In reply to TurboFource :
This what I use, 9.5mm motorcycle shims. And I had to buy lots of them....stupid 4valve V12s
In reply to TurboFource :
This what I use, 9.5mm motorcycle shims. And I had to buy lots of them....stupid 4valve V12s
A while back I shared a K24 turbo swapped 308 in progress planned to make more hp than my V12 effort.. He's got it running and 1st outing exploded the trans, 2nd outing exploded the engine. Hopefully he gets it sorted without having to drop the boost and redline to low. I'm not a honda expert so I have no idea what they will handle other than a 350-500hp guess based on the engine/trans weight. I do feel better knowing I'm not alone with 308 problems.
In other news I did some porting for a buddy years ago for a customer of his. A 308QV that he wanted to look as stock as possible so stock intake but I remover the mechanical CIS injectors and installed electric injectors. He put in a 360 crank and forgot what liners, but it was a 3.4, made 375hp at 7000 iirc, the guy who's car it was was thrilled. Not important other than he's been pinging me the last week or so and it looks like a new build is coming, 308 block, 360 crank, liners, Ti rods so 3.6 liter then 5valve heads from a 355 or 360 topped with custom cams and ITBs. I'm guessing that will make about 500-550hp at 10k if it can be built (the parts don't exacly fit together) and is what I should have been smart enough to do instead of this stupid V12 I'll share some pics as it moves forward.
I see really high rpm numbers through this thread- what is the limiting factor? I always understood it to be piston speed around 4000 ft/sec. I think the s2000 f20 has around 4800ft/sec. Wondering what the stroke of the v12 is to consider 10k rpm's.
In reply to Teh E36 M3 :
I guess its a question of how long you want it to live....drag engines routinely hit 5600ft/sec, roadrace that's not such a good idea...I tried I had a H-D with a 3.25" stroke that I figured was safe to 9200, 5000ft'sec and it was as long I was willing to rebuild it after every weekend. But shifting at 7500, 4000ft'sec it was good for a season. My V12 is a 78mm stroke so 4900ft/sec at 9500. An F360 has a 79mm stroke so its higher.....and the life at that rpm is lower I guess. I did try to talk them into a header similar to mine that would help down low but limit the peak to under 9k...no sale.
In reply to mke : It would be nice if I could find a shim kit like those!
Will have to measure my buckets, shims etc
In reply to TurboFource :
Hey Turbo, if you are still using Lotus spring retainers, the valve adjusting shims interchange with old Jaguar XK and single cam Coventry Climax. Lots of jag stuff around.
I'm rethinking my master cylinder decision and remembering why I matched them when I put this setup together... the proportioning valve is already doing too much. It is a 57% reduction, I need about 50%. The 348 with kind of similar brakes has the knee at about 400psi, about 1/3 on my valve's adjuster knob then about 50%drop after. At 57% the valve alone should be more than an optimal rear pressure reduction so I think I will end up needing to add rear bias at the balance bar, not the other way around unless I modify the valve. I need matching masters with that valve in place. Time to order another
Empi makes a 50% proportioning valve, pn 16-3157-7, I think I will replace the 57% wilwood while I'm at it.
AngryCorvair (Forum Supporter) said:It warms my heart to see people doing brake math. :-)
Well here you go then! I got tired of guessing and did some actual math. I calculated axle load as a function of braking G force, then the axle forces to go with, then converted to system pressure, put a 10% reduction on the rear axle to know the front locks first, then optimized with just mastercylinder/balance bar, then added a proportioning valve and re-optimized, then a 2nd valve, then a 3rd. The 3 valve system uses non-standard valve ratios so really just to see. The graph goes to 1.5G so slicks but I let the line cross the safe line after about 1.25G that I figured DOT race tires might give.
Its kind of an assumption on my part that matching the curves is a good thing as it should give shorter stopping distances in suboptimal conditions and also I thing should keep the car better balance comign off the brakes into turns.
I played some more and fixed a couple not quite right calculations. It looks like 5/8 and 0.7 masters are about perfect then the 50% valve then a 57% valve, and a 3rd 57% if I'm in the mood for perfection, but it does seem like if I can have 13 MAP sensors I should be able to have 3 proportioning valves . The pad cf messes with the valve setup because they work on pressure and pad cf changes system pressure.....so the spread sheet tells me where to set everything for what pad cf number.
Now I need to decide if I need to add transducers and log brakes or just buy a couple gauges to do the setup....I need to go back there the ECU setup info, its been a while and I'm not sure what all is still available and what extra wiring I ran or if I would need a CAN expander or some such.
It looks like analog inputs AN21 and AN22 are available . Light gray is what AEM used them for and I try to follow when I can going back to when I wasn't sure my program would would correctly and thinking I could reload theirs....I now know only they can load their firmware but it was a good thought.
And I have 3 2-conductor shielded wires. 1 I want to save for a front CAN line but I could use the others 2 and send 5V and ecu gnd up 1 and the 2 brake pressure signals back in the other. I have 3 unshielded wires too but I like to keep analog signals in shield wires anytime I can and I have them sitting. There is a 4th, I think 3 wire under the dash on the by the steering wheel planned for steering angle.
Anyway, it looks like front and rear brake pressure transducers are a go and I'm kind of eying CAN accelerometers but I think I'll hold that thought until the car is actually driving and just use a phone app to setup the brakes for now.
I thought this weekend was brakes......but brakes can wait since the head shims/rings arrived a week early and they look marvelous!
The pin holes were a little tight
but now fit. I hadn't ordered the orings knowing thinking there was time, but did last night when I got the shipping notice for the shims and they will be here tomorrow so I can assemble and get it on leak test Saturday maybe
The heads are on
The o-rings were not as easy to install as I'd imagined but but the aviation sealant mostly kept them on place
Then inspect and set the head on. The 518 sealant I used on the coolant pipe test covers needs time to dry before I can pressurize, but I did put in 5 psi to make sure the orings stayed put and that is holding
My thought today is since I'm now counting on sealant everywhere but the cylinders, it could be leaking anywhere.....and I have a brand new tube of 518 sealant that now seems ideal. I like the idea of high temp RTV too, but there is no way I can assemble this in 5 minutes. A quick google of slow set RTV upped up form-a-gasket 2a...the thick version of aviation sealant.
I'll start with 518 and see what that does I guess.
[quote] The 518 sealant I used on the coolant pipe test covers needs time to dry before I can pressurize, but I did put in 5 psi to make sure the o-rings stayed put and that is holding[/quote]
So I knew the sealant needed time and I didn't wait.....for sure the sealant on the gage plate blew out while I was in side cleaning up. It holds no air now and I hear/feel it at the plate. When I popped the plate off there was a clear channel.
This means I have at least a temporary reprieve The plate is resealed, hot air gun deployed to speed things along.
The heads are sitting just a little lower now and one is hitting the oil filter adapter and I can here a small leak right there.
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