Built a 355 for my son on a budget and it ran 12.63 @ 108.41 mph over the weekend. See how we did it. 1985 trans am

First try with budget motor:

-355 sbc
-stock set of high mileage vortec heads I tore apart, inspected, did a mild bowl blend and put them back together pitted seats and all with alexspring kit. I did do a light lapping of valves to be fair. bolted them on with steel shim gasket.
-piston are cheap rebuilder pistons .037 down the hole and the .015" shim gasket. compression 10.2 to 1, quench .052"
-234/244@ .050" hyd ft cam .488/.510 lift 112 ls
- normal stuff, cheap gasket kit, stock oil pump and stretched the spring, bi-metal bearings, double roller timing chain.
- Intake is the air gap knock off, what junk, but it's on the engine
-carb 600 VS holley ,14x3 air cleaner
- shorty headers open at the track
- stock rockers and pushrods
- pieced together hei unit with super fast curve 32 total all in by about 1500 rpms, rock solid 22 degrees at idle 700 rpms with 10 degree vacuum can-hooked to full port vacuum.

-tranny is a th350 with a Jegs 10" 200 dollar converter 2700 rpm one.

-2.73 gears and 26" tall slicks

This combo was good for 13.69 @ 103 mph with 2.07 60ft times

made a change:

swapped the 600 vs holley to a 750 vs holley 3310-2 and ran,

13.59 @ 104.41 mph with a 2.06 60 ft time

made another change:

swapped the shorty headers for full length 1 5/8" headers ( still open), swapped stock rockers for 1.52 roller tips, changed stock push rods for .080" walled. Plus changed the 2.73 gears for 4.10 gears

13.01 @ 106.5 mph 1.82 60 ft


made another change:

traction was horrible, replaced the lca, installed new lca relocating brackets, installed new panhard bar, installed new summit racing g7700 racing shock in rear, yanked the front sway bar and installed new 14" x 3" filter ( the other was old and dirty) fixed a minor fuel leak at pump.

at the track the car was running out of fuel on the first few runs near finish line, still running 12's but mph was down, i cranked up the front and rear fuel bowl levels and on the 4th pass it made a full pull.

Car ran 12.63 @ 108.41 mph with a 1.78 60 ft time


So we are at the limits of the stock fuel system and new one will be installed, still need to adjust timing and carb jetting and secondary opening rate and still have a little traction issue still, needs 90/10 struts up front and air bag in rear but car looks a lot better off the line.

should be able to hit high 11's with some more tuning and everything right, otherwise even on a bad day at the track once everything is worked out it should still be a solid low 12 car soon.

Not bad for a 900 dollar budget built engine so far. Using nothing fancy.

Enjoy.

 

Sweet!!!

 

Damn well done, great father and son project.

 

Man that's dang fast especially for what u got in it! Reminds me of drag racing back in the day with my dad. Good times your son will never forget.

 

Put a GOOD converter in it and a decent set of gears and you'de go a decent bit faster. That's flying for what you've done.

 

Good Job!

 

Thanks all for the kind words.


Before the budget built 355 sbc, I built a 305 sbc cheaper yet, around the 250 dollar mark. that got my son to 15.2 @ 93 mph.

Took a stock 305 tore it down and inspected it, honed and cleaned it and put it back together with factory original 1985 bearings and rings that I took out of it, took the 305 heads apart did a slight bowl port and put them back together with a set of z28 springs, slide in a 204/214@ .050" cam and used a eddy performer intake with 600 holley, shorty headers and a 10" jegs converter and 2.73 gears.

First pass down the track was 15.80 @ 87 mph, timing was cranked up to 42 degree total for best mph, then jetting, so between timing and jetting the car finally ran 15.2 @ 93 mph in it's 3rd outing. Son had fun.

 

Lots of fun per dollar there between you and your son Good for you!
Similar to what I did for my daughter and her car (in sig).

 

Well done.
Put some collector extensions on there and recover some of the lost low speed torque. You may be surprised.
Enjoy the time with your son.

 

That is the plan, son is earning his money from work and we will get some more parts as he earns his cash, some of the things on the list for improvements to get to the 11's is,

- header extension 18" long,
-rear right air bag for coil,
-90/10 struts up front,
-sub frame connectors,
-Edyy rpm air gap- should be worth about 20 more hp/tq over the Procrap intake
-adjust total timing for best mph
-adjust jetting for best mph
-adjust opening rate of secondary's for best mph
-change out water pump to a lower hp useage unit (weiand I think is the one)
-some kind of cold air intake
- msd box digital 6al need a rev limiter and son wants a bigger tach so he can see his shift points better
- adjust lower control arms for best 60 ft
- torque arm adjustable bracket- new crossmember- car is cleaner off the line
then stock suspension but still needs a lot of work and this might help.
-play with shift points for best mph at given track points
-play with launch technique some more
- play with slick air pressure best pass was with 10psi
-new fuel pump something with 3/8" inlet and outlet, something more then 110gph, new fuel lines from pump to carb.
- pull fuel tank upgrade fuel lines, inspect tank


No order for which this is posted, buy what he can when he can, get done what we can for next to free, been wanting to do the carb and timing tuning but car just couldn't make clean passes to note the differences, when the car was running in the 15's it didn't make enough power to mess with launch- they was all the same, so 2 degree timing bump you could see .7 mph increase, another 2 degrees was worth another .7 mph bump and so forth, so it made tuning easy, but now the car
really monkey's around on launch we need to get it cleaned up to be consistent to see the small changes in the right or wrong direction.

Feel free to add to my list of things to help to get into the 11's.

 

Any or all of the above will certainly be a move forward. A lot of what you're intending to do: rear right air bag for coil, sub frame connectors, some kind of cold air intake, adjust lower control arms for best 60 ft, play with slick air pressure best pass was with 10psi (my best pass was alos a t 10 psi) are all things that I've worked on or added over the years. The difference with mine is not not going so far as to turn it into a dedicated drag car. Too may crusing miles to log so I'll compromise the racing performance somewhat.
You may want to consider a wide band O2 sensor. It'll make you're track tuning much easier.
Of course there's always the weight reduction approach to things too.

I will say that there a whole lot of people here that have loads of experience making these cars fast at the dragstrip. Stock suspension types right to all out back halfed full out race cars. And all that's in between.
Good luck.