulleys, head gasket, exhaust/inlet gasket, coolant sensors at the back of the head, all engine hoses for red stoney racing items.
I also swapped the mk1 starter motor for a mk2 item from Autolink, they were on offer, just to note these only fit with 2 of the 3 bolts and you cannot utilise the mk1 L-shaped bracket either. Where the mk1 unit cranked 3 or 4 times before starting, the mk2 unit cranks 1 or 2. A worthwhile swap.
IMG_20200715_201207 by Scott Reid, on Flickr
I also swapped in a mk2 throttle body, so it's now got the revised IACV unit, that's much tidier. Slight modification to the throttle cable bracket (moving the cable to the top slot) but you can use a mk1 throttle cable and don't need a later (shorter) cable.
On a side note, cleaning your expansion tank? use dry rice, worked a treat.
IMG_20200730_191220 by Scott Reid, on Flickr
So with new plugs, oil and filters, the car started first time with a bit of help on the throttle. sorted the idle and the timing (14 degrees) ran up to temp and replaced the coolant. Have since been on a couple test drives and have noticed the following:
- Oil pressure is now slightly higher than on the original engine
- Coolant temps sit slightly lower.
- Definitely feels faster as well as smoother on the power.
- Certainly pops louder than it used to.
Plan would be to get it to the same dyno as before to compare the pre swap to post swap, I've also got a Speeduino ECU to fit at some stage, once I get a wide-band to fit along with it.
Anyway, that's quite a lot of information for now, I'll keep testing it until I'm happy to put the under-tray back on.
Thanks for reading.
Just to recap, the head is a 1.8 BP4W from a mk2, it's been stripped down and skimmed 20thou, as well as getting the valves recut as they were too far gone for lapping.

After machining I stripped it down and applied assembly lube as I wasn't sure when it'd be fitted:

Bought a mk2.5 "flattop" inlet manifold, as the mk1 inlet would no longer fit, comparison with a mk2 inlet:

As the mk1 doesn't have EGR, I fitted the Jass Performance blanking plates to the back of the manifold. You can also see the set of mk2 injectors, that were sent to Injectortune for cleaning and flow testing.

All built up and ready to go on the car:

Split the mk1 engine after running through some coolant and oil cleaners:



Used the RevLimiter guide for cleaning the pistons, with some Mopar combustion chamber cleaner:


Had to invest in a Jass crank bolt removal tool, worked really well and certainly didn't struggle to get it cracked and off:


Other than that, it was relatively plain sailing, following the Car Passion Channel timing belt video replaced the: waterpump, front crank seal, cam seals, idler/tensioner pulleys, head gasket, exhaust/inlet gasket, coolant sensors at the back of the head, all engine hoses for red stoney racing items.
I also swapped the mk1 starter motor for a mk2 item from Autolink, they were on offer, just to note these only fit with 2 of the 3 bolts and you cannot utilise the mk1 L-shaped bracket either. Where the mk1 unit cranked 3 or 4 times before starting, the mk2 unit cranks 1 or 2. A worthwhile swap.

I also swapped in a mk2 throttle body, so it's now got the revised IACV unit, that's much tidier. Slight modification to the throttle cable bracket (moving the cable to the top slot) but you can use a mk1 throttle cable and don't need a later (shorter) cable.
On a side note, cleaning your expansion tank? use dry rice, worked a treat.

So with new plugs, oil and filters, the car started first time with a bit of help on the throttle. sorted the idle and the timing (14 degrees) ran up to temp and replaced the coolant. Have since been on a couple test drives and have noticed the following:
- Oil pressure is now slightly higher than on the original engine
- Coolant temps sit slightly lower.
- Definitely feels faster as well as smoother on the power.
- Certainly pops louder than it used to.
Plan would be to get it to the same dyno as before to compare the pre swap to post swap, I've also got a Speeduino ECU to fit at some stage, once I get a wide-band to fit along with it.
Anyway, that's quite a lot of information for now, I'll keep testing it until I'm happy to put the under-tray back on.
Thanks for reading.