M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Swaps, Turbos, Buildups => Topic started by: benz-tech on November 14, 2013, 11:03:33 PM
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I have acquired an entire M44 including ECU EWS, key, Gt250 trans etc for install into my 91 318i. Not one to leave well enough alone, I am building the M44 w/ US S50 pistons to achieve approx. 11:1 compression and 1950 or so CC's.
I need a bit of help calculating compression ratio before I mill the pistons to fit.
I have 4 US S50 pistons awaiting the end mill to remove excess material off the deck. the numbers are below and I could use some help in figuring out the CR.
bore: 86mm
stroke: 83.5mm
HG thickness crushed and verified 1.6mm
dish of piston is 64mm X .8mm depth matching the .15 + deck of the stock M44 piston. (after removing approx. 2.5mm of the squish area of the piston)
I don't know the exact combustion chamber volume and the head is at the shop so I cant verify ATM.
Anyone better at math than I? or send me to a site with
edit: list of mods for frankenmotor.
M44 block, rods, crank, harness, dme, ews2, chip, cam sprockets, maf, coolant temp sensor, upper front timing cover, front cover and all timing components, beehive valve springs and retainers. All accessories inclu a/c and p/s
M42 late cylinder head, 6mm valves, mild port work.
E30 M42 oil pans, intake manifolds and valve cover, Temp sensor for guage, Cams with reground intake
S50pistons US (with approx 2.4mm milled off the deck- not a verified number),
S52 33mm lifters and trays.
M20 lwf -12.5lbs (still too heavy) and clutch
There you have it- arguably 6 different engines in one,
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So please verify my math - assuming a 35cc combustion chamber
485 cylinder volume
9.2 volume of HG
33. Chamber
527cc. total
volume at TDC 42 total –assuming a perfect flat top, 12.4:1
BUT
dish of the piston is 64mm x 59mmX 1.1mm
Dish: 4.0
531 / 46 =
approx. 11.5:1 static compression ratio.
I need to add 1cc to get down to around 11.3
Edited to reflect updated numbers.
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A bit of an update: The M44 head was cracked and needed every exhaust valve and every guide due to the poor cam/rocker design. So I found a late M42 head, and, using the M44 front upper timing cover, sensor and the M44 cam gears, it looks like I can run the M42 head. The S50 pistons have been milled to the proper deck height and are on their way with the block to get bored. Found a M20 flywheel and got it down to 17lbs before the belt on my buddy's lathe started slip. With the lighter M44 crank, pistons and rods I might just leave it there and not go any lighter, but I am tempted to.
I'll get pics up when I have something worth showing.
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Sounds like an interesting build, excited to see how it turns out!
How much did you end up milling off the piston tops?
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Wish I could help - this sounds like a very unorthodox, cheap & clever build. Using an M44 crank is a LOT cheaper than finding & machining the M47 crank.
I'm still trying to figure out how you gained 100cc's with new pistons, but I'm geometrically challenged. Keep us updated!
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If I build another 4cyl I will probably go with the M44 crank just because its more torque and MUCH more cost effective. Heck, an M44 crank is probably even easier to come by and cheaper than an M42 crank!
M47 is the way to go, but Im a cheapo so I just use whats available :)
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I started on the intake ports.
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Wish I could help - this sounds like a very unorthodox, cheap & clever build. Using an M44 crank is a LOT cheaper than finding & machining the M47 crank.
I'm still trying to figure out how you gained 100cc's with new pistons, but I'm geometrically challenged. Keep us updated!
Well 100 ish more CC's. 1940 cc total. I mostly picked the m44 bottom end to be able to use the S50's and get 11+ to one. C/R.
I could use some help picking cams. I'm hoping to find cheap re grinds. It will need to pass Cali smog when it's all said and done so im thinking no bigger than 270 at the most. Not sure of the int/exh split either. When I look at our benz heads, the intake valves are around 5mm larger and the exh valves are around 2mm smaller. I have a feeling BMW didn't get the ratio right. Cams could offset that a bit?
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Sounds like an interesting build, excited to see how it turns out!
How much did you end up milling off the piston tops?
About 2.4mm. They are still very much dish shaped. Now that I figured out how to post a pick straight from my phone, many more will come.
