One of my friends has an 87 TA. The motor that's in in is out of a corvette. To be completly honest the only things that I know about the motor are that it's not an LT1 or an LS1 but it's not carbed and it has fuel injection. What are some ways to tell what kind of cam I need to buy. Also, how do I know what's the safest lift to run and still be okay? By the kind of cam, I mean do I need hydro, hydro roller, solid....? Could I just put a comp XE 268 in it with a new set of lifters and a pete jackson gear drive and call it good? I'm pretty sure it's a 305.
Also, how the hell do I adjust the idle on this thing? Once we put the cam in, I'm gonna wanna turn it down so it'll lope more. But, I have no clue how to adjust the damn thing! Is the valve lash adjustment the same as it was for the XE 268 we put in my 68?
Thanks alot,
Donnie

 

I think the XE 268 is a little big for a fuel injected 305. I think that even an XE 262 would be barely streetable. You probably want to go with the XE 256 since it's fuel injected. As for the lifters, they are hydrualic.

 

if its from a vette its not a 305, (ok unless its from a 1980 california car)

Best way to check is to see if the heads are aluminum, they should be nice and silver colored. If your not sure use a magnet.

If its a t/a its a tuned port engine. If its a late 80's vette engine it has a roller block. You cant just turn down the idle to make it lope, the ecm will compensate. Besides thats a stupid idea, you tune an engine to have as little lope as possible. Yeah it'll sound cool, but it'll have terrible off idle response.

What you need to do is find out exactly what kind of engine it as, get the numbers off the fron t of the block.

Unless your friend put the engine in himself or has some proof, its probably a 305 fbody engine.

 

This sounds like the usual monkey-spank about "Vette" motors; that usually means "looks like a Vette motor" (typical person who's unfamiliar with TPI); "was in a Vette for a while" (like the 70s Impala 2-barrel motor somebody is passing off as a "Vette" motor because it had been in a 80s Vette); "paid alot for it because somebody invoked the magic V word"; "it's almost the same as a Vette motor, it's even a 350"; etc. Nobody here cares whether it's a Vette motor or not, this is a F car BBS. And even if it is, it's a bunch of parts; no magic romantic essence emanated from the fiberglass and jumped into the castings that's going to make members of the opposite sex find your car irresistible. Why this sort of thing makes any difference to anyone is beyond me; it's a bit like putting a wing on the rear of a front-wheel-drive car. Poser BS!!!!

Most likely the 87 T/A motor is not a Vette motor at all, it's a T/A has TPI. This would be in the "looks like a Vette" category. Not that it really makes any difference.

Best thing to do would be to look at the block and get a casting number, and figure out what the CID really is and whether it's a roller block or not. This will significantly impact cam choice.

In no case would a XE268 be the right thing. That's a great carb cam but a horrible mismatch for TPI. It would slow the car down probably half a second, even if you could get it to run anywhere near right at all.

 

Damn did that motor suck. I sware that had to be the worst Vette ever made.

 

Guys,
To be honest, all that I know about the motor is that it has iron heads and that it's out of a vette. It's TPI. What are some easier ways to tell if it's a 305 or a 350 and if I need a roller cam?
Thanks alot,
Donnie

 

No Vette TPI motors ever came with iron heads. So, even if the motor has happened to have been surrounded by a Vette body for part of its life, it's not a "Vette" TPI motor. Forget the "Vette" crap, don't even mention the word again, and let's get down to reality.

Look at the top of the bell housing flange right behind the pass side head. There will be a 6, 7, or 8 digit number cast into the block. That's the block casting number. Look it up at www.mortec.com and find out what size the engine probably is, and whether it might have come with a roller cam. Then pop a valve cover and look for a similar sort of number on the top surface between 2 of the rockers. Look it up and find out what heads are on it. Hopefully both heads are the same casting, but you'll have to pull both vallve covers to find that out. If the block comes up as one that might have a roller cam, you may want to pull the intake and see if it has the factory's Frankenstein roller thing in it. There's no way to know if it's there (even if the block shows to be one that has roller provisions), it may be a truck block that wasn't roller equipped from the factory even though it could have been had they wanted to outfit truck motors that way, or somebody could easily have slid a flat tappet cam off in it. Happens all the time.

Whatever you have is not what you think you have, or what you first told us you have. It's something else. So there's no way any of us can tell you any more about it without you looking at and posting those numbers.

 

Guys,
LOL...okay I won't even say it's a vette motor any more! If it was my car I guarantee you that I'de know every little detail about it but it's a friend of mine's car and I was just going based on what her and her dad told me. Like I said I know that it's TPI and I know what aluminum heads are and they AREN'T aluminum. I know exactly where the casting number is but it's practically impossible to see because of the firewall! I'll try and get the number though because it's pretty much vital in a cam swap obviously.
Thanks a million,
Donnie

 

That's pure ! Have you ever ran a xe268 in a TPI car? I have, and it's still in there. Altough it takes some chip burnning to get it to run right, that's what it takes when you start modding.

