Rembrant Posted November 11, 2019 Author Share Posted November 11, 2019 Hard to believe they did such a poor job of the intake install. Breaking the gaskets is hard to do, but I'd guess that they put studs through in the center to hold the gasket and align the manifold, and then they had to press hard to get it down on the ends. And since it was sandwiched between the head and the intake the gasket couldn't fold over so tore. And then to put them on backwards as well. Even lowly Chevys should be treated better than that! Gary, I have to own some of this as it was me that purchased the gaskets and then supplied them to the engine shop with boxes full of other parts. However...they still should not have installed them backwards...and if they had checked the part number they would have found out that they were not supposed to be used for my application. Since it was me that supplied the gaskets, I'll take the blame for that. Installing them backwards was not a big issue really. I talked to Fel-Pro tech support and the guy was really helpful. He said it is a big "No No" to use the MS90361 gaskets with an aluminum intake. They are strictly for stock applications with cast iron heads and cast iron intakes. He said that aluminum intakes are not strong enough to put enough equal force on the gaskets to crush the perforated steel cores. The result is all kinds of vacuum leaks and related issues. I told him how the gaskets were both broken, and he said it was likely due to the combination of the aluminum intake and maybe being over torqued. It makes the gaskets "walk" because the aluminum intake flexes and can't crush them in place like a cast iron intake would have. Makes sense to me I guess. Anyway...onward and upward. I feel much better knowing why everything happened. They recommended the 1250 gaskets, or the even heavier duty 1250S3 version. They'll be on order today. Link to comment Share on other sites More sharing options...
Rembrant Posted November 13, 2019 Author Share Posted November 13, 2019 Hard to believe they did such a poor job of the intake install. Breaking the gaskets is hard to do, but I'd guess that they put studs through in the center to hold the gasket and align the manifold, and then they had to press hard to get it down on the ends. And since it was sandwiched between the head and the intake the gasket couldn't fold over so tore. And then to put them on backwards as well. Even lowly Chevys should be treated better than that! Gary, I have to own some of this as it was me that purchased the gaskets and then supplied them to the engine shop with boxes full of other parts. However...they still should not have installed them backwards...and if they had checked the part number they would have found out that they were not supposed to be used for my application. Since it was me that supplied the gaskets, I'll take the blame for that. Installing them backwards was not a big issue really. I talked to Fel-Pro tech support and the guy was really helpful. He said it is a big "No No" to use the MS90361 gaskets with an aluminum intake. They are strictly for stock applications with cast iron heads and cast iron intakes. He said that aluminum intakes are not strong enough to put enough equal force on the gaskets to crush the perforated steel cores. The result is all kinds of vacuum leaks and related issues. I told him how the gaskets were both broken, and he said it was likely due to the combination of the aluminum intake and maybe being over torqued. It makes the gaskets "walk" because the aluminum intake flexes and can't crush them in place like a cast iron intake would have. Makes sense to me I guess. Anyway...onward and upward. I feel much better knowing why everything happened. They recommended the 1250 gaskets, or the even heavier duty 1250S3 version. They'll be on order today. Alright, new intake gaskets are on order with an ETA of tomorrow (or next Tuesday...lol). Going with Fel-Pro 1250 "Print-o-seal gaskets. I picked up a new coolant bypass hose yesterday since I cut the old one off, and last night I started the unfun task of scraping the old gaskets off the cylinder heads. How do you guys with the 4x4's work on the engine?...Ugh... Technically, I should have it all back together this weekend, but I took this downtime opportunity to send my DSII distributor out to Scott at Parkland for a checkup and fine tuning. It is probably fine, but it will give me peace of mind if somebody else looks at it and really optimizes it. (PS: several times in the past couple years, there have been old distributor machines pop up for sale around here, and I REALLY wanted to buy one...but it really wouldn't make sense for just one distributor, and I have no space for one, blah blah blah.). I've spent some time screwing around with my Holley and I think I have it dialed in even better now as well. I have the throttle plates set so that I can close them just past the transition slots with the idle speed screw. This I could not do before. I was trying to figure out how to measure how much of the transition slot is exposed at idle, and I read yesterday that you can use wire....which is a great idea, but where do I get wire that is 0.040"?...I must go rummage around the garage and see what I have. Anyway...I'm on the road to recovery here...I think. I had several problems here all compounding each other, and I'm optimistic that this thing will run much better when it's all buttoned back up (and is vacuum leak free). Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted November 13, 2019 Share Posted November 13, 2019 I read yesterday that you can use wire....which is a great idea, but where do I get wire that is 0.040"?...I must go rummage around the garage and see what I have. Do you have a set of number drill bits? #61 is .039", and I would call it close enough..... Link to comment Share on other sites More sharing options...
Rembrant Posted November 13, 2019 Author Share Posted November 13, 2019 Do you have a set of number drill bits? #61 is .039", and I would call it close enough..... No, I do not...and the smallest bits I have would be 1/16", which is what?...0.060"? Anyway, I just thought of one of those torch tip cleaner kits, and when I went to check if I had one, I found a pin-tool set I had purchased years ago for cleaning motorcycle carb jets. It's metric, but there's about 20 of them and the sizes go in 0.002" steps, so that will work. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted November 13, 2019 Share Posted November 13, 2019 Do you have a set of number drill bits? #61 is .039", and I would call it close enough..... No, I do not...and the smallest bits I have would be 1/16", which is what?...0.060"? Anyway, I just thought of one of those torch tip cleaner kits, and when I went to check if I had one, I found a pin-tool set I had purchased years ago for cleaning motorcycle carb jets. It's metric, but there's about 20 of them and the sizes go in 0.002" steps, so that will work. 39 thou is also 1mm, so there is that.... Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 13, 2019 Share Posted November 13, 2019 39 thou is also 1mm, so there is that.... I've used a spark plug gapping tool, the ones with the single wire rather than the loop. Link to comment Share on other sites More sharing options...