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For reference, I am running 272° / 258° cams with 11.4mm / 11.1mm lift on my intake and exhaust, respectively. Valve heads are the stock diameters. Static CR is ~11.5:1 and am using 24# injectors. No issues passing SMOG in the CA Bay Area where regulations are tight. As long as you have a GOOD software tune you should be just fine. That, and a functional cat.
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Thanks bmwman. My budget might force just an intake cam but I'd like something like your setup. MM seems to use a 10+ degree difference on their cam grinds, and I'd guess that they have spent some dyno time figuring that out. any issues with 91 crap gas and that compression ratio? Cams obviously help keep the DCR down and subsequently the combustion temps. At least at lower RPM's.
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So far so good on the garbage 91 octane winter blend stuff here.
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I'm only running 250*/250* combo with 10.4mm lift. Passed NJ inspection with no problem.
benz-tech...Be careful on your cam choice and don't go too big. From the pic of your port, it's pretty hogged out and that alone will drop your low end umpf. Adding an aggressive cam to that will make low end torque really suffer. Have you put the valves back in the head? I would double check to make sure they slide easily. Hard to tell from the pic but since removing all of the valve guide in the port I would check it.
So we all need to get some dyno time in so we can tell what all these mods actually do for us in the real world instead of guessing:-)
Mine is still road tuning and then I'll be ready for the dyno and be happy to share build info as well as tuning info.
Good luck with the build, it looks very promising right now for some good power.
Cheers,
~Ralph
Happy New Year everyone......
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Interesting you should mention valves. For whatever reason they don't want to go back in. And I pre-drilled the bottom of the guide so there'd be no side-loading. I Had no issues when I did this to a 7mm valve head. I will look into that next week. Do you have some insight jnto this?
Honestly the ports are hardly opened up at all. Maybe 1 mm off the roof and i just smoothed the transissions in the bowl area.
I'm hoping that a dual length manifold, high compression and an extra 175cc's will enhance the low end enough to offset bigger cams
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It's hard to tell by the pic but it looks really ported but I'll take your word for it. It looks like you burred the valve guide itself not allowing the valve to be reinserted when you removed it from porting. I tend to leave the end of the valve guide in the port because it gives the valve stability and keeping it inline with its trajectory. I only see the valve guide in the port removed on race motors that are going to get rebuilt somewhat frequently and looking for every bit of flow they can get. Don't force the valve back in. Drop one in and see if it gets to the port. If it stops there then you've found your issue.
HTH...
Cheers,
~Ralph
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I'm sure there's just a burr on there as well. I would never grind down the guides on the exhaust guides or on any engine with rockers. Since these have buckets and there is zero side loading of the valve, I feel pretty comfortable with it. Removing them really makes to port look a lot bigger, as does being shinny ;) but yeah mostly just a clean-up.
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Small update. Block and pistons are back, just measured the crank and painted the block. All the mains are right at .0017" with the orig bearings. Ill need to see what the actual specs are. De-burring the guides fixed the issue. They are nice and smooth now.
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Looks good. What type of paint did you use on the block?
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A 3-year-old can that I used when I built my Datsun engine. I can get the brand for you. Probably back when paint was actually paint.
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Making sure the valves and pistons have enough clearance. The intake has .160" or around 4mm at tdc. Even If I get some huge cam with 2mm lift at tdc I should still be ok. I still need to cut exh valve reliefs since I had no idea where they went after decking the pistons and they only sit at .105". Once the final cut is made on them, it's off to the balancer. I still need to look up the spec for valve-to-piston clearance before heading back to the endmill.
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Valve to piston minimum is around 1mm I believe. I need to look it up again.
Either way, you have acres of room!
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I just read the same on MM's site. 1.0mm min and preferably 1.5mm. I should be right there. Update: head went to the machine shop to be pressure tested and have the exh valves faced a bit. I will finish smoothing the ports and grind the seats when I get it all back.
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Head is all done, surfaced and a 4-angle valve job. I would have done 5 angles but there is just not enough room to put a 15* on the top. The intake cam is out to get reground, I'm just not sure by whom. I'm also having trouble getting an exact measurement on the combustion chamber. Sometimes it comes out 33, sometimes it's 35cc. It just depends on the mood of my syringe.
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Head looks good. Funny I think I have cc'd it half a dozen times and got between 33 and 35 each time.
