I have to install a new intake manifold gasket prompt so i ordered one from racing beat. They wanted 400 dollars for a gasket kit at lordco and wouldnt sell me the intake manifold gasket itself.

First of all, how do you install one of these. Hopefully it will just peel off, if not il just scrape it easy with a puddy knife or exacto blade, after softening it with some gasket remover. I heard you put the shiny smooth side towards the block, rough side towards the intake. How do you keep the o rings in there? With P-gelly? Would that work good? What do you torque the intake manifold bolts back to? Any special way to remove the bolts so that the intake doesnt warp?

Second of all, i heard that porting these manifolds makes a large inprovement. When i say porting i mean cutting little slits about 1/4" apart with a die grinder, making sure there isnt any shavings in there, and go as far as possible in from the exit side of the runners. Does that sound correct? The intake will prolly see a turbo soon so i thought i might as well do this now so when i install the turbo, the fuel doesnt stick. Good, bad idea?

 

Use hylomar instead of *** lube for the o-rings. Don't port the intake mani. Unless you know what you are doing, you make the flow worse. Gasket has no up or downside, I make my own so I don't have to order them or drive down to BD to pick one up.

Torque is in the FSM, if you can't find in the section you are working in, then look in the spec section. At the end there is a list of bolt sizes, grades and torque settings for each.

 

No.

Nuff said.

 

Torque should be about 15-20 ft lb on the intake bolts I think. It may be less than that, but I don't think so.

 

14-19ftlbs tighten them all a little at a time and not all at once

 

i used some gasket remover, let it set for several hours while i ran to town, then used a plastic scaper to get the muck off, without marring the sealing surface.

 

Thanks. Wasnt there someone on this forum just lately who was talking about how to do the porting? Maybe not.

 

I ported mine, I port matched the primary ports on the intake manifold to the center iron. I did cut the slits, and I think they did something, but I can't tell if it's the slits, the port matching, removing of the shutter valve, or the lack of airpump. After all of this, I noticed a HUGE improvement in top end power, and more low-mid range torque. I think something I did kind of exacerbated my fuel milage problem, though I think it's just that my carb is old and needs a rebuild.

Here's some pics...

Before


After


Top view

 

Porting the primaries all the way is a big no no. You need to leave a lip there to help prevent reversion and having a runner turn and expand at the same time kills velocity.

 

how exactly did you do the cuts in the intake? how far did you measure down, and how did you get in there with a air tool?

 

I did those cuts with a dremel and a cut off wheel, which is why the primaries are not grooved, because the cut off wheel was too big, lol. As for measuring, I tried to just make them regular, I couldn't remember reading anything about a specific distance between grooves. I only grooved on the outside of the bends, that I could reach.

As for the ported primaries, oh well, live and learn. I just did what my inner 2-stroke told me to do, I used to hot rod small 2 stroke engines, and eliminating steps like that got me good results there. The car runs fine, and is faster, so if that porting actually did more hurt than help, I'll look for a used manifold on ebay when I look for a carb to rebuild, and just groove/remove the shutter valve only, and see where that gets me.

 

Awsome, im going to do the porting, as for the dremel tool, where can i get the one that i need? Btw, what size 1" 2" 3"?

 

smallest cut off wheel you can get, the smaller the better. It really helps to have a steady hand. As for the porting, I probably wouldn't do it. I don't know if it helped me at all. My car is faster now, but it could be from a combination of all the other things, and could be faster if I hadn't done that in the first place... If REVHED is correct.

I don't know if this effects emissions at all. Because there is no emissions testing where I live, I removed EVERYTHING when I did this, rats nest, airpump, acv valve, cats, etc. I removed the shutter valve because it was broken, I think if you've devacced your engine the valve won't work anyway (It goes through one of the vacuum solenoids you remove I think.) I filled in all of the holes in the manifold with steel putty, smoothed it out with my finger, then sanded it down with a sanding drum on the dremel. When I did the porting on the primaries, I used a carbide cutting bit in a drill press, and held the manifold in my hands, achiving the cut I wanted by moving the manifold around (With a death grip, it likes to jump around.) removing large amounts of metal like I did with a dremel would be expensive and time consuming.

