*7M Crank RPM Limit*
- Thread starter IJ.
- Start date
Any of you guys have information on BLKJET the MA70 that put down 565rwkw@10500rpm at Melbourne Autosalon a couple of years ago? My ears felt like they were going to start bleeding it was screaming so loud lol, unfortunatly I don't know any of the specs, I used to have an article in an old Fast Fours. The owner just went to an engine builder with a wad of cash and said "Make it go fast." 
Found the article again, here’s the list of engine modifications,
Bottom end:
-Block decked
-Torque plate bore and hone with plateau brush
-Custom Argo I-beam conrods with 2000 series ARP rod bolts
-Ross full floating forged pistons
-Perfect Seal gapless rings
-ARP head and mains stud kit
-Crank stress relieved, cross drilled, Tuftrided and index ground
-Main tunnel align honed and internally balanced using Mallory metal
-The blocks oiling system has been blue printed and indexed to bearing clearances
-Heavily modified oil pump to cope with 10,000+ revs
-Final short block assembly blueprinted and clearenced accordingly
Head:
-Hardened and annealed standard valves with a seven-angle valve seat face
-Countless hours of port work developed on a flow bench
-Cams are aftermarket and a closely guarded secret :rollseyes:
-TRD valve springs
-HKS 1.0mm head gasket
-8.5:1 comp. ratio
Bottom end:
-Block decked
-Torque plate bore and hone with plateau brush
-Custom Argo I-beam conrods with 2000 series ARP rod bolts
-Ross full floating forged pistons
-Perfect Seal gapless rings
-ARP head and mains stud kit
-Crank stress relieved, cross drilled, Tuftrided and index ground
-Main tunnel align honed and internally balanced using Mallory metal
-The blocks oiling system has been blue printed and indexed to bearing clearances
-Heavily modified oil pump to cope with 10,000+ revs
-Final short block assembly blueprinted and clearenced accordingly
Head:
-Hardened and annealed standard valves with a seven-angle valve seat face
-Countless hours of port work developed on a flow bench
-Cams are aftermarket and a closely guarded secret :rollseyes:
-TRD valve springs
-HKS 1.0mm head gasket
-8.5:1 comp. ratio
Point of reference..
Stock crank
Je .40 over pistons
Crower rods
Shimmed oil pump
Balanced rotating assembly
Clevite bearings
Stock cams
Comp cams valve springs
Crower rod bolts
Arp main studs
All specs lean toward tighter end of spectrum
My electronic revlimitor is set at 7280, and I constently bounce off the limiter, mabye bouncing off it anywhere from 5 to 15 times before a shift
Motor has yet to let lose, but it did snap a stock rod at only 62xx rpms in 5th gear. Its evidential that it was the stress of extreme load at moderate to high rpms in the highest gear that snapped the rod, not the high rpm limit
Stock crank
Je .40 over pistons
Crower rods
Shimmed oil pump
Balanced rotating assembly
Clevite bearings
Stock cams
Comp cams valve springs
Crower rod bolts
Arp main studs
All specs lean toward tighter end of spectrum
My electronic revlimitor is set at 7280, and I constently bounce off the limiter, mabye bouncing off it anywhere from 5 to 15 times before a shift
Motor has yet to let lose, but it did snap a stock rod at only 62xx rpms in 5th gear. Its evidential that it was the stress of extreme load at moderate to high rpms in the highest gear that snapped the rod, not the high rpm limit
Adjuster
Supramania Contributor
I think the Eman has the highest recorded rpm at 7190 on the stock TCCS. (Missed a shift while boosting... engine just spun up to that rpm from the stock rev limit for the 6M crank.)
My crank is not stock however It has 97.5mm of stroke, 327sbc rod journals spinning Pauter rods swinging ROSS pistons. (I belive the bearings are Clevites for the 327 rod size.) Mains are stock sized for the 7M, from Clevite as well.
Entire deal was balanced. Oil system is slightly customized (Shimmed and ported pump, converted the crossover pipe to a full AN10 setup, removed the stock oil filter location, plugged the block and I'm using an external set of filters, and the oil cooler from a RX7 also converted to full AN10 sized fittings with the thermostat built into it. Accusump is in the rear hatch being used as my subwoofer grille.)
Valve springs are the Comp Cams BBC inner ones. Just for fun, we took a stocker from my engine, and tested it compared to the CC ones. The BBC springs are taller and slightly bigger around than the stockers. The wire size is smaller however, and the coil bind height is much better than the stock spring. I don't have the figures, but based on just eyeballing it, the stock springs would bind with any cam that has more lift than stock. (You have a few mm to play with, but not much more.) At the same installed height, the Comp springs had tons of room before they would bind. (You could run a huge lift cam and not have any coil bind issues, but without shimless buckets, it's a moot point.)
