86firebirdta

I have a 86 305 tpi trans am 700r4 with a 9 bolt borg i ported out the stock plenum and runners have hooker 2055 21/2 to magnaflow 1.6 roller tipped rockers 19lb accel injectors full ignition tune up im jus startin into lookin into cams not knowin too much about them but im not lookin to go with anything too radical keeping the stock heads for now and i kno they cant handle much but would it be worth getting either a stock lt1 cam or l98 cam and putting it in im really lookin for the least amount of work possible for now with low budget im jus wondering if im goin on the right track

vetteoz

iTrader: (13)

Does your engine have roller cam /lifters?
Late L98's and all LT1's have roller cams

86firebirdta

have no idea but if not i can change to roller lifter correct?

watajob

iTrader: (29)

Yes but will be big bucks as you'll need retro fit lifters as I believe an 86 is a 1 pc. RMS but shallow lifter bores and no bosses cast in for the retainer.

F-Body Demon

iTrader: (1)

86 should have a roller cam, easy way to tell is if the valve covers have center bolts rather than perimeter bolts. Somebody stop me if im wrong but my understanding is that when GM changed to the 1pc roller they also changed to center bolt.

I would try and steer you away from getting a small cam just to fit the limits of the heads because you REALLY need to change the valve springs when you install a new cam when the differance is that severe and especially when the springs in the car now are the ones GM put in there 22 years ago.

Rolling Thunder

86s didnt have roller cams. Motors 86+ did but a car built for the 86 model year would have been built in 85 and from stuff produced in 85 and earlier which includes the earlier non roller motor. Some times a car built in the later production of that year may have gotten some of the newer stuff but in this case i doubt it.

86firebirdta

I have perimeter bolt on the covers but these lifters would not work http://www.summitracing.com/parts/CCA-850-16/

ploegi

Nope. You would need some form of retrofit kit, and I am not sure if your block even has the castings for the mounting points.

86firebirdta

well wat would be a good mild cam for my car

ploegi

Probably anything would be an improvement..... But, basically, look around summit for a cam/lifters (hydraulic, non-roller) with a power range with max RPM around 5000-5500, as that is about all the TPI will support in stock form.

What does your tach say your engine redlines at?

86firebirdta

its at 5500 but i guess with that cam im pretty close to my limit as it is so the only other one that would fit my heads that is bigger is the crane cam 104111 so theres not much more of an option than gettin new heads

Rolling Thunder

Personally, If i were you the cam I like for hydrolic flat tappet motors is the comp cams ex256h. Its designed to operate from just off idle to a little over 5 k RPMs. Its got great low end torque and street ability while offering good high end performance. It would make a great street cam thats even tailored to work with TPI fuel injection.

86firebirdta

if my goal was to get 300 hp out of this thing wat would be a good outline for it not tryin to do nothin crazy jus need the ideas and where to start

flaming-ford

iTrader: (7)

well i would get something like the following.

http://www.summitracing.com/parts/SUM-K1103/

http://www.summitracing.com/parts/CCA-CL12-234-2/

http://www.summitracing.com/parts/LUN-60101LK/

basically you want a camshaft with a split pattern (slightly higher on the exhaust side in terms of lift and duration as well as a 112 lsa or higher in order to be more efi friendly).

btw you never replace a flat tappet camshaft without replacing the lifters. also make sure when you brake in the new camshaft that you use zinc additivie or rotella oil while follwing your camshaft brake in procedure.

also you realy should replace your valve springs with something new and able to take up to .500 lift or so.... you must remember the factory camshaft is a ton smaller with much slower ramp rates, so replace them just so you're sure not to experience valve float.

Rolling Thunder

300 hp although not unreasonable will take some work. Primarily the first thing that comes to mind is headers and exhaust and the cam. With those 2 things i think you could be in the high 200s like 280 or so. Fortunately for u the TPI intake was designed aroung the 305 so you wont see much improvement by upgrading it. The heads although not the best i think would support your goals as well.

86firebirdta

well i have a full exhaust hooker 2055 2 1/2" pipe with a single cut out and a magnaflow muffler.... with changing the springs my heads will be able to handle over .500 lift??? and with those cams the tune wouldn be too hard would it?

