Racod

For all those intake pros out there.

Is this a good deal?? I am interested in this for my L98

http://www.ebay.com/itm/TPI-INTAKE-POLISH-SERVICE-TUNED-PORT-SBC-HOT-STREET-ROD-L98-CORVETTE-CAMARO-/190940714815?pt=Automotive_Services&hash=item2c74f4173f&vxp=mtr

Thank you

tunedport85inject

Do you look for a "ported intake" or "just" for a polished intake.I've recently polished my 85 rims,and belive me bro...lot of work.Figure out that the 85 rims are a flat piece of aluminum,very simple to work on.Now look at that intake,take it apart,dismount it ,and start to work on that irregular surface,lots of manual work with sand paper just to flat down all that rough casting surfaces.When everything is smooth and fine ,you have to start with finishing using different grade of sand paper from 180-320-400-600-800-1000-1500-1800,then you start with the polishing cotton wheel and 3 different polishing compound to finishing the surface mirror like.Imagine to work around the runners...If i was you,i would cut the corner and buy it...(btw this is a polishing SERVICE not an item to buy,you'r paying for have polished your own intake)

cv67

Polishing work looks nice usually better to pay someone to do it.

-Stock runners cannot be ported
-Plenum, if you have aftermarket pieces or very heavily ported stock ones under it (+aftermarket runners) may act as a finishing touch but dont expect gains by the plenum itself)
-Base, sounds like maybe just the lip is taken out a little which doesnt really do much of anything. A real effective port job on a TPI base takes many many hours and will cost a whole lotta money. Id say your money spent here is for polishing than anything else.

Racod

Thanks. I am looking more for the porting. The polish would be a plus.

Any good vendors for this??

tunedport85inject

Look at this guy video on you tube.He makes good porting job ,specialized in TPI and LT1 intake.He offers his porting service and his works are very clean and ,he says cost effective.Find him on Facebook under High Flow Fuel Injection .

leesvet

Remember, to make "porting" truly effective, you must include the heads in the program....you CAN port match the stock head ports to the new intake. If you don't, the benefits end ..or never really begin because the head port is still a restriction. You at least have to gasket match the intake to head. Otherwise the much bigger intake ports will have head ports much much smaller thus screwing up the flow.

I polish aluminum and do some intake work when something comes around. I can tell you that its common to remove as much as 5mm of metal off of one side of an intake port to properly mate it to the gasket (template) that in turn should also be the guide for the head ports....

That's a BIG edge hanging in the breeze...to slow it down if the head is not matched to the intake.

tpi 421 vette

If you are looking to have your stock intake ported, I would seriously consider having Ron ( Cuisinartvette) do it. His work is awesome and is very reasonable in price.

junkie

Will there be any gain in doing intake/top end only porting with stock exhaust? Does adding headers with the porting help?

tunedport85inject

The entire system has to flow better than before,no bottle neck are admitted,if just one component restrict the system you fail.Best breathing from the top (TB-plenum),best flowing through runners and intake,obviously porting the heads (not only port matching/gasket matching),and free flowing down the exaust (long tube headers,no cats and big diameter exaust pipe (obviously in math relation to heads cc's engine displacement...).That said you can feel an improvement from a ported top end with just a good set of headers,relatively speaking

tunedport85inject

Here we go! buy a Centroid for just $ 500.000 and you'r in business

vetteoz

http://temp.corvetteforum.net/c4/vader86/minormods.html

junkie

Thank you

leesvet

If you're running the stock ex manifolds, and budget prevents you from doing the whole header/ cat-back system, you CAN bolt up LT ex manifolds to the SBC block and get a better flowing exhaust to support the better flowing intake. If you do some digging here, there are some pics of the TINY L98 exhaust manifolds that cover 1/4 of the exhaust port ! The stock L98 manifold is smaller than the port...BUT the LT manifold is slightly larger...AND its almost a clean fit to the stock down-pipe exhaust and it bolts up to the block. Cheapest way out. Porting is tricky. There is something to be gained in almost any system. The mass produced manifolds never match exactly and there is always a gasket edge hanging in the air stream somewhere...no matter WHOs name is on the pieces...
Whenever you clean up these mis-matched pieces you equalize the flow to all cylinders, get more flow and that translates to better throttle response and much improved revving even IF it does not yield more HP, but it usually DOES. I almost $hit a kitten after seeing how quick mine revved after exhaust work with a new top end. It was like....not now, RIGHT NOW !

Whatever you do will help,. but those exhaust manifolds are the single biggest restriction in the whole engine. The LT swap is a big step UP.

junkie

Would it have to be a corvette lt1 manifold. I found some F body ones and wondered if they would work.

cv67

Getting a converted LT1 intake would be a giant leap forward. Fuel rails on the Fbody are on the DS that can be changed, tiny differences not positive about.

Know that not every motor will benefit from intake porting.

Sometimes working something over that has ample supply already could lead to a step backwards in performance.

GREGGPENN

The general concensus (and fact of the matter) is the 350 L98 long-tube intake was designed for the 305 engine. It’s considered undersized for the 350…though I’m thinking it WAS used on a bigger displacement motor. The issue boils down to what rpm you want maximum torque – with that 10% (ish) bump in power (due to intake reversion inside the long-runner intake). Porting these intakes should not be pursued – as mentioned by Cuisinartvette in post #3. Ron is an experienced builder/porter and knows his stuff. The walls of the stock runner are too thin to attain meaningful porting. Porting the plenum is also virtually meaningless. The only stock piece where the value of porting can be seen is the base. Extrude honing of a stock base gets it similar to aftermarket Edelbrock, TPIS, and Accel long-tube bases. By contrast, you could use that money to buy the aftermarket base and have even more room to port.

With a bigger base, the addition of larger/shorter runners is mandatory. IOW, improving the base w/o changing runners is worthless. Upgrading the entire intake – to a large runner intake – is worth 5-10% in power gain. Considering the cost, many consider that upgrade also worthless.

The best bang-for-the buck upgrade is a modified LT1 intake (as Ron also suggested). With bumps in spending, you can consider Super Rams, Mini Rams, XT-Pro Flow, HSR, FIRST fuel injection, or carbed intakes. All of these options flow better than modified or improved longtube setups. That means you’ll get more horsepower from shorter-tubed intakes. Your torque many rise only slightly or not at all. By moving torque to higher rpms, you gain horsepower though. You also gain the ability to stay in a lower gear longer – which is a gain in mechanical torque (gearing). (You can also change gears and, likely, get another bump.)

On the exhaust side, ported manifolds, shorties, or long tube headers will increase performance. Expect a similar 10% gain from exhaust improvements…probably a bit more. Stock L98 converters and exhaust manifolds prove the biggest restriction – even more-so than the 305-designed intake. This could be considered debatable. However, the intake really shifts torque lower while the exhaust problem plain gets in the way.

Bottom line: Porting stock L98 intake stuff is worthless and should never be considered. Porting L98 manifolds is somewhat useful but isn’t worthwhile unless you can do it yourself. Buying exhaust manifolds is a better way to spend money. This forum has a wealth of threads asking how to gain more power. You can read thread-after-thread how to accomplish this. I recommend looking at what people have asked and the answers they’ve given. This forum is pretty darn good about jumping on bad/wrong answers. By the end of any thread, there’s a good chance you’ll find “the answer”.

Good luck with anything you try. And, btw, I don’t see anything wrong with going the bling-bling option if a polished intake is really what you’re after.

Sleazy Rider

I think you're missing a couple of zero's.

ch@0s

I think his Comma is broken.

Op here is my ported intake and aftermarket runners for comparison.

I also modded an HSR later to fit ude my hood.