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I just did it 3 more times and got right around 33 each time. That puts me at 11.6:1. I'd like it just a but lower so it will be back to the end mill to take some more out of the pistons.
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Looking good!!
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33 for me too....
Cheers,
~Ralph
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It's been a long time since my last update. It's frustrating to be so tight on dough. Funds should be freed up here soon so expect this to move forward. The latest done is the rods, pistons, crank, 12.5 lb flywheel and PP are all back from the balancer. I made 360* main bearings by cutting a groove all around the lower shell. Maybe not as good as orig 360s but better than nothing. I have yet to make contact with Steve at TEP to get total seal rings lined up. Still need HG kit and intake cam reground. I will get some pics later this week. I will prob swap parts in in stages starting with the flywheel/clutch so that I can mock up the g250 to get the linkage and drive shaft worked out first.
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:D
Hi, I'm trying to finish a M42 with piston europe S50 and crank M44, could you put a picture of the head of your US piston.
Thank you.
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538g rods. 448g pistons. I don't have any stock M42 stuff laying around but they are both a good amount lighter. Final static compression ratio is 11.3:1. If anyone has suggestions on where to get rings and who could regrind an intake cam in expensively.
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Pics are fighting me. Grrrrr
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Last one for now.
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I had my intake cam reground/welded/hardened by Delta Cams. I can't remember the price of the top of my head, but you might find prices on their website.
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My intake cam is at Delta right now for basically an S50 copy. Looking for as much lift/duration without welding, just doing a base circle grind. I should have exact specs later this week.
I plan on doing a few thing to benefit the community with this so I will be installing a few things in order on my tired M42 to see the difference. First. I will install my LTW and clutch. Then, I will swap on my DISA manifold with a manual vacuum control to see the difference. My gut tells me it will flow better than the E30. Air doesn't like to stop, and the smooth bends and generous ports might actually better on the top end. Torque will be better of course. Finally, time permitting, I might put the cam in my old engine to try out too. Whatcha guys think?
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Ok. SMF conversion is done. 12.5 lb flywheel is still too heavy IMO. But it is much revvier and smoother. Like others have said it's not like night and day. Parts used: M20 flywheel lightened balanced and surfaced. Stock 325i clutch Assy. 325i bolts. Late 325i starter. Euro 323i TO bearing. Since my flywheel was machined on the back I did not use a shim behind the flywheel. I think that would be a bad idea anyways since it could compromise a perfectly flat mounting surface. Eng block to ring gear distance is identical. I highly recommend this IF it can be done inexpensively. I think it cost me around $300 total with machining and lightening. Drop $500 on this and you might be disappointed.
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The ring fairy showed up today.
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Nice! I did some nice upgrades when my engine was apart, but did not replace my pistons. To this day I regret the shop that was used for the honing and the fact that I reused the pistons. I think there's a loss of compression.
Do it once and cry only once.
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Bottom end is done. And I did a little mock-up with the head and manifold.
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Awesome, looks good glad to see this moving forward! 12.5lb flywheel is a huge improvement over stock.
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Small update. Head and exh manifold are on. Note that the victor reinz head gasket is barely large enough to clear the 86mm overbore but there are no interference issues yet. We'll see when things warm up.
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Glad to see things moving along. Did you coat the exhaust manifold with ceramic? I had mine coated with a black ceramic layer. It's held up perfectly for the past 6 or so years.
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It's a ceramic coating/paint from VHT. I've used their flame-proof paint for years and it always delivers. I painted the headers on my 510 with this and it held up very well.
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Probably won't see a M44 intake sprocket with a M42 exh sprocket together often but this engine is ready to run on either DME. Intake cam is in and both are installed and timed. Intake cam is 212deg at .050. 388" lift. I'm not sure what this translates into for advertised but I intend to check it all wit a degree wheel soon. Will find out then.
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Hi
Does look a bit odd, single or double row chain?
Cheers
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Stock double row from the M44. I'm surprised it works with an M42 head since the cams bolt in differently, but it all lines up.
Here's that 'big' cam:
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By big cam you mean your 212 deg 9.7mm? From memory!
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Well, 9.9mm but yeah I put 'big' in quotes. My Datsun cams were 13mm and 280deg advertised. 240 something at .050". But then the ports were the size of straws so getting 7k out of that engine was a bit painful.
