She rides

[427james]

Just to say a big thank you to everyone who assisted me (and commiserated) following the crank snapping on my 4.2 and taking the rest of the internals out.

After a month, it went out for its inaugural test drive as a 4.5 yesterday.

Once again, cheers to everyone for the support.

James.

[cossiemetro]

how does she feel ????

[427james]

Bit slower than before, I think it needs a bit of playing with to get it right. You can put your foot down half way now before the wheels spin!

Will report back when I have done a few more miles with it.

James.

[Touching Cloth]

Yep, sounds like a 4.5

[Ballsy]

did you do a straight swap for the 4.2 to the the 4.5 or was it just the bottom end you changed??

Just wondering cause iam in the same situation

[427james]

What, does it just need tuning or are they just slower due to the extra weight in the crank?

James.

[427james]

Yes, swapped the crank for a late 4.2 with larger counterweights, bored it out, dropped in new pistons and rods and liners and welded the sump where it had cracked.

Good as new and cost me £2000 in parts and reboring. Not as quick as before though, which is a slight concern.

[betty_swallocks]

Run it in

[427james]

I am running it in!

Its not as quick below 3000 rpm! I am not likely to thrash it now!

[betty_swallocks]

half throttle seems a bit much for running in

[427james]

You may be right.

Its been running several times and done a few short trips. It wont get thrashed.

[betty_swallocks]

Hope everything goes well for you

[427james]

Thanks. Out of interest, what do people think in relation to running in?

I was going to run it in for 500 miles and change the oil + filter. Too long/ too short?

[Extra 300 Driver]

I had a complete rebuild on my 4.2, new pistons, block, crank and cams. This is what I did;

Below 2500rpm for the first 100 miles, but occasionally ran it to 4000rpm to ensure good oil flow, but I only did this a couple of times.

100-500 miles up to 3500rpm going to 5000rpm as above, also changed the filter only.

500-1000 miles normal driving really, not going too mad!

Over 1000miles, floor it

[longbow]

I am doing this now. First 800 miles was on special running in oil (SAE30) to get the rings to bite, am now around the same on GTX mineral, again to ensure the rings are perfectly run in, and then will swap to Mobil supersyn 15w50 after Xmas. If you've got new rings I do hope you havent't filled with synthetic straight away as you will glaze the bores!!!

[Extra 300 Driver]

longbow said:

I am doing this now. First 800 miles was on special running in oil (SAE30) to get the rings to bite, am now around the same on GTX mineral, again to ensure the rings are perfectly run in, and then will swap to Mobil supersyn 15w50 after Xmas. If you've got new rings I do hope you havent't filled with synthetic straight away as you will glaze the bores!!!

Yes, this is very important. Its not so bad with new engines, as in BMWs or Merc, but trational engines like the AJP requires this bedding in process.

I made this mistake with the A series engine I rebuilt.

[ridds]

Extra 300 Driver said:

longbow said:

I am doing this now. First 800 miles was on special running in oil (SAE30) to get the rings to bite, am now around the same on GTX mineral, again to ensure the rings are perfectly run in, and then will swap to Mobil supersyn 15w50 after Xmas. If you've got new rings I do hope you havent't filled with synthetic straight away as you will glaze the bores!!!

Yes, this is very important. Its not so bad with new engines, as in BMWs or Merc, but trational engines like the AJP requires this bedding in process.

I made this mistake with the A series engine I rebuilt.

I concour. Very important. Also don't be afraid of the loud pedal, 1000 miles of light load will do the rings no good eiter.

[HarryW]

ridds said:

Extra 300 Driver said:

longbow said:

I am doing this now. First 800 miles was on special running in oil (SAE30) to get the rings to bite, am now around the same on GTX mineral, again to ensure the rings are perfectly run in, and then will swap to Mobil supersyn 15w50 after Xmas. If you've got new rings I do hope you havent't filled with synthetic straight away as you will glaze the bores!!!

Yes, this is very important. Its not so bad with new engines, as in BMWs or Merc, but trational engines like the AJP requires this bedding in process.

I made this mistake with the A series engine I rebuilt.

I concour. Very important. Also don't be afraid of the loud pedal, 1000 miles of light load will do the rings no good eiter.

Always understood high gear, low revs, high loads, does a lot more damage to a running in engine than high revs tbh.
I'm getting mine run in on the bench dyno (as I did when I got he RV8 rebuilt for he S too ) so don't have that to worry about it, I think ......just need the car now

[Extra 300 Driver]

HarryW said:

ridds said:

Extra 300 Driver said:

longbow said:

I am doing this now. First 800 miles was on special running in oil (SAE30) to get the rings to bite, am now around the same on GTX mineral, again to ensure the rings are perfectly run in, and then will swap to Mobil supersyn 15w50 after Xmas. If you've got new rings I do hope you havent't filled with synthetic straight away as you will glaze the bores!!!

Yes, this is very important. Its not so bad with new engines, as in BMWs or Merc, but trational engines like the AJP requires this bedding in process.

I made this mistake with the A series engine I rebuilt.

I concour. Very important. Also don't be afraid of the loud pedal, 1000 miles of light load will do the rings no good eiter.

Always understood high gear, low revs, high loads, does a lot more damage to a running in engine than high revs tbh.
I'm getting mine run in on the bench dyno (as I did when I got he RV8 rebuilt for he S too ) so don't have that to worry about it, I think ......just need the car now

You should never let the engine labor in any gear. Just watch the RPM.

Its a careful mix of RPM and load. Dont trat the engine with kid gloves, but also dont thrash the bollocka off it.

[cossiemetro]

good point about the oil most people don't know that my cossie is running in on a good quality mineral oil otherwise as above it will not bed in properly as fully synth is that good it can't wear