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Is this a vacuum leak from the intake

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Old 12-18-2009, 04:18 PM
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Is this a vacuum leak from the intake

I pulled my HSR off my motor today I've been trying to tune it but have not been able to. So I pulled the intake and the the intake ports on the head are white and on the left bottom corner of each port has a dry black trail going down it. I took some pictures I'll try to put them up here. The heads are ported to 1206. let me know what you think.
Attached Thumbnails Is this a vacuum leak from the intake-pc150165.jpg   Is this a vacuum leak from the intake-pc150167.jpg   Is this a vacuum leak from the intake-pc150164.jpg  
Old 12-19-2009, 09:28 PM
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Re: Is this a vacuum leak from the intake

hmm not sure.

did u try propane around the intake ports while it was running to see if the idle raised? looks to be like it could be a leak, the black lines could be the leak and the heads could be sucking oil from the valley in the corners. the white seems like a lean condition but its on the exhaust side. what kind of tuning issues where u having? i tuned mine and i had issues untill my rockers were adjusted correctly, then tunning was easier (rockers basically acted like a vacume leak) made idle tuning a PITA! then my lifters took a dump and whiped out my cam

btw uve got water in the valley, be sure to clean that out well. and your bottom end/shortblock is rather stout for ur engine combo.

i would check the sealing surface on the head an intake to make sure they are true too. either they didnt seal bc they wherent tq'd correctly, the surfaces arent flat or you took too much material off the gasket match and theres not enough sealing surface. I ALWAYS use black RTV on the intake gaskets on both sides around the ports and water jackets... never get a vacume leak and portmatched my stealth ram and heads to 1206 and i have wayyy less sealing surface on my HSR.

seen here, i basically ported my HSR to that gasket intake port line thats in your pic... so i have like 1/16-1/8" sealing surface for my intake gasket. but the transition from intake-head is smooth as a babies A$$!
https://www.thirdgen.org/forums/alte...cc-ported.html
Old 12-20-2009, 10:03 AM
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Re: Is this a vacuum leak from the intake

When I took it off I noticed the corner bolts were harder to get off. After inspecting it I saw that the holes don't really line up. I think that's why it was leaking. I'm gonna try a thicker gasket and see if I can get the intake to move up a little. The guys that did my heads did shave a little off so that might be my problem. And I had every tuning issue you could think of. Couldn't even get the car to idle long enough for me to tune it. Hopefully this will fix my problems along with Holley's new Dominator ECU.
Old 12-20-2009, 12:50 PM
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Re: Is this a vacuum leak from the intake

vacume leaks will make it impossible to tune. what injectors are u using and how were u trying to tune it?

wat intake gaskets are thicker? and how much did they take off? did they take it off the head gasket surface or the intake gasket surface?
Old 12-20-2009, 01:01 PM
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Re: Is this a vacuum leak from the intake

I was using 22 bosch inj. I just switched to 30lb TrickFlow inj. I was using FlePro 1206 .060 Now I'm going to try the one that's .120 thick. I forget how much they removed but it was off of the head gasket surface. I just got back from Afghanistan and all of this was done over a year ago right before I left. So now I'm trying to get back into it. I was using the Ostrich which was impossible for me. I ordered the C950, but now that Holley has the new ecu systems coming out by Feb I'm waiting for the Dominator ECU. Seems much easier and will run everything from the 4l60e tranny, ac, cooling fans, and so on.
Old 12-20-2009, 07:41 PM
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Re: Is this a vacuum leak from the intake

22lb were probably not enough injector for ur setup... i would have went with 24lb... u could still prob use the 24lb.... i feel like the 30lbs might be alittle too much for ur engine... 30lb is set for like 500-550hp. id say ur in the 400-420range. in which case i would use the 24lb at a higher pressure like 48-50psi. im using the SVO 30lb on my 383 with about 470hp.

i tuned mine with tunerpro no RT or anything, just test and tune. its alot of change alittle and see wat happens... pita tho
Old 12-20-2009, 08:16 PM
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Re: Is this a vacuum leak from the intake

I went with 30 due to other plans I have for this motor down the road. Next summer I planned on supercharging it. That's why I have such strong bottom end. I figured I could dumb down the fuel pressure if the 30s are too much right now. Yeah I'm no good at all with tuning. That's why I'm going with holley's new ecu. They are self tuning. I just don't have the time to mess with it that much.
Old 12-28-2009, 11:37 AM
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Re: Is this a vacuum leak from the intake

watev u do dont run the bosch injectors less than like 40psi... or they will cause issues. GM injectors arent designed to run lower than 43.5psi but the ford injectors are designed to flow normally at 37.5psi. lowering the pressure too much on the GM injector will cause the injector to shut off or sputter/spit or just dribble fuel. you could also get spiratic fuel firing
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