hi guys :

I'm confused putting back my TPi intake mainfold, i got everything what i need , a new set of mr gasket gaskets , RTV loctite sillicone , gasket sealer , torque wrench , a good set of torx bits , etc... but i'm confused with the procedure of putting everything back , i'm tired of searching , and everyone is saying different ways , rtv , gasket sealer , blah blah....

Of course , i have checked haynes , chiltons and GM service manual.

Any suggestions ? i'm blocked and confused , it's summer , and i can't wait to cruise a while with my IROC

Thanks and sorry about my bad english.

Suggestions ?

Here is my own guide :

1) Remove old gasket , protect the head holes , and lifter valley (to avoid particles gettin' in) , use wire brush and then clean the surface with solvent... let it dry (a vacuum cleaner would help you cleaning particles in the lifter valley). (done)

2) Question (holding the gasket in place) : Put gasket sealer on head and both sides of gasket ? , or put just RTV around water passages (first in the head , then on the upper part of gasket) ? , or should use both things ?

4) Discard cork gasket , and use a RTV on china walls , overlapping the gasket a bit.

5) Drop the intake , put a little qty. of RTV on intake bolts (to avoid oil leaks) , and torque it a bit by hand (using the snug torque sequence in chiltons) , until it's in place.

6) Let it sit about 1h.

7) Final torque the bolts in three steps (using this sequence) :

1- 20lbs/ft
2- 25lbs/ft
3- 30lbs/ft

http://www.chevythunder.com/intake_m...t_sequence.gif

 

I'm doing the exact same thing soon but you're ahead of me already with the intake drop. I have to clean my intake valley better since it's caked on with 21 yr old oily crud. From what I could remember once upon a 305...

2- I believe a smear of RTV on the block side would help aligning the intake manifold gasket in place to the bolt boles. Then apply a good smear to the intake manifold itself.

5- not sure why RTV is needed on the bolts, I use thread sealant to prevent leaks therefore Loctite is your friend. I think it wont affect final torque readings. Someone could shed some light on this simple matter.

7- What brand torque wrench are you using? I need to buy a quality one in the very near future.

 

I bought mine from summit , (summit brand) and cost me about 60$

IIRC :

http://summitracing.com/parts/SUM-G1055/

Thanks for the reply.

 

I've done just a bit of RTV around the ports without issue. You don't need to cover the intake gasket or anything else, just bead it around the port on the head. I've also used gasket sealant before. Either works, really. Matter of preference.

And yes, use a thread sealant, not RTV on the intake bolts.

For a quality Tq wrench, you can't go wrong with a Mac, Matco, Snap-on, Cornwell, etc. I personally use Matco. I feel the wrench itself only goes so far, the care of it, and quality of calibration put into it goes a long way.

 

Thanks! , gotcha i'll go with :
- Gasket sealant on the gasket and head.
- Thread sealant on 10/12 intake bolts (these two excluded are , the nearest to thermostat , and the opposite side equivalent)
- RTV on china walls , overlapping a bit the gasket.

What's about torque sequence ? , first i'll have to torque by hand (snug torque sequence) , and then use three steps 20/25/30 lbs/ft ?

I have a little fear , because my engine was leaking a lot!

Thanks again , you're great!

sorry about my english

 

Don't put gasket sealant on both the heads and the intake, just cover both sides of the gasket with it.

For torque sequence, start at the inside bolts, criss cross sides, and work outwards:


Generally, I do 3 steps of about 10, 20, then final at 30.

 

Thanks again.

Correct me if i'm wrong , but , this tightening sequence is for carb intakes , TPi intakes and Crossfire Injection have a different tightening sequence , this is for TPi :

http://www.chevythunder.com/intake_m...t_sequence.gif

Nope ?

 

I use the same torque sequence on TPI as I do with carb. There's no reason it would be different between intakes. It's still doing the exact same thing - fastening an intake to the heads with an equal force across the intake as to not get distorted or uneven. I've never had an issue with a TPI base being torqued in the manner of a carb intake.