 

Alright........it's a 305. It has a hydraulic cam and it's flat tappet. First off, can I just use the stock lifters with the new cam? What is a good cam to run in the motor? I want a nice lope at idle such as an XE268 or even a XE274 at about 700 or so RPM idle in drive but not extremely radical.....we're probably going to run a pete jackson gear drive(the quiet one) if that makes any difference?
The motor has stock heads & valves, it's TPI and it'll have flows, and a CAI. It's the stock tranny and rear-end gears whatever the ratio's are?

Also, in comparison to the cam swap on the 350 in my 68 camaro....how tough will it be with all of the smog crap and fuel injection on her motor? What all else is required if anything? Is the valve lash set the same way? How do I turn the idle down or is that even possible?

What ever cam we end up getting, I don't want to have to screw with the computer at all....I just threw that in because of the one post saying that in order to run an XE268 I'll need to reprogram the computer.

Last thing, the motor will need to pass smog.
Thanks a million,
Donnie

 

First off, if you're NOT doing anything but the cam, mistake!! 268 is way TOO big for a stock 305. One mod demands another, in the performance world. Always has always will. You can't put used lifters on a new cam, excuse me, you can BUT the cam will probably go flat before you get broke in. Can't use the stock valve springs on the xe cams either. If you're leaving every thing else stock, just use a stock replacement type cam.

 

I didn't mean that I wanted a 268, I meant that I want the lope that a 268 gives in a 350 but the equivalent in a 305....what's the most lift that I can have and still run the stock valve springs?
Thanks again,
Donnie

 

You are barking up the wrong tree. Performance is not about having a cam with a "lope." Really.

You choose a cam according to the other parts in your engine and the ratio of rear gears you have.

This "lopey idle" business is just goofy. Taking a stock 305 and putting a high lift/long duration cam in it will make it run poorly. Probably make it a slower car!

A stock 305 should be limited to something like a Comp XE 250, certainly nothing bigger.

 

I know that a lopey idle doesn't make a car any faster. But a I just a little lope at idle because it sounds good and eventually the motor will be built alot more....I don't want a crazy sound like it's going to die at idle but I definestly want people to know it's there.
Could I just run an XE 256 or XE 262 with a new set of lifters or is that too much cam? I honestly know NOTHING about what's too much for a small cube small block.
Thanks again,
Donnie

 

OK, you are admitting that you "know NOTHING" about choosing a cam for your basically stock 305.

The folks trying to help you here really DO know what they speak of AND they are just trying to help YOU. If they didn't care they wouldn't even answer your question, would they?

An XE 262 can only go in a very well built 305. That is just the way it is. (A 268 is not even to be considered!) You would also need at least 3.42 or, better yet, 3.73 rear gears because that cam moves your power band higher in the rpm range and you would lose too much of your lower rpm grunt. A stock engine EXACTLY like yours would probably beat the one with the 262 cam because it is such a horrible mismatch. And in your case, you have a TPI engine so you must stick to something like 3.42s because the TPI engines don't rev much past 4500 rpm. That is just a physical limit of the engine because of the length of the TPI runners.

Furthermore, when you add more air into the combustion chamber--which is EXACTLY what a high performance cam DOES--you also must provide for its removal. That requires headers because stock exhaust manifolds and pipes on 305s are the definition of restriction. They are terrible!!!

Consider this, the cam you have now probably has the following lift; .350 on the intake and .385 on the exhaust. That is TINY compared to even an XE 256, which has .447 intake and .454 exhaust. The 262 and 268 cams are larger yet. The 256 is about the absolute limit that the stock springs can cope with before they bind. Now do you understand why no one is telling you what you have in mind is good?

You are simply demanding too much lift in the cam, and you don't even have a way of getting rid of the exhaust it will create.

The thing that causes a "lopey" idle is actually the intake and exhaust valves being open at the same time. Exhaust gasses are being fed back through the valve and into the combustion chamber, contaminating the fresh fuel/air mix. This is because to accomodate those higher lift numbers the cam lobe must keep the valve open longer. That is called duration and too much forces the valve openings to "overlap" (be open at the same time for part of their cycle) and that makes the engine run rough. THAT IS ALL IT IS!!! IT ISN'T A SIGN OF A FAST CAR UNLESS ALL THE OTHER PIECES ARE THERE, TOO!!!

The only reason the engine eventually smooths out is because at higher rpms (well above idle) the exhaust picks up enough velocity to overcome the "urge" to flow backwards into the chamber.

So take everyones' advice and go for something like an XE 250, which will work pretty well with a stock TPI 305--at least in comparison with the other ones.

But STILL you should put headers and a 3" exhaust on before you even consider a cam. A good exhaust will make that stock 305 go a fair bit quicker, while a cam will just confuse it

 

Yeah, but you are using the XE268 in a well built 355 and RB83L69 was talking about using it in a stock 305. Those 45 cubes and other parts make all the difference in the world! Plus you have 4.10 gears. For all we know this other fellow might have 2.73s.

