Porosity (continuing saga with the 18984, 3.8) January 17, 2011, 07:32:15 AM Anyone every dealt with porosity?Can actually see coolant coming through the metal on the intake on what I'm going to call the riser pipe area on the front of the intake where the temp sensor is mounted. Takes about 3 hours for it to show with a pressure of 13-14 psi."Irontite" was used on the coolant passages after rebuild. LIke a number of sealer this is primarily Silicon Silicate.Would like to seal from outside if at all possible. Quote Selected
Porosity (continuing saga with the 18984, 3.8) Reply #1 – January 17, 2011, 12:37:24 PM Maybe a different intake..? Quote Selected
Porosity (continuing saga with the 18984, 3.8) Reply #2 – January 17, 2011, 02:01:02 PM Had thought about that -- but the question is whether all the 1983 castings (83 assumed since used on 1984) may have a similar problem.If they did, and the foundry sealed them, is there a MBTF (mean time between failure) for the sealer andare we nearing the MBTF because of vehicle age?From my reading, ALL aluminum castings have porosity issues and are sealed. A number of my questions are:1) What sealer was used or how was it sealed?2) Will milling the intake removes this seal enough to cause a bleed through?3) Will pressure washing or glass beading the intake remove this seal?4) Once sealed, can another sealer be applied and bind properly?Hoping someone on this forum has the "right" answers. Quote Selected
Porosity (continuing saga with the 18984, 3.8) Reply #3 – January 17, 2011, 05:33:01 PM did you sand blast this intake?unless you were blasting it at 100 psi upclose with coarse grit media i doubt you would do this from sand blasting it without noticing the intake was visually compromised. i personally never dealt with aluminum casting being "too porous" but id imagine that if it aint one of one just replace it, i dont think you can fix it. Quote Selected
Porosity (continuing saga with the 18984, 3.8) Reply #4 – January 17, 2011, 10:08:35 PM Based on my research (NET), I now know more about porosity in castings (both steel and aluminum) that I want to know. Kind of like all the research I had to do regarding ZDDP, flat tappet cams and cam failure.Appears to be a common problem, and most new castings appear to be sealed after they come out of the foundry. Want some good info try: http://www.impco-inc.com/.Near you in Providence, RI.Not sure how and to what level the rebuilder cleaned the intake. Definitely clean. Have a little MIL-Spec research still to do before I make a final decision.Thanks for response.David Quote Selected
Porosity (continuing saga with the 18984, 3.8) Reply #5 – January 17, 2011, 11:15:46 PM I know some of the more important items might have been anodized clear for a natural aluminum finish but enough to stop most corrosion, if not then it can certianly be anodized :) Quote Selected
Porosity (continuing saga with the 18984, 3.8) Reply #6 – January 18, 2011, 02:26:04 AM I doubt you will find any of the processes of buildiing our cars to be Mil-spec standard. too expensive. Milspec costs money, thats how you get a 10$ plastic flat washer. however, there is a guarrantee with mil spec stuff that far exceeds any civilian equipment and the manufacturer has to stand behind thier mil spec claim. Liability cost money,, and so the story goes about the 500 dollar hammer.However, I did turn to Rotella way back when you did the zddp research and have not turned back since.I did not know of this issue, interested to see the weaping of coolant you are talking about. Intersting , very.I am not really sure how you would make sure all the pours in the metal could be sealed without having it dipped.I imagine, just by common sense that you would want the intake fairly warm or even very hot in order to get best penetration. If thats the only pre req', then Id say any good shelack could be painted on then the residual sanded off after cool. that would defineatly seal up any porus openings. Quote Selected
Porosity (continuing saga with the 18984, 3.8) Reply #7 – January 18, 2011, 06:43:39 AM How about having it powdercoated? Seems like it would seal it pretty good.:D Quote Selected