85lebaront2 Posted November 13, 2019 Share Posted November 13, 2019 Alright, new intake gaskets are on order with an ETA of tomorrow (or next Tuesday...lol). Going with Fel-Pro 1250 "Print-o-seal gaskets. I picked up a new coolant bypass hose yesterday since I cut the old one off, and last night I started the unfun task of scraping the old gaskets off the cylinder heads. How do you guys with the 4x4's work on the engine?...Ugh... Technically, I should have it all back together this weekend, but I took this downtime opportunity to send my DSII distributor out to Scott at Parkland for a checkup and fine tuning. It is probably fine, but it will give me peace of mind if somebody else looks at it and really optimizes it. (PS: several times in the past couple years, there have been old distributor machines pop up for sale around here, and I REALLY wanted to buy one...but it really wouldn't make sense for just one distributor, and I have no space for one, blah blah blah.). I've spent some time screwing around with my Holley and I think I have it dialed in even better now as well. I have the throttle plates set so that I can close them just past the transition slots with the idle speed screw. This I could not do before. I was trying to figure out how to measure how much of the transition slot is exposed at idle, and I read yesterday that you can use wire....which is a great idea, but where do I get wire that is 0.040"?...I must go rummage around the garage and see what I have. Anyway...I'm on the road to recovery here...I think. I had several problems here all compounding each other, and I'm optimistic that this thing will run much better when it's all buttoned back up (and is vacuum leak free). I really wouldn't fret about the transition slot, but, if you have a nice set of calipers that include a depth gauge slide, you can measure the distance from the base to the end of the slot then from the base to the throttle plate edge to get the difference. On pre-emission carburetors it was actually above the throttle plate, hence the term "transition slot". It's function was to allow fuel from the idle circuit that was not adjusted by the mixture screws into the air stream to help in the transition to the main fuel feed from the booster venturii. When the first emission systems were introduced (1966 in CA, 1968 49 state) one of the methods used was to retard the initial timing, which (a) required more throttle opening and (b) allow a leaner idle mixture. Each of the "big three" used different approaches, and in GM's case, each division was different. The two primary approaches were either air injection or engine modification. Ford used a combination, automatic transmission vehicles got the engine modification, manual transmissions got air injection. The retarded initial timing and resulting increased throttle opening meant the engines were idling with the transition slots uncovered, this essentially converted the old idle mixture screws into mixture trim screws and on many carburetors you could turn them out to the point of falling out and never get the mixture too rich. The other nasty trick that Holley pulled, the idle mixture screws were actually air bleed screws that worked backwards, in for rich, out for lean. This was done to comply with CARB and EPA regulations. Link to comment Share on other sites More sharing options...
Rembrant Posted November 14, 2019 Author Share Posted November 14, 2019 I really wouldn't fret about the transition slot, but, if you have a nice set of calipers that include a depth gauge slide, you can measure the distance from the base to the end of the slot then from the base to the throttle plate edge to get the difference. On pre-emission carburetors it was actually above the throttle plate, hence the term "transition slot". It's function was to allow fuel from the idle circuit that was not adjusted by the mixture screws into the air stream to help in the transition to the main fuel feed from the booster venturii. When the first emission systems were introduced (1966 in CA, 1968 49 state) one of the methods used was to retard the initial timing, which (a) required more throttle opening and (b) allow a leaner idle mixture. Each of the "big three" used different approaches, and in GM's case, each division was different. The two primary approaches were either air injection or engine modification. Ford used a combination, automatic transmission vehicles got the engine modification, manual transmissions got air injection. The retarded initial timing and resulting increased throttle opening meant the engines were idling with the transition slots uncovered, this essentially converted the old idle mixture screws into mixture trim screws and on many carburetors you could turn them out to the point of falling out and never get the mixture too rich. The other nasty trick that Holley pulled, the idle mixture screws were actually air bleed screws that worked backwards, in for rich, out for lean. This was done to comply with CARB and EPA regulations. Quick and possibly dumb question... My gaskets are supposed to be here today so if all goes well I'll be reinstalling my intake manifold. I left the thermostat housing bolted to it since it is well sealed and working fine. Can the short coolant bypass hose be installed with the thermostat housing in place? Or do you usually have to remove the thermostat housing for this? It's a pretty tight little bend on the 302... Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 14, 2019 Share Posted November 14, 2019 Quick and possibly dumb question... My gaskets are supposed to be here today so if all goes well I'll be reinstalling my intake manifold. I left the thermostat housing bolted to it since it is well sealed and working fine. Can the short coolant bypass hose be installed with the thermostat housing in place? Or do you usually have to remove the thermostat housing for this? It's a pretty tight little bend on the 302... I've done it on vehicles that just had a bad hose. It can be done. Link to comment Share on other sites More sharing options...
85lebaront2 Posted November 14, 2019 Share Posted November 14, 2019 Quick and possibly dumb question... My gaskets are supposed to be here today so if all goes well I'll be reinstalling my intake manifold. I left the thermostat housing bolted to it since it is well sealed and working fine. Can the short coolant bypass hose be installed with the thermostat housing in place? Or do you usually have to remove the thermostat housing for this? It's a pretty tight little bend on the 302... Stick it on the intake before you drop it on, it will not be too difficult to guide it over the pump nipple. Be glad it's not an FE or 385 series, those can be a real PITA to install, even with an aluminum intake. Link to comment Share on other sites More sharing options...
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