Rolling Thunder

Well i dont know how that motor will like the 2.5 intermidiate pipe and the cut out has mixed results as to improve or decrease performance depending on how its set up ect. As far as the max lift is concerned im not sure what the max lift without machining really is (although conciser if you have to use a dual spring that will require machining regardless) course there's more to it than that. Then theres coil bind issue to contend with. Heck even the rockers can cause issues if they dont allow for enough travel. Plus you have to conciser there valve to piston clearances as well. Then theres the issue of once you get a cam thats that big you have to start considering machining the heads for screw in studs as the pressed in ones can be pulled out by heavy springs. That being said It really depends on what cam you get but regardless of what you chose you should always check the clearances. Some cams are more likely to have troubles than others but still its a good idea to check especially considering its not to hard to do (except for piston clearance its easy but you have to pull the head). However the piston clearance i wouldn't be worried about till you get into the high .4s and .5 and over ide definitely be concerned. So to answer your question there's no way to really know without measuring but i wouldn't expect it to just be fine for over .5 lift with just a spring change. As far as tuning is concerned thats really a matter of opinion. Because its MAF and you not building a real radical set up its about as easy as it going to get in my opinion. It would probably even run pretty well on the factory tune (although a tune is advised regardless).

86firebirdta

So If I Was To Junk My Heads And Look For A Pair Of l98 I Would Be Sittin Better Or Jus Keep The Stock Heads And Get The Machine Work Done To Them.

Rolling Thunder

Not neccessarily as the L98s may have all the same problems. At that rate it with all the machine work that would need to be done to end up with an inferior head it starts too look tempting to get aftermarket heads that come all set and will perform better. Course the other option is keep the lift under line .48-.49 because although ive never flowed those heads before i doubt they flow enough to warrant over .5 lift. Its one of those things factory heads will kinda hit a brick wall when it comes to flow rate of the heads. What i mean is youll see a large flow increase when the valves open from .2 to .3 or .3 to .4 but then it may flow 200 at .5 and 205 at .6 and at that rate is all the work machine work worth it to gain 5 cfms? Granted thats not really the whole story there's the area under the curve to contend with and a balance of duration and ramp rates needed to even obtain a certant lift but thats the general jest of what im trying to say. If you had a good performing head that flow increases substantially up to .6 in lift then yea go for it but otherwise its not really worth it. Concidering you dont really have a radical build up pic a tame cam to match that will hopefully (still have to check) not require any machine work. To me that would be your best bet.

d4nk

iTrader: (2)

I attempted this a few years back on my original '86 305. It was a flat tappet as well. Went with the trickflow 56cc cylinder heads (http://www.summitracing.com/parts/TFS-30300002/) and the lunati voodoo 60101 (http://www.summitracing.com/parts/LUN-60101/). It ran decently but still wasnt stout enough for what I was looking for, so I went with the 4" bore mod.

A fellow member in our local club ran the lunati 60101 cam in a set of stock L98 heads and started poping rocker studs out. So even though it is relatively low lift, you still have to watch it or those studs will start working their way loose. Only other option would be to drill and tap them for screw in studs, or go aftermarket. I think the general rule of thumb is to keep the lift below .450 with the stock'ers.

86firebirdta

thanks for all the good info i really appreciate it.....
http://www.summitracing.com/parts/SUM-1787/
would this cam be the way to with the 1.6 rockers

d4nk

iTrader: (2)

With 1.6 rockers and that cam it is going to put you up to .455 lift. You might be able to get away with it running the stock heads but you better be carefull not to take the rev's up too high. Personally I would get the heads drilled and tap'd for screw in studs, or at the very least get them pinned. Then upgrade the valve springs and then you can put a beefier cam in.

86firebirdta

so that cam will work with my set up?
i kno the lifters i need but wat kinda springs would i need im kinda lost on those and it looks like a tricky job in order to change the spring.

Rolling Thunder

Personally i think you would be ok with that cam and a 1.6 rocker arm set up. As far as springs are concerned you always want to go with springs that are recommended for use with that cam shaft so give summit a call and ask them what there recommendation is. Being that cam isnt too crazy i dont think the springs required for that cam would be tough enough to pull out the studs but only one way to find out for sure lol. As far as spring changeing goes it does kinda suck its not difficult just time consuming. However theres no way around it as with any cam change the springs should be replaced with new ones.

ploegi

And changing the springs also is an excellent time to put new valve seals on. After all, you are RIGHT THERE, and doing the rest of the work anyway.

88gta_hiflyer

iTrader: (1)

Your 86 has a flat tappet cam so and LT1 or L98 wont work but there are lots of good choices for flat tappet and they are about one fourth of the price. I am really impressed with Lunati's Voodoo line. You are at somewhat of an advantage without center bolt valve covers as far as rockers go. I would step up to at least a 1.6 roller rocker.

86firebirdta

i have 1.6 rockers already right now im jus wondering which are the right springs and seals for it

d4nk

iTrader: (2)

the valve springs recommended for that cam are trickflow's part #TFS-15104
http://www.summitracing.com/parts/TFS-15104/ You might want to call summit and double check with them to verify it.

I am not sure as to what valve seals you need because I dont know the specs on your heads or at least the casting #'s.