Turbo 325

[2mAn]

those are some great numbers, Ive been trying to convince my buddy to follow through on turboing his m20

[bangn]

Getting closer to being able to provide a dyno sheet but here is where we're at

Previous engine made 350rwhp at 22 odd psi, its now making that at 14psi

Tuner got to 416hp @ 20psi today until it started blowing cooler hoses, the clamps have found their limit so hes going to swap
out the clamps Monday so he can finish off the tune.

He advised the new AMC head is WAY better than the 885 head and that its spooling up the turbo a lot sooner, gains across the board there so i'm stoked with that.

Advised fuel pressure is becoming an issue with the compensation for boost, the pump is plenty big but its sounding like the connector/power feed to the pump is now insufficient

We are now pushing the limit for 98 fuel as timing is now requiring to be pulled at higher boost pressure to compensate. E85 and a larger gate will likely be required on the next loom build.

7k RPM is the limit with this intake its seeming but I expected that.

Mechanically the engine is doing very well and has a lot of power left in it. However now all the power is essentially on tap instead of having to work for it, it may be enough? time will tell.

I have requested a video of the run so il be sure to upload when I have it

[bangn]

been a bit so thought id update.

Car is driving again and has been going for a couple of months without fault. Trying not to jinx it however I am very happy so far. I've completed 320kms (200miles) with the reduced power run-in tune and all the vitals are really consistent. I performed a check over the valve train couple days ago and only really found a handful of adjusters to be out .05mm. The AMC head I unfortunately was not able to get cnc matched as the business I was going to use seems to have shut down. TBH I am kind of glad that I didn't because I learnt that not all ports are parallel on the AMC head and I feel there would probably be enough core shift there to break through a wall.

So I took a different approach. I spent nearly 40 hours on the port cleanup myself and spent probably longer researching port designs. The design is very close to how my last head ports were however I feel this head promotes intake velocity more due to a narrowing just before the valve stem. The 885 head is a fairly straight port to the valve seat however the AMC funnels. The inserts also sit much lower in this head. The throats didn't even need to be touched as they were exactly the same size as my last head AFTER the valve job. The headshop that tried to repair my last head didn't even charge me to put in the larger valves and multiangle seat job. Absolute legend he was!

I've also noticed with the AMC head that the intake is MUCH cooler, the 885 head seems to use the intake almost like a heatsink and was always hot after a drive. Now its as cool as a cucumber after an hour and a half of driving.

the 2.9 is a very different M20 to drive, there is loads of torque and you forget it even has a turbo its that responsive, essentially no turbo lag. I am able to overtake cars in 5th gear at 100kmhr without even having to pull back a gear to get the motor going. Torque is just everywhere and its still fast doing a 3rd gear pull with a lowered rev limit. Then there is the sound, its much different. Far more angry on gate.

Hopefully by the end of July we should see the proper figures after the final tune but I think its going make me shit myself

[Panici]

I imagine the reduced flow won't matter as much in a forced induction application.

Of course an engine that flows better (and makes more power) N/A will also flow better when boosted, but when you can dynamically adjust the amount of air via boost pressure it isn't a big deal.


I've read that new engines are being designed more for knock resistance than flow (shallower valve angles among other things?).

The idea being that you can just cram more boost in there on a knock-resistant engine to make the same power, and run a lower octane fuel in the process.

[zwill23]

Man that's a tough break.

I keep hearing more and more stories of the 885 heads cracking, seems at this point it's luck of the draw when having one built. Going with a new AMC head is a smart decision I say, I imagine the reduced flow won't matter as much in a forced induction application.

[bangn]

so small update, 2024 is proving to be quite a challenging year. So on top of the cut-ring gasket failure I've experienced on this engine, its also been found the head had developed a crack in it from said gasket and was not picked up by my machine shops usual testing before I bolted it down the second time round. It was cold pressure checked but probably should of been hot pressure checked its been found as it had a crack an inch long inline with the head bolt supports on the intake side on cylinder 5. The shop wanted a challenge and offered to fix it for me for free, however once they heated it up it cracked from head bolt to head bolt. I've never seen something so cavernous. Worth a shot I guess if I could of obtained another year of use from it whilst I source a replacement but that's life for you. Downside is that its taken two months get the answer I needed from the shop but nothing seems to happen fast in the machining world anymore.

So I've ordered a new AMC head, well aware the ports suck but there is a machinist in Adelaide called Knight engines who I've believe have the ability to get them to flow a bit over 200cfm so hopefully I can see that through. Hopefully can get on top of this car in the next couple months.

Other news the other E30 I have which is a 323 ive picked up a VCT SR20 combo for it, but really bad timing with this head. I want to start but I refuse to start until this car is back together.

[bangn]

40 degree days have backed off a bit so had a chance to do this today. Took 6 hours which included masking everything up, vacuming as I went to prevent galling and marking the bores. Got the protrusion and spacing bang on which I'm very happy with seeing it was my first go at oringing a block. Def not a quick job in situ. Best thing is the oring grooves fell exactly where the marks were in the block left from the back of the cutring so that worked out well.

Hopefully does a better job at sealing than the cut ring gasket that shat itself after an hours use.

[bangn]

The quality of improved racings products are exceptional, highly recommended!

[bangn]

So car is getting a run in and tune on the dyno in a couple of weeks. Will only be on gate pressure whilst its got running in oil in it. Once ive put some road hours to break the engine in a bit further I will take it back for a power tune I would say Early Feb.

