How far should I try to go with a stock 86 TI bottom end?

[Clay]

We all know the stock 86 TI bottom ends are pretty weak, more or less. They do ok with basic mods, but when your wanting to push past ~250 HP, your basically pushing your luck.

I think Im to a point where everytime I make a pass Im pushing my luck.

I figure with every mod I make Im pushing it that much further.

current mods are limited for the most part. Basically stock 87 TII top end (mildly ported 2 piece), 3" TU SV and DP, +20s, 87 electronics with 3bar, running 20 psi. This is through a stock 89 Daytona IC, and a 520/555 hybrid trans w/ stock TII/TIII clutch setup.

Future plans include a large FMIC, T3/T4 hybrid, new TU log manifold, alky, +40s w/ a new cal (thanks matt!), etc etc.

Ive been holding off doing much more becuase I figure just adding a FMIC could put me over the edge and BOOM there goes a running car Im pretty much at a cross roads...... do I keep trying to go faster with a stock 86 bottom end, or do I quite where I am and just build a common block?

I do plan to build a common block eventually. Ive got an 89 TII common block, TII rods, and a set of new weiscos..... I plan to start that ball rolling sometime this winter anyway.....

so... thoughts?

[Turbo Joe]

i had that exact block in my car, but i had the MP billet mains and arp everything with a forged crank and forged rods then grp rods.. i've discovered that the block it's self isn't strong enough to go past 300 whp and last. I've gone past the 300 whp mark by far, i made it to the 340 w/375 ish torque. but when my pc crashed i lost my maps that i didn't save and my ecu was at FAST getting the inj drivers repaired, so i didn't have a map in it when i sent it to them.. i went back to the dyno to re tune the car and spanked the motor at only 310 whp w/340 torque.. so you chance it everytime...
have a massive oil cooler and frequintly change the bearings, But your all stock and your making 250 whp? your lucky its still together now...

[Turbodave]

I do plan to build a common block eventually. Ive got an 89 TII common block, TII rods, and a set of new weiscos..... I plan to start that ball rolling sometime this winter anyway.....

so... thoughts?

I say build the common block, and in the mean time beat the snot out of the TI that's in there. T-M karma is such that if you have a spare engine ready to bolt in, the one in the car will never fail.

[cordes]

I say build the common block, and in the mean time beat the snot out of the TI that's in there. T-M karma is such that if you have a spare engine ready to bolt in, the one in the car will never fail.

+1 there.

Also, I would ask JT, as he seems to be very confident in his shadow's motor, which I believe has the LW rods.

[jamesmonty]

I say we see how much it can take at the spring fling! You got a tow dolly right?

[Clay]

oh yeah, I got a tow dolly! I guess I can keep upgrading everything. Spring fling will be the first time I get it out next year. Palooza was the last time this year. At a minimum it will have a bigger IC, stiffer rear end, alky, and a different cal.

[BadAssPerformance]

+1 there.

Also, I would ask JT, as he seems to be very confident in his shadow's motor, which I believe has the LW rods.

'87 T1 FTW!!!!

It all depends on the day the rods were made, my heavy Shadow should be at ~ 250whp to run 12.89 @ 104.5, well over 100 passes on it launching at ~5000rpm+... I cross my fingers before each run tho.

A friend has a '87 GLHS (45k miles, original owner) and a rod let go while driving home from getting new tires

Why his motor instead of mine??? I feel so bad for his car and think that it is not just that his expired and mine didnt. Not that I am hoping mine does, just saying that this comparison means that anything can happen...

[Clay]

But your all stock and your making 250 whp? your lucky its still together now...

well, who knows what its making, but I think that should be somewhere in the ballpark. Went 13.1 with it my first trip to the 1/4 mile, at what to me was a slower track. Never did get the same 60's I do at home, nor did I get the same 1/8th mile times. I was always at least 0.1 off on the 60', and .2 off on the 1/8th mile. SO I figure that would at least put me at a 12.9 on a good pass, which is close

[Clay]

Why his motor instead of mine??? I feel so bad for his car and think that it is not just that his expired and mine didnt. Not that I am hoping mine does, just saying that this comparison means that anything can happen...

your right JT... you just never know I guess.

Between this year and last year Ive lost 10 psi of compression across all 4 cylinders. Not bad for the stock original engine with over 100K miles on it

[BadAssPerformance]

I used the Shadow for most of the summer as a true daily driver. Using a MP S2 cal and 42pph injectors and 100 octane it ran RICH at idle. Sitting in traffic daily I would notice that it would idle at ~10-12 inches instead of the 17-18 inches it usually idles at... change the oil, get it on the open road, whoop on it a bit, all is good again, LOL

[Marcus86GLHS]

".......so... thoughts?..........."


you got a great combo as it sits. enjoy living on the edge.
:-)

[1FastCSX289]

You could always go with the Donovan approach and push it as far as it will go, blow it up, and buy another 100 dollar j-yard motor for it........and blow it up again!

But, I think I would build the other CB engine, let it sit on the stand.....and then mod the T1 until it lets go. It would be a cool experiment to see how far you can take it.

For the record, I blew up a stock 87 T1 lower end at 14 PSI (intercooled T2 set up and MP logic module). It was totally stock. A rod just let go and made a giant exit hole in the side of my block. Oh well. I bought another motor for 50 bucks, changed the bearings and put it back in the car.