 

yeah unless you had a aluminum bit, i know you can remove a **** load of metal with a alum bit, ive had to do it before. I used to be a machinists right hand man. Yeah il look around to find a dremel bit. As for the porting, how long have you run the car now with it ported like that? Maybe il just round it out and smooth it with some sand paper. Thanks. Once i get this **** done, or maybe you, should write up a how to. Btw, ive already did all that stuff with the shutter valve. i noticed a gain too when i removed it.

 

Is there anyone else who can verify that porting like Box Man did with the runners expanded a bad thing?

 

way back when i ported my rx3 manifold i also had a shop make a 1" thick spacer between mani and carb. out of delrin. longer intake tract, got more torque. on my daily drive I noticed less throttle was needed to maintain same speed on a long straightaway by my house.

 

so your saying a spacer would help, so when the spacer was made, what all was done to it? Just matched to a intake mani gasket? i have access to a machine lathe and i would make one if i had an idea how to, not right now, but later on when i source some derlin

 

same size holes as intake gasket. 4 round holes for air/fuel to go down, 4 small holes for studs. needed longer studs too, think i got them from summit.

 

I'll do my writeup soon, whenever I de-grease my engine (tomorrow hopefully)
I've been driving the car for about 375 miles now, instead of my gas milage being 16.3MPG, it's now 16.9MPG (Makes me miss my CRX). My carb has suddenly gotten worse in the past few days, the idle is a little more rough, and it backfires. This isn't much of a problem though, since the backfiring keeps the ******* talking on the phone and tailgating me alert. I got on it in second gear the other day, and at WOT climbing from 3k RPM it was kind of jerking it's self along, like it was getting uneven fuel flow at the jets (Again with the small 2 stroke thinking). When I get the new manifold I'll do some measuring to see the area of the primary ports at the engine side and the carb side to see how they differ, because they sure looked smaller at the engine side than the carb side.

 

Im just going to look around and see if i can find any local Derlin, if not then il have to order some. All in time to come, everything i think of i write down so when i actually start making some good money out of school here i can build a good widebody turbo 12a that pushes 300 at the rear wheels. You have to build yourself up tho small. Do what you can do with the money ahand, know what i mean?

Yeah i knew i was going to have to get longer studs, im sure i wont have to go to summit to get the studs tho. Just find the thread-pitch, daimeter, and correct length and you can get them at any machine shop, if not they can order you a box. Either way. Not bitchin or anything. So match the intake ports and the bolt holes, easy enough.

Sounds good as for the write up. Smaller at the exit size eh, so there a little lip right before it goes into the engine. When you cut out the ports they matched the engine correct? If so i still dont see whats the big deal about the whole thing. We still havent heard one thing about the whole idea becides from one person. But let me ask you this, why would they make them with a lip from the factory, they would atleast nearly match the ports. there has to be a reason. What i think would be a good idea is to convex the bump and smooth it out really good after shaving a small amount out, then give it the ridges. That way the air flow isnt as interupted before entering the engine. Turbulant but fast* You dont want the fuel sticking on the inside of that lip. Fuel droplets are a very bad thing. If the fuel did ball up, it would create shitting hi-end torque and gasmilage. From the factory they might have not rounded it out because it would have took too much time to port it, time is money and 2 hours of porting would have cost a large drop in profits. Remember these cars were a touring car, not a race car.

 

Btw, low gas milage makes me miss my first gen crx. POOR LIL BEASTIE II.

 

Hahaha, I thought you were the guy from Red Pepper Racing, small world.

I'll try what you said, my porting still has a bump there, but it's round instead of a right angle, so there is still kind of a bump there. I'll still get another manifold and compare the two.

 

So you basically did what i said, good plan, yeah im going to shorten the lip aswell next week. Did you machine between the secondary ports?

Hahah no kidding its a small world, i kinda had a feeling that you were from the site too. What was your screen name?

 

Sort of, It was kind of a conservative port match that I did on the primaries. When I do headers for nitro RC cars, I match the flange to the exhaust port, and keep the transition as flat as possible, but the transition on the primaries is kind of rounded.

Here's a crappy MS Paint rendition of what I did...


I did port match the secondaries too, the intake side was a little under a millimeter smaller than the engine side.

My RPR screen name is EDGE540, I haven't posted in a while, and I only had like, 350 posts, lol.

 

You just killed all of your lowend torque and increased reversion/overlap.