7M stroker build
- Thread starter mk3ukr
- Start date
I would be pretty anal about the tolerances on the bearings. Since the 7m already has a long stroke, making it longer has a larger chance of spinning a bearing. I know, because of not only my engine builder warned me when i was building a 427 small block, but because my step dad has had the same thing happen after two years in his drag car.
Mains are 0.00314', big end 0.00275', and I plan to use w50 oil after running in motor on mineral oil. I think about 5w50 or 10w50 synthetic oil.
Today fitted all pistons, to my big surprise deck height is higher then my expected 0.3-0.4mm figure. Measurements are:
#1 - 0.65mm
#2 - 0.50mm
#3 - 0.62mm
#4 - 0.57mm
#5 - 0.60mm
#6 - 0.63mm
I have 0.060' head gasket, if I knew I would have ordered 0.065'
My smallest piston to head distance will be 0.87mm (0.0343') on #1. I think I should be just fine, though having PTH distance 1.0mm would be more comfortable. Some V8 guys run it 0.030' at 6.0-6.5K rpm. I want 7500 rpm redline, but my pistons are lighter then V8 pistons and don't stretch rods as much.
Static CR will be average 8.8:1
I wanted to fit front and rear covers on RTV but decided not to use it. Can be big problem in the future to separate covers from the block.
Turning torque of rotating assembly 9 Nm = 7 lb-ft
#1 - 0.65mm
#2 - 0.50mm
#3 - 0.62mm
#4 - 0.57mm
#5 - 0.60mm
#6 - 0.63mm
I have 0.060' head gasket, if I knew I would have ordered 0.065'
My smallest piston to head distance will be 0.87mm (0.0343') on #1. I think I should be just fine, though having PTH distance 1.0mm would be more comfortable. Some V8 guys run it 0.030' at 6.0-6.5K rpm. I want 7500 rpm redline, but my pistons are lighter then V8 pistons and don't stretch rods as much.
Static CR will be average 8.8:1
I wanted to fit front and rear covers on RTV but decided not to use it. Can be big problem in the future to separate covers from the block.
Turning torque of rotating assembly 9 Nm = 7 lb-ft
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Today nearly finished mottor assembling, have only to tighten head stud nuts and do some small things like timing belt, cam position sensor, etc.
Previously I used ARP head bolts, box wrench 13mm, now with my new head stud kit I found today I need long 14mm 12-point socket. All shops were closed, will buy it tomorrow.
Fabricated flange and welded Wilson pressure relieve valve to intake manifold
Wrapped exhaust manifold with thermal insulation. Shit, it needs more then 20 metres of thermal tape!
Previously I used ARP head bolts, box wrench 13mm, now with my new head stud kit I found today I need long 14mm 12-point socket. All shops were closed, will buy it tomorrow.
Fabricated flange and welded Wilson pressure relieve valve to intake manifold
Wrapped exhaust manifold with thermal insulation. Shit, it needs more then 20 metres of thermal tape!
Hmm.. Please don't take this the wrong way as it seems that you are very maticulously building that engine and props for that but a stroked 7m? Was that not one of the main problems with the 7m design in the first place? (That it had to long of a stroke).. There might be a reason why there are only 3 stroked 7m's.. Also there might be a reason why Toyota fixed the 7m with the 1j. and 2j. which both have shorter strokes.. Hmm but to each his own and I personally hope that this works out for you because I would hate to see all that work go to waste... Best the luck..
NokaoiMK3;1392407 said:
well I will answer.
it is not the stroke. After all the S54 has the same exact stroke as the 7m and the spin that motor to 8k rpm from factory
The reason that there is only three stroked 7m, money. $5k just for the short block. Add coatings etc and can jump to 7k. There is a reason you don't see people plopping down 12k on the LS7 long block
NokaoiMK3;1392407 said:
Stroking has it's pros and cons....most all big power 2j's are stroked! Stroke has nothing to do with the 7m issues...it's issues are it's age, it's headbolt torque spec, and it's oiling system! Stroking let's you use as much power as each bang will let you instead of wasting expanding gasses threw the exhaust...it limits your rpm in stock form but he did have custom pistons ordered to handle the stress and with good rings he can handle higher piston speeds...7500rpm is alot! Yeah sucks he won't ever see 9000 rpm but it don't matter....as long as the build is good the motor should last and for drag racing generally stroking is the way to go!
Good replies^^ Lighter pistons, rods, knife edged crank, anything to lighten the rotating mass helps with the increased piston speeds.
I think there are 4 strokers out there and another 101mm stroker by Definant that was being built but he has been MIA for a while now, don't know if he finished it or not.
Looking good Vadimir.
I think there are 4 strokers out there and another 101mm stroker by Definant that was being built but he has been MIA for a while now, don't know if he finished it or not.
Looking good Vadimir.
Today nearly completed assembling motor, tomorrow it will be finally in the engine bay :icon_bigg
I checked with putty valves to pistons distance in the worst case scenarion (broken timing belt). It is difficult to measure it correctly, I estimated it 1.0-1.2mm for intake valves and 1.5-1.7mm for exhaust valves.
I have 7.9mm lift cams, next year want to buy billet cams from Rich. Not something crazy, like 11mm lift, 280deg duration. I am thinking about 9.5mm lift, probably staggered 268/272 deg.
Few pictures of motor, every time I see this turbo I am scratching my head and ask myself how it is going to spool :biglaugh: I remember one street driven 7M mk3 in Malta with 88mm Y2K turbo and Powerglide. I hope with my stroker it will be not very bad.
I checked with putty valves to pistons distance in the worst case scenarion (broken timing belt). It is difficult to measure it correctly, I estimated it 1.0-1.2mm for intake valves and 1.5-1.7mm for exhaust valves.
I have 7.9mm lift cams, next year want to buy billet cams from Rich. Not something crazy, like 11mm lift, 280deg duration. I am thinking about 9.5mm lift, probably staggered 268/272 deg.
Few pictures of motor, every time I see this turbo I am scratching my head and ask myself how it is going to spool :biglaugh: I remember one street driven 7M mk3 in Malta with 88mm Y2K turbo and Powerglide. I hope with my stroker it will be not very bad.
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you will need a sign telling people to keep their hands and small children away from that turbo. wow.
does the turbo manifold leave enough clearance for the oil filter, or are you relocating that?
does the turbo manifold leave enough clearance for the oil filter, or are you relocating that?
IJ.;1352659 said:I'd be interested in a pair of arms Vlad
Make that 2 of us!
It's nice to see a build that isn't just someone's "1,000hp dream" (Which pop up in this section all the time). I will be watching this build, GL.
7Mboost;1393643 said:
It is still half-dream, rest of the car is not ready to handle this power.
I will send PM regarding arms cost
Worked till after midnight today (or yesterday). It is PITA to put this motor into the engine bay. Previously I used to fit motor with tranny connected easily alone. Today it took me 3 attempts to realise there is no way to do it with transmission connected. Engine mount pads get on the way of exhaust manifold runners. I had to disconnect transmission and fit motor alone
IJ.;1388782 said:Ahhh I see
Local delivered cars here have big ass folded beams inside the doors.
It depends on the year. My Eurospec 1992 has side impact protection. My friends 1987 doesn't have anything.