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1/2 smokin' 290 HP crate motor

2K views 15 replies 5 participants last post by  rumbo428 
#1 ·
Hello to All,

New to these forums but have been working on and restoring musclecars for years. Project for this past week was trying to get buddy's 75 Vette w/recently installed (1500 miles) 350/290 HP GM crate motor installed to quit smoking. Checked all of what I thought to be most possible problems, and have found nothing conclusive. Only smokes out of passenger side pipe, and only after fully warming up and sitting at idle. Intake appeared to have leaks on underside, installed new gaskets and checked alignment and still smokes. Compression is +/- 125 psi across the board and new valve seals have already been installed. Have found similiar threads on other forums, but no conclusive diagnosis or cure. Just wondering if anyone else had experienced a similiar problem and what, if anything, was the cure. For the record, intake is Edelbrock Performer 2101 and has been instaled with and without end seals. Makes no difference. Any ideas out there? Thanks in advance for any and all help/tips.
 
#3 ·
Pretty much think the valve guides are ok. New seals went on pretty nice. Only thing I did notice was that the heads were machined a little deep at the spring seats, but the guides seem OK. Hard to believe that a set of GM heads w/only 1500 miles on them could have trashed the guides, I thought. I'm almost to the point that I think the Performer 2101 intake is not compatible with these heads or something else freaky. It's really odd. Gonna wait till morning and call Edelbrock Tech line, see what they have to say. The guides were my first thought, though, so I changed seals right away and as sonn as engine warmed up, it started smoking again, passenger side only...wierd!!
 
#4 ·
Rumbo428,

If it has an automatic transmission with a vacuum line running down to the modulator you could be pulling transmission fluid into the engine. The vacuume would be near the passenger side of the engine so I would check that out.

Also if you have vacuum assist brakes you could be pulling in brake fluid too.

Just some things to check out.

Scholman
 
#5 ·
Actually, checked both of those alraedy. Disconnected and plugged both lines at intake to eliminate any possibility of trans or master cylinder having bypass conditions and problem remained. Thanks for the reply, though. Like I say, I'm really puzzled by this one because I've checked pretty much everything a guy can normally check to eliminate the source of oil/foreign fluid being drawn into the cylinder.
 
#7 ·
Used fel-pro on last try. As I said, I think a call to Edelbrock in the morning is the right call. I seem to recall I had some intake leak problems on a Ford 289 motor once, and switching over to the correct Edelbrock gasket cured it. Checked all the sealing areas after I pulled intake this time, all looked good to naked eye, but I'm just wondering if there's enough of a differential in the expansion of the Edelbrock intake in this case that a leak is going to occur at operating temp unless the "Real McCoy" Edelbrock .060 thick gaskets are used.
 
#8 ·
1/2 smokin 290 hp crate

Correct gasket is Fel-pro Printoseal, Mr. Gasket Ultraseal type, Not the Permatorque Blue version. Seems like Edelbrock's version is the same style gasket--fiber core with raised silicone bead around each port. If it has a metal core in it, it is the wrong type. :nono: :thumbup:
 
#11 ·
Yes, has enough of a bluish tint to it that I'm quite certain it is oil. Pulled intake back off testerday afternoon and noticed gaskets were pretty much oil soaked about 1/2 way up. Pretty confident now that we have intake leak on underside of manifold creating oil draft effect out of valley. Going to check manifold for warpge, flaws, etc, and the reinstall w/new MR. Gasket intake gaskets as opposed to FepPro blue "permatorques." Never have had a problem with the Felpros, but there is an overwhelming amount of info on the various web sites talking about the incompatibility of Edelbrock intakes with anything but their own or Mr Gasket gaskets, both of which have the raised silicone beads around the port openings for a more positive seal. I always tend to dismiss these warnings as sales pitches, but at this point it's certainly worth looking into. Thanks for your reply though...will let you know what happens.

Phil Rambo
 
#12 · (Edited)
1/2 smokin 290 hp crate

The Permatorque Blue are designed for iron to iron installations and the equal expandtion rates when heated, aluminum expands more than iron and crushes gasket more when hot, then when it cools the "P-Blues" can't spring back and you get a leak, usually on the intake valley side to oil..once oil tracks acrossed a gasket, it wont seal again. The fiber style springs back more(is more forgiving) and the silicone bead adds to that. :thumbup:
You also might check into the 1/8" thick versions of these gaskets also.
 
#13 ·
That's exactly what it ended up being. Went this mormning to nearby Lee Auto Parts and grabbed a set of Mr Gasket 5280's and installed them, using silicone at ends instead of rubber seals. Torqued down, fired up and ran it for about 15 minutes. Residual oil in cylinders, port runners, exhaust, etc, finally burjned off, smoke cleared, and I'm in a much better frame of mind. Also, retorqued manifold while warm just to make sure. Everything seems good for now. Thanks to everyone for the response.

Phil Rambo
 
#16 ·
Believe me, I learned that the hard way the past couple of days. Finally ended up installing 3rd set of gaskets today (Mr Gasket 5280's) and retorquing after warming engine to compensate for any differential temperature expansion/warpge and finally got rid of this oil drafting.

Hallelujah!!!

Thanks for all the replies, though. Always thought Edelbrock's insistence on using their gaskets was just a sales ploy, but, as you and several other folks pointed out to me, it's just that they know how "unstraight" or imperfect their manifolds are from time to time.
 
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