Discussion: Blacktop 20v: The road beyond 200hp

[Billzilla]

Bill what is max lift i can run is 10mm ok? and if not will radiusing the edge of bucket do the trick.

Not really sure, but it depends on how aggressive the ramp angles are on the lobes really. You'd have to try them on the head, and turn them over slowly by hand to see if they hang off the edge of the bucket at all. Also give some Prussian Blue a workout on them, it'll help you see wipe areas you can't see by eye.
There's been a few people who have run big cams, so they would know better than me as to how far to go.
(And this is why my new head has 31mm buckets. )

[oldcorollas]

yeah thats the only real difference that im aware of. the facelift ones are a far better match to the ports in the head. how about a pic that shows that.

no worries...
can anyone get a picture of the ports in the head, with a metal ruler right next to the ports?
then we can measure the cross-sectional area and overlay to the manifold pics....
i will do tonight (my tripod and ruler is at uni )

[Celica RA45]

the only way you are going to get 200 hp is stroke it with a 7a crank and use the block and bore it out so have 1900 cc with 20 valve head and some 48 mm quads and 10,7mm lift cams that trd made and also there valve springs ,so custom rods and forged pistons ,with no vvt and about 11.8 to 1 comp and a decent set of pipes ,thats it there it is, no pissing comp or i have a bigger dick than yours but i cant show you etc also you wont be able to go over 8000 rpm as the crank wont like it unless you go billet crank allow about 4000 for that 1

[86er]

the only way you are going to get 200 hp is stroke it with a 7a crank and use the block and bore it out so have 1900 cc with 20 valve head and some 48 mm quads and 10,7mm lift cams that trd made and also there valve springs ,so custom rods and forged pistons ,with no vvt and about 11.8 to 1 comp and a decent set of pipes ,thats it there it is, no pissing comp or i have a bigger dick than yours but i cant show you etc also you wont be able to go over 8000 rpm as the crank wont like it unless you go billet crank allow about 4000 for that 1

Hi glen thansk for reply can you explain to me why u think the 1800cc bottem end is needed to exceed the 200 hp ( are u refering to 200 crank hp or wheel hp?) I persoannly see the 7age bottem end as a hinderence with na as like you said crank cant take rpms and thats where power will be made past 8000 most likely. also Im assuming u mena wheel hp as i have posted the infor shouwing people gettin 200 and up or over 190 cranks hp with 1600 bottem end so please clarify thanks

[ed]

ive just read back through this thread, and after considering the scores of complaints about the behaviour on here, im deleting everything thats irrelevant, and neg repping everyone who stuck their head out in the technical section for non technical reasons.

end of story, no complaining, no PM's, just shut the fuck up and grow up - everyone

[86er]

found it on another forum originally from club4ag

Originally Posted by Mr.John
so as i pulled apart my new blacktop i couldnt beleive the differences between the silvertop. i could talk about it all day but pictures work best.






the first thing i noticed was the port sizes and the itb size, but the first really surprising thing i noticed was the cams. they have a severely lighted deadside and also a narrower contact area also.



heres them compared to the silvertop cams!




so after that i pulled the block apart and pulled the pistons off and weoghed everything. heres the results.


blacktop rod w/no bearings:



silvertop w/no bearings:



another silvertop rod i found that weighed different w/no bearings



silvertop piston w/rings:



blacktop piston w/rings:

[86er]

continued more info

check this out, the blacktop wrist pins are machined on the ends and weight less than the silvertop pins!

blacktop pin:



silvertop pin:



another thing i thought i would throw in is the difference between the 16v and 20v oil pumps. the 16v is on top:




from what ive found there where two versions of the silvertop. the early model had a different itb manifold and itake port shape. heres a pic of the old manifold:



heres the newer silvertop intake manifold:



and heres the blacktop, notice the very different shape. not as tall but much wider:



heres the measurements of the silvertop:



okay another big difference was the exhaust port size. the blacktop is just like taka said. 2mm larger than the silvertop:


silvertop:



blacktop:



okay. also another big change is the combustion chamber shape. the blacktop is very smooth with almost no place that can be called a "hot spot" or some place where detonation is likely to occur. the silvertop on the other hand has three protruding edges.

silvertop: the bottom of this chamber was also smothed out by me to try to remove the hot spot.