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Everything in the foreground will be in that E30 by Monday. EWS, DME, MAF, knock sensors and all. Hope it runs.
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Nice!!
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IT LIVES!! Engine started on the second try and eventually settled down to a slightly lopey idle. Hit my IG account to see and hear it run: 320ie30
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Congrats man! Glad to hear its running!
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Awesome!! 8)
Cheers,
~Ralph
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Cool build! What are your plans for it? ITBs? Or just faster-than-it-was-stock NA street car?
I used the head and headgasket cc numbers in this thread to satisfy my curiosity for my real compression numbers, played with the calculator until I got it to say ~10:1 with the stock numbers, which left me with 8cc for the stock pistons, FWIW. Came out to 8.7:1 compression ratio with the .120" headgasket, a little lower than I would want ideally, maybe I should've picked the .098" one, but I didn't have this info when I bought it. The engine has held up and doesn't ping too terribly easily so I'm not complaining. A .3 static difference probably doesn't mean all that much for my use.
I used:
Bore: 84mm
Stroke: 81mm
HG Bore: 86mm
Compress HG: 1.6mm
Combustion Chamber: 33cc
Piston volume: 9cc
Piston deck clearance (Above): 0.15mm
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Thanks everyone. I got to drive it for the first time today. Of the entire build, on thing stands out above everything else, for good or bad. BIG intake cam. My idle quality is very lopey, and I mean as bad as my Datsun was with a 240 @ .050" cam. I double checked my timing and it is dead on factory using the tool. Now the good: 4,500 rpm comes along and oh boy the throb from the intake is near (dare I say) v-tec glorious. The combination of compression ratio and larger displacement has kept the low-end in tact, although it's not as strong at 2k as my late cam old eng. By 3k its pulling harder and just gets better from there. Might need to gopro under the hood to share the sound. Its fantastic! I suppose I might be willing to give up some driveablilty if I can improve the idle quality just a bit, but since I thinka MAF is very sensitive to intake pulses, I doubt I will be able to. I do plan to set cams using cat cams data and maybe that will help a bit.
plans are dd only, its my main form of transportation. Itb's just arent in the budget. I wonder if there is much improvement over an e30manifold. I have an e36 mani to compare once I iron out some more bugs and get it broken in.
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COP kit installed. And an update. I've pretty busy lately, but I had time to get the cop kit in. Got the a/c hooked up but it's only useable when rolling since it will kill it at idle. My idle is better and has learned up to around 900rpm. Still have some bugs tho. I have a few noisy lifters, and my guess is that they are under that reground intake cam. I'm working on the 33 lifter upgrade now and I have a set of s52/m44 beehive valve springs. Real OEM says they're the same and I saved them when I gutted the m44 head and hopefully this cures the noise, BUT I have a bad feeling that the machine shop topped the intake valves too much. I really hope I don't have to replace them but I'll try the lifters first.
I smoked the intake and it does not have a vacuum leak. My lifter issue might be compounding the idle quality what with different lifts and durations in a few cylinders. I might just need to set the cams up specifically instead of relying on the factory tool. It just idles like it has a lot of overlap.
As far as power is concerned, it is definitely stronger than the worn m42 it replaced, a good 20 ft lbs of torque. The wierd part is the top end is a bit flatter than I expected but the last time I watched the data stream it was higher than 14.7 based on the o2 readings. It will definitely need a tune. Nothing will make power that lean.
I also wanted to post some of the issues already overcome.
The h/p power steering hose fitting is 12mm and the m44 is 14mm. I used a time sert on the banjo bolt.
With a bit of massaging the e30 a/c lines work but my idle isnt stable enough to stay running. I tried 12v and grounding the ac input into to the dme withno luck. Still working on that.
The dipstick needed to be bent perfectly to weasel around the belts.
When running e30 manifolds, the iac valve on the throttle body won't fit. I tapped fittings onto the m44 iac valve and ran hoses to the appropriate ports on the manifold and e30 throttle body
The e36 exhaust manifold is just barely different (or something else is) and I had to reweld my cat. Still hits a bit over he right bump.
I made the cop harness from the e30 bits and used the afm pigtail to attach to the dme harness. Its so clean and stock looking.
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Glad to hear that it's up and running!!! Get to a dyno and see where you're at with AFR's. Keep looking for a vacuum leak if you can. You should have a good idle. If you can't find a leak then you'll need to tune it which is what I suggest anyway since it's a completely different motor now! 8)
Good luck with it and enjoy the ride....