Porosity (continuing saga with the 18984, 3.8) Reply #8 – January 18, 2011, 10:57:14 AM Thanks all for responding.Ideally I'd like to do this without pulling the intake. Location is easily accessible, but whether just doing a spot treatment of the area will allow bleed out around this area is unknown. Re: anodized and powder coatings. Good thought, hadn't considered either. Will check further.Re: MILSPEC -- Just using it as a reference to compare process solutions (options) and chemicals used. So far I know DOE (Dept of Energy) did a study using "silicon silicate" and had very favorable results. "Silicon silicate" is used in most of the after market products (Blue Magic CarCo, and Irontite, as examples). IMPCO has two products. Their IMPCO-800 which requires the intake to be heated to 500 degrees to draw in their product. They also have a cast-seal. Not sure what's in each -- maybe silicon silicate???.jcassity: Re: the $500 hammer or $1000 toilet seat I can give you a little background on this one.This is all media selling newspapers and getting the public in an uproar. What most likely happened is the contract was let as an RFP (request for proposal) not a straight 'bid". Since these items were part of a larger RFP, the contractor used these small items as a plug line to increase their total RFP value but keep their estimated profit on the RFP with in an acceptable range (say 5-15%). This way, if the RFP did not consider these items as a basis for evaluation, their proposal would be competitive with other contractor RFPs for those items (large $$) and the total cost of the RFP which most likely was being used as a basis for the award. For $1 or $2 billion dollar contract this would account for about .00000000000001% (did'n t calculate) of the total cost.A comparison would be paying $100 a night for a hotel room. The bed cost (say $500) and is replaced once every year or two, the maid is paid minimum wage (say $9.00) and spends 15 minutes cleaning each room, you got the manager salary and a few other people which needs to be divided by the total number of rooms in the hotel. So the biggest cost to the hotel is the mortgage. So should we be paying $100 a night or more for a hotel room. Who knows, but on the surface it seems outrageous.Yet this never makes the papers. Quote Selected
Porosity (continuing saga with the 18984, 3.8) Reply #9 – January 18, 2011, 11:06:42 AM Quote from: dw85745;350019Based on my research (NET), I now know more about porosity in castings (both steel and aluminum) that I want to know. Kind of like all the research I had to do regarding ZDDP, flat tappet cams and cam failure. Care to share?Not I know this debate goes on and on and there was a thread a while back but we never came to an ultimate conclusion, last time I saw. What motor oil viscosity and brand would be recommended for a stock 87 5.0 engine? What about motors from the 60-70's? Say an Oldsmobile 350, or a Chevy 350. Quote Selected
Porosity (continuing saga with the 18984, 3.8) Reply #10 – January 18, 2011, 11:39:53 AM jpc647If you don't object I'd like to keep this thread about porosity. If you start a new thread I'll reply, but -- first -- search forum for ZDDP. I think you will get your answer with the seach.David Quote Selected
Porosity (continuing saga with the 18984, 3.8) Reply #11 – January 18, 2011, 03:05:37 PM jcassity:Took a picture, but not sure how to upload to this site. Insert image wants a web page. Quote Selected
Porosity (continuing saga with the 18984, 3.8) Reply #12 – January 19, 2011, 11:10:15 PM yeah, its kinda tricky and different from the previous board.the steps / buttons are not actually self explaintory meaning it assumes a couple things.anyway, reply to thread but when done typing, scroll down and click on "go advanced".from there you can "manage attachements" and follow the promt instructions. Quote Selected
Porosity (continuing saga with the 18984, 3.8) Reply #13 – January 20, 2011, 09:18:10 AM Sorry for the bad pic. My cheap digital (got it free).The black dot at the bottom is the coolant that has pooled. Quote Selected
Porosity (continuing saga with the 18984, 3.8) Reply #14 – January 24, 2011, 12:51:30 PM jcassity:Guess I'm looking for a new or "good" intake for my 3.8. Know where I can get one? Quote Selected
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