www.86garage.com

originally posted on C4AG w/ additional pertinent information from other responders.

went and dyno-ed at ENGINELOGICS today and here are the numbers:
hp/trq - the red dotted line in the 93+/-hp area was the stock hi-comp/smallport w/ the same carbs dyno-ed back in may of 07. the 3 dotted lines above are from today (12-18-07).

hp/afr


engine breakdown:
-"1620" 4AGE
-dual sidedraught carbs (mikuni 44phh)
-megajolt lite jr edis/programmable ignition
-pdm cams

oldeskewltoy wrote:

ASSUMPTION - 10.3 to 1 + the .8 hg = 10.7~ The silvertop slugs are higher compression then the 16V, I have little doubt the crown volume is more with a 20V slug then the 16V slug. In all likely hood you are very close to 11 to 1.

Good to kinda know... yours is now the third 4AG that I know of planting almost 120 at the wheels... ALL have compression ratios above 10.75 to 1.

Yours (by guessing) has the lowest compression and the higest hp... theirs are still using stock cams but are both at or slightly above 11 to 1.

I'm beginning to hypothesize the 4AG awakens as you approach the 11 to 1 commpression ratio, the problem is getting ignition correct. My two friends have timing somewhat adjusted to run on stock ecu.

death_blossom wrote:...the "1620" comment also leave me to believe that the displacement has been bumped up (bored out?). his setup is more aggressive than PDM's stock bluetop w/ I/H/E. although the PDM bluetop that was used was a nicely rebuilt engine, with possibly a TRD headgasket...

sorry if i've misled ya'll with the 1620 nickname. i completely forgot that we're dealing with a 1.6 (1600) liter engine. no increase in displacement. i fondly call it a 1620 because it's a 16v head(hi-comp/smallport) mated to a complete 20v block(silvertop) using an .8mm trd hg. Odncr is correct on the lift. he and i had discussed it in the past over aim. good to see you around again O!

suffice it to say, i guess my dyno numbers aren't as useful as i had hoped since they don't really isolate what the pdm cams will net you. the reason i say that is because the current motor in the latest dyno is different from the one i was running in the may of 07 example. at least you now know what my recipe is in getting 120whp.

Merry Xmas everyone :thumbup:


here's my work of "passion":








and what's currently in it (what i affectionately call a "16-20"):








unfortunately it's developed rod knock so the 16-20 will be pulled and inspected. for the time being, another complete hc sp will take its place with some slight cc modifications and oem hg.

the oil is in perfect condition and in good order. the valve train and head shows to be in great condition. going to tear down the powerplant and have it re-worked: have the head milled a bit and possibly up the valve train with new valves, guides & 3 angle.

have a new set of bearings for the 20v bottom as well as another set of rods. hopefully the rotating ass. is still in good shape and just replacing the bearings will do the trick.

anyway, there's a good deal of suspension work on the old girl: custom prescriptions and over the counters.

i'll have to list them a little later.

awesome... wish it was still together and in....

CBR_TOY wrote:awesome... wish it was still together and in....

well, if some best laid plans come to fruition in the coming weeks, it may show up again but in efi format...but we'll cross that bridge when we come to it my friend.

EFI?!?! who is this... did you forget to log out?

CBR_TOY wrote:EFI?!?! who is this... did you forget to log out?

lol!

seriously though, i've got plans to pic up another chassis in about a week. might make it an impromptu mini 86garage meet while there: fast food, catch a movie then some zzzz's.

so, in about a 8 days, the 1620 will be sitting pretty again in an engine bay.

so two 86's? very nice.... i want 2 86's....

keep us posted on the meet thing

lucky 2 86s would be awesome glw build cant wait to see the out come.

i have been thinking more about your "16-20" can you enlighten me on why you chose the smallport head?

smallport is your best friend when it comes to making N/A power.... i'm sure jonas will chime in with a high tech answer for ya which would probably be better than mine

i just heard they were better



jonas?

CBR_TOY wrote:smallport is your best friend when it comes to making N/A power.... i'm sure jonas will chime in with a high tech answer for ya which would probably be better than mine

i just heard they were better



jonas?

it's primarily due to the smallport's "smallports" :D

air velocity, venturi, however you cut it, it's the secret behind n/a flow. motorcycle motors also benefit greatly from the phenomenon. purposely decreasing the intak port to 65% of the valve size all the way to where it gets to the back of the valve.

i've also been hearing now that even in forced induction applications the smallport heads are pushing out better torque and hp numbers than the large ports. i'm still not sold yet in that arena and my short discussion with one of the guys on C4AG pushing the info didn't convince me yet.

ok thanks for the explination.

i have heard the same about forced induction but then i look at what toyota has done with the 4agze and made it smallport in the earlier jdm models and they get better numbersbut also have a higher cr

another question why didnt you use the black top bottom end since it has lighter internals?

ga_goosh wrote:ok thanks for the explination.

i have heard the same about forced induction but then i look at what toyota has done with the 4agze and made it smallport in the earlier jdm models and they get better numbersbut also have a higher cr

the 20valves also go smaller port and so do a lot of later engines.

ga_goosh wrote: another question why didnt you use the black top bottom end since it has lighter internals?

the ST bottom end was a gift from a good friend.

dr.occa wrote: the ST bottom end was a gift from a good friend.

well you cant beat free can you