 

The above sequence is correct for TPI intake manifolds.

I would do a test fitting of the gaskets. For example, with the cork gaskets on the front and rear china walls, and the head/intake gaskets in place, lay the intake down as square as possible, then aline (sp) the bolt holes. Check to see if there is a gap between the intake and the cork gaskets. If there is a gap, then use the cork gaskets along with silicone sealant when you do the final application. The cork gaskets are taking up the space that they should, so use them. I do everytime!

If the cork gaskets do not allow the intake to sit firmly on the heads, then do NOT use the cork gaskets. If you do in this case, then you might squeeze them out at a later date.

I never use locktite, I dont know where you would use locktite, never heard of its use when applying an intake manifold.

I place a little bit of gasket cement on the thin rib that separates the intake ports on the heads and on the bottom side of the gasket that matches. Let it dry for 10 minutes.
Then I place a smear of silicone sealant around all water ports on the heads. Now that you have waited 10 minutes above, place the intake gasket in place on both sides. Using or not using the cork gaskets, use alot of silicone sealant on the china walls. Lower the intake into place, straight down. Avoid moving it around alot after you dropped it into place. Line up the maniflod bolts holes. Look down the intake post if you can to verify that the intake gaskets are in place. Then bolt down the intake. 20 lb-lbf, then 35 ft-lbf is what I use.

And just for the heck of it, I use silicone sealant on the intake bolts. Most likely, medium thread sealant would be very good.

 

Stekman , IrocTheZ28 and doc , thanks!

doc: loctite have various products for the job , pst sealant or medium thread locker , those may work for the bolts:
http://www.summitracing.com/parts/LCT-37477/
http://www.summitracing.com/parts/LCT-37615/

The intake fit good with the heads and the block , i'll avoid the china wall gasket , and i'll use RTV instead this.

Finally i'll seal the gaskets with gasket sealer , instead of using RTV on water ports , exactly i had this :

http://www.summitracing.com/parts/LCT-39158/

Thanks again!

Sorry about my poor english...

 

Your first link is what I would use on the bolt threads.

The last link is what I would use on the thin rib which separates the air intake passages. This stuff would be a gasket cement or something similar. Do not use RTV here.

I use silicone sealant (this is what you are calling RTV), just a smear with the finget tip, around the water passages. THIS IS A MUST! Do not use cement in this area. And its just a smear.

 

hi doc :

This is what confuses me , i wondered using RTV around water ports , some people do that , and some books say that , but , theorically the Gasket Sealer (cement or whatever) , seals/glue like using the silicone , and is hot water/oil/fuel resistant , i'm wrong ? , this is what make me crazy , same thing , various procedures.

Check that :

http://www.chevyhiperformance.com/ho.../photo_11.html

Thanks , cheers!

 

BUMP

 

At least you spell good enough for me to understand and give advice!

Any pics of the intake job my friend?

Always good to see everyone chime in on the basic but deceptive technical stuff here.

 

heheheh , maybe i'll do the job this weekend , block and heads are clean now , ready to go .... but i'm looking for a tool to clean the intake ports on the mainfold , something like a long WC brush , here , where i live , it's really hard to get good tools , chemicals , or whatever.

Finally , i'll use RTV on the water ports , because when i pulled off the intake , was RTV on water ports.
Probably , using only sealer , would be insufficient.

Thanks.

 

Some tips from a guy who had to do it twice because he effed up: The instructions call for a 3/16" bead of RTV on the tops of the china walls. BS...you need to gob it on there, like 3/8 or bigger bead. I also held the gaskets in place with a small dab of super glue in a non critical spot, clean a spot of the iron with alcohol and a rag so the super glue sticks good.

 

Sorry I did not get back to you sooner. If it says that its resistance to hot water then it should be ok to use it around the water ports. I have always used the black silicone sealant around the water ports (Remember just a smear here) and on the front and rear china walls. Also, make sure that the cyl head and the top of the china walls are very clean and dry.

BTW: the black silicone also states that it is safe against O2 sensors.