Cheers,
~Ralph
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Glad to hear that it's up and running!!! Get to a dyno and see where you're at with AFR's. Keep looking for a vacuum leak if you can. You should have a good idle. If you can't find a leak then you'll need to tune it which is what I suggest anyway since it's a completely different motor now! 8)
Good luck with it and enjoy the ride....
Cheers,
~Ralph
its very lean at wot, like above 14.7 lean. Will absolutely need a tune. Verfied no vacuum leaks. I think that 5.2 doesnt like intake pulses at idle at all. Fuel trim is pulling back 5% at part load - maybe because of the inefficiencies of the cams and e30 inkake- and this is killing the top end when it really needs some fuel. I have a wideband sensor, I just need a guage to read it
Don't get me wrong, it has more top end than the old motor, but for an engine that was builtfor top end to be torquier thantthe outgoing means there's a lot coming in the tune. Time will tell.
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Try dialling up the vaf.
Should help at the very least with ratio providing it's running lean across the entire rpm range.
Nice work though!
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ok...I would not drive the car at anywhere near full throttle 60% or above until you get a tune. Lean = Kaboom :-\ Just putt putt it to your dyno shop.
Spend the time and dial it in on a dyno with a good tune.
Cheers,
~Ralph
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Try dialling up the vaf.
If only I had one.
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Inspirational stuff here. You're so close! Hurry it up, I need a cheap recipe for my worn out motor!
;)
Just kidding - this is a "take your time" thing that must be done right. You've made some incredible progress so far, thanks for sharing.
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No choice but to take my time, since I have little to spare. Still on the to to list are: install o2 sensor bungs for the rear and wideband. Replace tps and maybe icv. The tps reads 67% @ WOT and my idle is terrible. I think that cam has a lot of duration and that is killing the idle and may be causing it to go lean at wot also. I have the cam trays and lifters for 33mm swap waiting also. For now I will just put the intake in since there is no welding required and im pretty sure thats where the noisy lifter is.
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I realized thst I haven't updated his thread in a bit. As posted in engine management section, I have installed A SAFCII to tune. Its running on a shot-in-the-dark tune that is light years better than stock. In the long run I hope to log the data to provide to a flash tuner.
I'm lowering he compression this weekend with a 2.04 hg. Not the route I wanted to take but I think its for the best. Still will be 11:1. At the same time I will replace the topped valves and install the 33mm lifters and s52 beehive springs. I have at least one completely collapsed lifter and there are others noisy also. I'm hoping for even a bit more power after all this even considering the drop in cr, once everything is correct. I might even go m20 hunting ;)
I also edited my first post to reflect all the mods in one place.
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benz-tech,
I would leave the head gasket alone. I'm not familiar with the SAFC II but if it can only do fuel then you'll have the same problem at 11:1 compression as well. So that unit is not the answer for your build. You need to be able to control timing also. You might be looking at a stand alone unit in your near future. If you want to lower compression get a bigger cam and bleed some of it off, but you will still need a proper tune.
Cheers,
~Ralph
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It's not like it's pinging badly. Just a bit on low-rpm tip-in and only on hot days. It's nothing the the knock sensors can't handle. I just want to keep it off the jagged edge and fix a few issues while in there. Unfortunately neither a stand-alone nor 11mm cams are in the budget(although both would put it over 200 hp I'd guess) This was basically supposed to be stronger daily, but things got a bit out of hand.
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I did a comp test before removing the head and got a high of 237 and a low of 215. Turns out my exh guides/seats/valves were shot. I was very broke at the time of the initial build so I had done the seats myself (based on worn guides). Now it has new guides and exh valves, and a pro did all the machine work. S32 springs (pic. Edit: now it won't load) and bridges have been mocked up and the intake side is good. Will check the exh side too before running it as well. And more pics.
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Update time. The S32 springs, buckets, with a fresh valve job, new exh valves are all in and quiet. Along with a 2mm hg. Once everything was healthy, I got Midnight Tuning's 91 Oct tune and love it. I put a video up on IG. 320ie30 if you want to watch.
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IG. What's that? Would love to have a look.
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Instagram. It's a smartphone app. I forgot to mention that the road is actually up hill a bit also.