First timer, b27 to 25 full swap

[Supratreo]

Hi guys, my first post here as I am a noob to these cars. My only other experience with bmw is on my dad's e60 but I'm def. Not new to cars. I was a toyota tech for 10 years and love Toyota's before anything else.
I'm actually here to learn and help my cousin out with his newly aquired 87 325e, which I must admit is a lot of fun to drive.
I myself have a 93 toyota supra turbo which will be down after this car so I can do a v160 swap and full motor build.

Anyway, I've been doing a TON of reading because we are looking to do a 5sp and m20b25 swap.
We pulled a motor and harness (no ecu) out of a 89 325Ci last week and a trans from a local guy the week before but I have some questions that I haven't really been able to find answers to yet.
Before anything else, I want to go through the entire motor and replace all seals and gaskets because it's obvious this motor was leaking. What gasket kit would you recommend? Keep in mind I will also be changing the head gasket and installing ARPs for future boosting.

Also, as far as cooling systems it seems like I have 3 options:
1) stock setup with 2.7 WP and required hoses.
2) convert to 325I rad and expansion tank
3) m42 radiator
I think I have those right. What would you guys do? Now I was going to stick with option 1 to keep costs down but he might need a radiator anyway due to a leak but I will double check tomorrow.

I know these questions have been covered before but I can't seem to find anything that I can use to make up my mind.

Thank you for the help and look forward to bring a part of this community.

[Supratreo]

one more question, it seems like you can only get the gasket kits for top end or bottom end, is there any kit that covers it all?
from what ive found it seems like opinions on VR is 50/50 and of course people recommend OEM but that is about 4x more than VR. it would actually be cheaper to get a VR top end kit and just a OEM HG.
anyway, please let me know what you guys think.

thanks again

[digger]

id probably by a cheaper set and then only get the OEM HG

https://www.ecstuning.com/Search/SiteSearch/11111730875/

https://www.ecstuning.com/Search/SiteSearch/11129059240/

not seen an entire kit

[Supratreo]

thanks for the reply. ECS is where i have done all of my e60 shopping and they have been great. is there any other places you guys recommend i check out?

[ForcedFirebird]

Use the VR or Elring gasket kit and use a Goetze gasket itself at the minimum. I posted comparisons a long time ago, quality difference is enormous. The OEM BMW is the best, but we have ran Goetze on o-ring'd turbo, ITB, endurance engines etc and they are just as good as OEM IMO. They have a nice copper layer with thick double lined silicone. The VR, Felpro, and Ealring all have very thin single silicone lines and are known to leak outside the head bolts, just below the exhaust gaskets where the m20 has the oil drains.

Keep your cooling system your car came with if you simplicity. Nothing wrong with the early model setup, the 87 325is came that way. We have never had one system fail more easily than the other, but the early hoses are far less expensive since the late model has the large tee hose for the expansion tank, and the metal tube behind the water pump (price them out, even ebay sells them for $100+).

I prefer not to use the cork oil pan gasket, and use straight elastomeric (Hondabond, The Right Stuff etc). Again based on experience, the BMW oil pan gaskets don't last, all the way up to the new models. Glue that thing on there.

If you have grooves in the seal surface on the crank, cam, oil pump drive etc, pop the spring out of the seal, find the end and "unscrew" it. Cut 4-6 coils off the large side, reinstall. This will tighten the seal on the worn area, much better than using a ready-sleeve.

Refresh the head while it's off. Check the valve guides. Almost 100% of the heads we rebuild need at least exhaust guides. They are bronze so they are easy to replace. Most of these heads are tired and once freshened up, they really wake the engine up. Tired engines we see ~140-ish WHP, with fresh heads they pick up at least 15whp.

There's a lot more, but hopefully you have something to chew on for now. :)

Welcome to the "BMW small block" lol.

[Supratreo]

thank you very much for that in depth reply.

looks like i will go with the VR kit and OEM head gasket and toyota FIPG for the oil pan since i have a ton of it.

if i keep the original cooling system do i need to run a 2.7 WP on the 2.5? then just replace all of the old hoses with new?

thanks for the heads up on the seals.

i'm planning on at minimum, lapping the valves and replacing valve seals, checking main and rod bearings and obviously getting all the carbon out.
do you think its worth it to gasket match the intake and exhaust ports?

thanks again for the help

[ForcedFirebird]

Don't do any porting. We have done extensive flow testing at the shop and it's very easy to ruin the 885 head without flowbench data.

The 2.7/2.5 pumps are the same, they just have different sized pulleys, however, the pump has to match the cooling system since you will need an expansion outlet on the early cars/pumps.

Also, verify the wiring before plugging in the round connector on the firewall. There was a change to pin #20 and if it's wrong, you can fry things. BMW reversed that pin ground/power for airbag cars.

[Supratreo]

sounds good. so thats the ABS wire correct? i've read about that, just need to confirm what i have.

also, what do you mean the pump has to match the cooling system? i'm thinking i'd have to get whatever pump fits the cooling system in the car which is a 2.7 so that it would have a port for the expansion tank? just a little confused there.

[ForcedFirebird]

The coolant system is not "2.7" specific, it is year specific. The expansion tank is on the passenger side of early cars and the water pump has an outlet to go to it. On the late models, the expansion is on the driver side and fed via a tee that comes off the hose for the heater core. The pumps are identical for 2.7 and 2.5 besides that outlet.

[Supratreo]

Ok makes sense. So I have an 87 and the expansion tank is on the passenger side so I need an early model pump.
Isn't 87 when throngs started to change? If so do I just get a 86 pump to be sure?

[ForcedFirebird]

Go to realoem.com, enter in the last 7 digits of your vin and you will have access to all your car's part numbers.

[Supratreo]

thanks, i'll do that.

another quick question, what does the bottom end gasket usually come with? i'm thinking it might be cheaper if i just get bother crank seals separately since i wont be using the oil pan gasket anyway.