delta_88_germany

hey
i got a 73 delta 88 with a 400 pontiac engine with 130kW but it seems that there is way to less power. I even canīt do burnouts. and it feels liek the power comes just with high rpm

on stock was a 455 enine installed.

so its is a pontiac formula 400 engine code 481988 and 5C heads
with a edelbrock 1406 carb

Any ideas hpw to incease that?
Edelbrock intakes ?

alex

Professur

First thing would be to check compression and make sure it's not just worn out.

cutlassefi

The 5C heads are normally some of the better ones but there's no telling what piston is in it.

Do the usual, compression check, timing etc and go from there. You may also want to verify the rear gear ratio.

An aftermarket intake may help but it won't make it a barn burner if there are other issues.

delta_88_germany

hey
thanks for the fast reply. i bought a compression check meter today on ebay.
will check all cylinders next days and post the result here.

is there a sheet how much the compression should be ?

i just saw that pre 1970 pontiac 400 engines hast a lot more power than after 1970

what are the chanes they made ? shorter rods for low compression and smaller valves ?

oldcutlass

A fresh power tune up would probably help a little bit.

delta_88_germany

its a th350 i thought gear reatios are the same

http://www.hotrod.com/techarticles/t...n_tuning_tech/

may a th700-r4 sould improove start up acceleation and lower fuel economy

alex

oldcutlass

Power is not going to be gained through mods to your transmission. The gear ratio references that others above mentioned are for your rear axle. A 700R4 alone will not gain you much performance but will help overall fuel economy.

joe_padavano

While the trans doesn't increase HP, it DOES help with off-the-line acceleration. First gear in the TH350 is 2.52:1. First in the 700R4 is 3.06:1. Assuming the D88 has a 2.73 rear axle, changing to the 700R4 is the same as changing to a 3.31 rear axle with the TH350. That WILL make a noticeable difference in a heavy car like the D88.

Of course, reinstalling a 455 will also make a noticeable difference...

firefrost gold

5c's are a large chamber low compression head 100cc i think about 7.6 on a 400 not the greatest for a big car. The stock pontiac intake is very good but heavy . With the 1406 you must have a plate on it to adapt to the square bore or a aftermarket intake ? The edelbrock performer would be the best way to go it will save some weight but otherwise no need to change out. If all checks out good a real good tune up as stated above with new wires and points with timing set should help . I had a 400 2.56 gears and a small cam I had no problems
getting things rolling with my pontiac . Good luck.