[86er]

continued again I removed last picture as it wasnt relevant and theres a limit per post

blacktop:




next theres the intake port. the silvertop is taller but not as wide. also down in the port the silvertop has almost nothing dividing the three valve ports. however the blacktop has three distinct runners seperating the valves. also the port is much wider.

silvertop:



blacktop:



heres a few pics with measurement:

blacktop:



silvertop:



well the last thing i can think of is the diameter of the throttle body inlet so heres the two:

blacktop:



silvertop:



oh one last thing i noticed, the blacktop has a mechanical timing belt tensioner where as the silvertop just has a spring and then is tightened down. heres a pic of the blacktop tensioner:



then a few more random pics:




um.. i didnt remove the cranks to weigh them but i might do it later. i dont think there is a differnce though. if you guys have any questions or want me to weigh/measure anything else let me know soon before the things back

[takai]

i thought that 20 v that made 130 something was a 7age stroker out to 1900 cc ,well thats what i was told

That would be Loftys engine, and that makes a whole lot more than 130 something. Its up near Jowetts engine in hp output, and just loses it slightly on the straight.

[Sam_Q]

heres a picture of the difference between the combustion chambers on the two heads:




why they changed the squish areas would have to be the single thing that confuses me the most of all the chanes that were made.

Also heres a question for you guys. Officially the blacktop has a different cam gear belt drive profile, more sqaure or something. But when I compared them they were identical, how is this possible?

[Mr Revhead]

the belt drive profile is the same, BT has one (iirc) extra tooth.

BT and ST cranks are the same

[Sam_Q]

I thought it was 2 teeth?

heres one for anyone who is sick of the hydraulic tensioner stuffing up on a backtop: change the oil pump and tensioner to one off a silver and then you run a silver belt (Gates T811), problem solved

[Celica RA45]

i havnt seen any 1 get more than 185 hp at the flywheel .16v motor on a engine dyno made 185hp power was from 6500 to 8500 rpm and i think a few people overseas have done black top motors with about the same hp with alot more develop ment .the thing is the 20 v has had a lot more time spent on it to make more hp and also with vvt to make the 160 hp quoted from factory with the quads etc .
when they race them with all the extra parts and no vvt i suppose it becomes a bit of a compermise .
but if you stroke with the 7a block and crank and bore it ,there talking about 220 hp at 8000 rpm, well thats speed racers claim on his web page ,he seems to do quite a few of these motors at www.speedracersportscars.com.au so have a look thats about all i can help you with ,just a side note silver top motor on engine dyno 138hp
black top motor 144 hp on same engine dyno on the same day

[86er]

i havnt seen any 1 get more than 185 hp at the flywheel .16v motor on a engine dyno made 185hp power was from 6500 to 8500 rpm and i think a few people overseas have done black top motors with about the same hp with alot more develop ment .the thing is the 20 v has had a lot more time spent on it to make more hp and also with vvt to make the 160 hp quoted from factory with the quads etc .
when they race them with all the extra parts and no vvt i suppose it becomes a bit of a compermise .
but if you stroke with the 7a block and crank and bore it ,there talking about 220 hp at 8000 rpm, well thats speed racers claim on his web page ,he seems to do quite a few of these motors at www.speedracersportscars.com.au so have a look thats about all i can help you with ,just a side note silver top motor on engine dyno 138hp
black top motor 144 hp on same engine dyno on the same day

Glen take a look at this
http://64.233.179.104/translate_c?hl...language_tools

Note that with 272 todas and vvt disabled they got 201ps which is just about 197bhp

[SRacin]

Interesting,

Well Im about to go down the modify a blacktop path.
Standard blacktop, open trumpets slight exhaust, bit of avgas and lotsa timing made 130hp at wheels on a dynapack hub dyno.

Bit's im going to be throwing at the engine include
Cams- Toda - in 288 w/ 9mm lift ex 272 w/ 8.5Lift
Cam Gears - Toda-
Valve Springs - Probably Performance springs (yet to be purchased)
Computer - Link LEM G3
Exhaust - Hi Rise close as poss to equal length 4-1's ~850mm primary length into resonator and side exit exhaust
Head - 1996 Blacktop - Ported, cleaning up and flow (to what level yet i dont know yet)
Block - blacktop pistons, silvertop rods (may stress relieve em if i can afford to), balanced and freshened up.
Trumpets-Some form of trumpets (not factory) into a large airbox for cold air.
TRD Head Gasket & Mega Compression, TBC

And thats pretty much it. Will be running it on avgas only. Now take bets as to how much gain i can get over my 1st dyno run with the standard engine.