 

Read my other post. I didn't recomend a 268 for him. I mearly stated that a xe268 will work in a tpi car, if other mods and tuned. It all depends what else has been done.

 

Think you should leave this car alone. It's not your car
and you know s**t about cams, motor or Vettes.

Let the owners choose a cam for their car. You're only going
to F**K it up on 'em.

There is a lot more to it that picking the Sexy est cam of the year
out of the Summit catalog and bolting it in.

Maybe your friend and her dad should put in a "VETTE Cam"

Seriously leave it alone.

 

If he unplugs a spark plug wire he will get a nice lopey idle
I think I will go get a VETTE moter for my car.

 

Let's all jump on 68Camaro!!!!! come on!!!!

 

Everyone,
Thanks! Like I said, I honestly had no clue that a .470ish lift cam was THAT big in a 305.
And I know that a lopey idle means nothing in the way of speed but any person in their right mind would agree that it sounds awesome right?

Oh, 88 F-bird or whatever....you know **** about me....I know plenty about cams! I know nothing about 305's or small cube small blocks in general for that matter. But, I'm tryin' to learn so gimme a little credit! Yeah, I want the lopey idle but at the same time I want better performance too, that's all. I'm just tryin to figure out my options and which is the best choice!
Thanks again(especially Sitting Bull),
Donnie

 

Plain and simple, you want a 262 for the 305. I think most anyone in here would agree its the best cam for a mild-stock 305 engine.

 

The thing about a cam that makes it "lope" is opening the intake valve real early. This makes a certain amount of the cylinder's remaining exhaust gas to get "barfed" back into the intake, which then poisons the next cylinder's charge of air/fuel mixture. You make a cam open the intake valve earlier in order to raise the peak torque RPM.

Now consider how TPI works. It consists of "tuned" (the T in TPI) runners. This means that no matter what the engine thinks its peak torque RPM is, the runners are stuck with being "tuned" to the frequency (RPM, number of intake pulses per minute) that is determined by their length. That particular RPM is about 3600. Nothing you can do to anything else will change that peak torque RPM, which occurs at a very specific point.

If you put a cam into a TPI engine that attempts to deliver peak torque at some other RPM besides 3600 and at the same time lowers the engine's volumetric efficiency at 3600 RPM, the car will go slower. Period. It's not like a carb setup, where you can slide as big a cam in as you want to, and as long as you can pour more fuel in, the RPM power band will follow the cam profile. With TPI, if you think in terms of choosing the cam to maximize the engine'e performance at 3600 RPM, instead of choosing a cam to raise the engine's peak performance RPM, you'll beat the guy that puts the big cam in his TPI.

Another issue is the computer control over the motor. A cam that "lopes" strongly affects the engine vacuum at idle and low RPMs, which is where the gears they use with TPI always keep the motor pinned. The computer is not tolerant of major changes to this part of its operation. THis is part of what people are working on when they burn "custom" chips.

A XE268 is a terrific cam, but is completely wrong for a stock TPI, especially in a 305, no matter who says their engine runs good with it. I would bet money that I could pick a cam that would make even a 350 TPI produce at least 25 more HP than it would with a XE 268H, and I guarantee it would be a smaller one than the XE268, and it wouldn't "lope" much at all.

My recommendation for your 305 is a Comp 12-402-4, which is a 260AH-14. It's specifically designed to work well with the properties of TPI. I would not go any larger than that until the engine had been upgraded in a couple of other key areas: a set of chassis-specific headers, a high-flow cat, a good cat-back exhaust, and a set of decent gears like about 3.42 (no higher - remember the RPM constraint), and a higher-stall torque converter. If those parts of the car are still stock, a too-big cam is a recipe for certain disappointment.

So what does your friend really want: a slow, gas-guzzling slug with poor driveability that lopes, or a car that goes faster?

 

How would a XE268 Cam idle in a 305 with a 600 Holley. (with headwork, 9.1:1 compression etc..)

 

Guys,
Would I be better off to go with an intake manifold at the same time? Header's will be on the car shortly after the cam's installed...If yeah on the intake, what's a good one to run?
Again, I don't know much about TPI intake's or much about Fuel injection in general.
Should I go with the XE256 or is that still pushing it?
Thanks again,
Donnie

 

i thought 85 and 1/2 of 86 production came with iron heads

 

for the 87 i would go with the comp cam 212/218 449 /456 112 lsa i just ordered it for my 86 peanut cammed 305 tpi . thats all you need and that cam is designed for your engine.

 

yes you are right, the 82,84,85, early 86's have the same iron heads, these were later converted to centerbolt and are the heads used on fbodies until 92.

 

SMOKEN- Thanks man. What else is done to your motor? Or just the cam? How much bigger than stock is that one? Also, is that a flat tappet cam?
Thanks again,
Donnie

 

ttt