Sync issue so far seems to be resolved with the tone wheel reposition so fingers crossed it stays that way, hard to confirm much when I cant run it for a long period.

Ive decided to re-do the oil filter relocation setup as I would like to incorporate an engine oil cooler. I found with the current setup the exhaust manifold is pretty close to the in/out fittings on the Derale relocation block and feel I am taking on some excess engine oil temps due to this. The Derale block is chunky and then with an added NPT fitting plus 90 degree fitting it makes the stack height excessive. So may as well do what I can now to add some more engine protection. I'm sure on a power run the EOC will be beneficial to the tuner in maintaining good oil pressure. NPT fittings to me also just look yuck with excess thread hanging out.


So getting rid of the Derale gear and going with improved racing, must say I was really impressed with their website and ability to customize their products to your application, they run ORB fittings which is great and should help free up some room

Oil filter housing with thermostat. I have picked the 215f version as the vehicle is a street car.


Inline block so I can relocate the oil pressure sensor as well as incorporate an oil temp sensor


KOYO 19 row cooler, the SETRAB cooler nearly won selection but KOYO run ORB fittings so no brainer there.

[bangn]

Started today, its been a busy week. Cam is broken in and first oil change out was very clean exception to the slight shimmer under light, no nasty chunks in the filter. Its very peppy and surprisingly quiet on the valvetrain front. I thought the steel rockers would of been louder but its the quietest its ever been. Very smooth too.

Only issue I have is home sensor not staying in full sync and began to drop out after about 10 minutes, so Il need to reposition the cam tone wheel as its too close to the crank sensor event.

[bangn]

Finally got this thing off the engine stand. Spent a bit of time weighing the valvetrain to equalize the weights in the top end, Its pretty surprising when you buy new parts how much their weights can vary. Graph below is the final weight of each assembled valve assembly. Pretty sure its going to be smooth in that top end now. Scary to think if this wasn't done its possible to get a valve assembly to weigh 266 grams instead of 263.

INTAKE	Valve	Spring Outer	Spring Inner	Top Retainer	R/arm with adj	Total - g
1	72.17	42.88	17.76	15.55	115.64	264
2	72.6	43.73	17.37	15.26	113.45	262.41
3	72.44	42.98	17.74	15.53	114.61	263.3
4	72.2	43.3	17.56	15.34	115.59	263.99
5	72.43	43.44	17.38	15.29	115.49	264.03
6	72.47	43.17	17.6	15.5	114.27	263.01
EXHAUST	Valve	Spring Outer	Spring Inner	Top Retainer	R/arm with adj	Total - g
1	70.77	43.19	17.55	15.5	116.29	263.3
2	70.58	43.16	17.67	15.43	116.41	263.25
3	70.78	42.83	17.94	15.5	116.15	263.2
4	71	43.16	17.7	15.4	116.07	263.33
5	71.49	43.08	17.73	15.41	116	263.71
6	71.53	42.84	17.81	15.58	115.96	263.71

[bangn]

So received the head back and for once things went pretty well with the headshop I picked, never used them before so was a bit of a gamble like always. light face performed, multiangle seat job for the +1mm I&E, guides were pretty worn so k liners were used.

However I did hit a snag once I got home lol, I started weighing all the valve train components to start balancing out the top, I got to 8 valve springs and found the company I used for the Schrick products accidently short shipped me.
so I reached out a few weeks of delivery and they rectified the issue without a fuss and shipped out the missing ones with DHL. So I should have in a couple of days. BAR-TEK are great and I wouldn't hesitate using them again. Mistakes happen.

so in the meantime I did PTV clearance, found I have a fair bit more than I thought id have with the 1mm oversize valves, I didn't stuff with the ports too much as they're not the easiest things to improve without a lot of R&D, a flow bench and CNC machine
So all I've done is delicately taken out casting lines/steps to aid velocity.

[bangn]

Its funny you should say that Varg, I said the same thing after I picked up the block to a friend of mine. The hobby is enjoyable until I ever have to outsource work, it seems to have gotten worse in the last five years. Companies are just not interested in delivering things in a reasonable time frame, do not communicate effectively (had a few ghosters) and seem to be either way too busy and/or lost their passion due to dealing with the ever increasing customer expectations. I have an M52 disassembled ready for a rebuild for another e30 and to be honest given the experience i've had I am tempted to just bottle brush it and do everything at home exception to facing the head. Things go fine when I have control.

The 24v head I had skimmed and hot tanked came back with valves hung open because of crud on the seats. Glad I inspected closely.
That's a pretty easy job in terms of machine shop work. I'd hate to see what they'd do to a bottom end.

yep this is the exact issue, I swear they test the water and see what they can get away with in terms of doing the absolute minimum hoping the customer is uneducated enough to notice

[varg]

Ouch, sorry to see. It is going to be a seriously cool engine though once it's together and making power. Not numbering anything is stupid, how hard is it to get a paint pen out and mark stuff? Seems a lot of people have been complaining about their local shops going downhill lately. The frustrations I've had with bad parts over the past few years has me wondering if this hobby is going to be more frustration than enjoyment for me in the future, was it always like this? I don't know. I couldn't afford to do fresh builds with new parts until the last few years and junkyard parts always just worked for me my whole life

[Panici]

Seems like it's becoming impossible to find a machine shop that does good work.

The 24v head I had skimmed and hot tanked came back with valves hung open because of crud on the seats. Glad I inspected closely.
That's a pretty easy job in terms of machine shop work. I'd hate to see what they'd do to a bottom end.