Pressures were the real reason I changed the springs. (That and they were totally less money than OEM springs new.) I don't remember the exact numbers, but the springs were in the range seat pressure wise as the 2JZ upgrade springs from Comp, but not so high they would cause seat wear issues.
Best less than 70.00 I've spent in many years... LOL
If I ever get a standalone, or re-clock my stock TCCS for a higher rpm limit, I'm thinking 7500rpm would be fine, and possibly even 8k is the upper limit for this setup. (Stroked that is.)
My crank is not stock however
It has 97.5mm of stroke, 327sbc rod journals spinning Pauter rods swinging ROSS pistons. (I belive the bearings are Clevites for the 327 rod size.) Mains are stock sized for the 7M, from Clevite as well.Entire deal was balanced. Oil system is slightly customized
(Shimmed and ported pump, converted the crossover pipe to a full AN10 setup, removed the stock oil filter location, plugged the block and I'm using an external set of filters, and the oil cooler from a RX7 also converted to full AN10 sized fittings with the thermostat built into it. Accusump is in the rear hatch being used as my subwoofer grille.)Valve springs are the Comp Cams BBC inner ones. Just for fun, we took a stocker from my engine, and tested it compared to the CC ones. The BBC springs are taller and slightly bigger around than the stockers. The wire size is smaller however, and the coil bind height is much better than the stock spring. I don't have the figures, but based on just eyeballing it, the stock springs would bind with any cam that has more lift than stock. (You have a few mm to play with, but not much more.) At the same installed height, the Comp springs had tons of room before they would bind. (You could run a huge lift cam and not have any coil bind issues, but without shimless buckets, it's a moot point.)
Pressures were the real reason I changed the springs. (That and they were totally less money than OEM springs new.) I don't remember the exact numbers, but the springs were in the range seat pressure wise as the 2JZ upgrade springs from Comp, but not so high they would cause seat wear issues.
Best less than 70.00 I've spent in many years... LOL
If I ever get a standalone, or re-clock my stock TCCS for a higher rpm limit, I'm thinking 7500rpm would be fine, and possibly even 8k is the upper limit for this setup. (Stroked that is.)
tubbie said:
This was the initial tune of the motor without the HKS Cams (not installed) and with 550cc injectors/Walbro Fuel Pump...essentially we were trying to make sure it ran.
Anyway, computer control system is Autronic SM2 with MSD Dis-4 - Dual post coils etc etc etc
Built motor. Nothing special about it except for the headwork.
Car made 410rwhp @ 14psi. Power started cutting off around 5500rpm.
Next dyno hopefully will be with new fuel system, cams and more boost (Once I find a location to start installing them and some help on some things).
If you have any other questions...let me know
Considering that Ryan woon is doing 9.5k RPM on the 94mm strokes 2jz crank. I don't see why the 97mm storked could not be spun to 9k (which will be might goal, pictures to comes if the motor grenades )
)
group a supra
SPAWNING AN INTERCEPTOR
figgie said:Considering that Ryan woon is doing 9.5k RPM on the 94mm strokes 2jz crank. I don't see why the 97mm storked could not be spun to 9k (which will be might goal, pictures to comes if the motor grenades
ryan has a billet crank so a little bit different figgie
group a supra said:ryan has a billet crank so a little bit different figgie
Machined steel or cast steel.
it is ALL about balance to within 1gram
Update!
My 7M full counterweight Crank has been to 7700 probably 100 times now with no ill effects!
I plan on pulling the motor for inspection once my final tune is done so will be able to gauge if there is anything further that needs to be done for longevity.
My 7M full counterweight Crank has been to 7700 probably 100 times now with no ill effects!
I plan on pulling the motor for inspection once my final tune is done so will be able to gauge if there is anything further that needs to be done for longevity.
group a supra
SPAWNING AN INTERCEPTOR
cool then when we have mine running we start a new thread like this or continue this one on the group a 6m crank lmao
will be intresting to see if there is anything that needs resolving ian
will be intresting to see if there is anything that needs resolving ian
heheh very nice mate
The fully counter weighted crank came in the later model oil squirter block correct? and isn't stamped with 6M or 7M correct? I ask because my mates OS block has a 6m stamped crank, as do both my OS and non-OS blocks, is it likely our counterweighted cranks have been replaced in the past?
The fully counter weighted crank came in the later model oil squirter block correct? and isn't stamped with 6M or 7M correct? I ask because my mates OS block has a 6m stamped crank, as do both my OS and non-OS blocks, is it likely our counterweighted cranks have been replaced in the past?