View Full Version : FAST 102 not fitting properly on engine causing vacuum leak...


Snyper
07-18-2012, 04:30 PM
I have a ERL 434ci stroker with TFS245cc heads and an unported fast. The heads are brand new and never been milled and the block has been milled once when it was originally built and again by ERL. The issue I have is that right at around 2krpm I hear a sharp whistle. Its been doing it since day one. I also notice that at idle I have hardly any vacuum. It seems as though the intake isnt sitting flush on the engine. Ive removed the intake a few times and tried to reposition it. Ive had it apart 3 different times to check for cracks and found none. It seems as though the whistle could be air leaking past the port seals (they are brand new with no tears in any of them) and is causing all these issues for my car. If that is the case, how do I go about correcting this so that the intake sits flush on my engine?

ws602
07-18-2012, 06:41 PM
I have a ERL 434ci stroker with TFS245cc heads and an unported fast. The heads are brand new and never been milled and the block has been milled once when it was originally built and again by ERL. The issue I have is that right at around 2krpm I hear a sharp whistle. Its been doing it since day one. I also notice that at idle I have hardly any vacuum. It seems as though the intake isnt sitting flush on the engine. Ive removed the intake a few times and tried to reposition it. Ive had it apart 3 different times to check for cracks and found none. It seems as though the whistle could be air leaking past the port seals (they are brand new with no tears in any of them) and is causing all these issues for my car. If that is the case, how do I go about correcting this so that the intake sits flush on my engine?

What bolts did you use to hold the valley cover down?

BriancWS6
07-18-2012, 07:24 PM
What bolts did you use to hold the valley cover down?
Bingo! The button heads can keep the intake from resting flush on the valley cover. You may need to remove it and counter sink 9 outta the 11 holes, and replace those 9 with some countersunk head bolts like this. The two button heads by the OPSU will clear the intake.

http://i239.photobucket.com/albums/ff210/Brianws6/countersunkhead.jpg

Snyper
07-18-2012, 07:36 PM
I'm using the correct button head bolts.

BriancWS6
07-18-2012, 07:41 PM
It's the button heads themselves that can cause the issue. Countersinking the bolt holes and using the above pictured fastener allows the bolt to be flush or slightly below the valley cover surface, which in turn allows the intake to seat onto the heads properly.

spy2520
07-18-2012, 07:53 PM
is this an issue mainly with milled blocks/heads?

Snyper
07-18-2012, 09:43 PM
This is strange because last year with a different fast 102..I was using the factory bolts and had no issue. Is this a quality control issue? My friend is still using the intake..with his stock bolts no issue. Is it possible to temporarily run the valley cover with no bolts just to see if this fixes the issue..before drilling and wasting more time and money? Today I took the intake apart put silicone around the entire perimeter of the two pieces then put a very light coat of silicone on the heads around each port and the whistle changed spots..it seemed to be very quiet at first and then slowly get louder which means somewhere the sealant helped partially and then started to fail...I wish I knew which one made the difference.

litle88
07-18-2012, 09:58 PM
Spray some brake cleaner in the areas you hear the whistling. If the rpms jump then that's the spot.

Snyper
07-18-2012, 10:05 PM
I only hear whistling while driving and under light load around 2k.

BriancWS6
07-18-2012, 10:22 PM
I can't accurately answer if it's a QC issue, or what. I just know in the past some people have had interference with the factory bolts and even the smaller button head bolts, and this solved the issue.

Get a very good look at the intake as it sets now, then remove it, and remove the valley cover bolts and reinstall the intake and see if it appears to be seated better. I wouldn't advise trying to run it without the valley cover secured. It's sealed for a reason, and although it wouldn't be an intake leak, it's going to be an area of least resistance now for crankcase pressure, and could have an audible leak of its own, which isn't going to help you in tracking down the intake leak.

Snyper
07-18-2012, 10:32 PM
Well looking at the intake it looks completely flush against the heads. One way to tell I guess would be to remove the bolts put the intake on and check idle vacuum. Its high in the upper 80s and it should be in the 70s low 80s.

coops09gxp
07-19-2012, 10:21 PM
I saw this post and thought I would fill you in on some of the things I ran into with my FAST 102 intake. First, I had the same whistle that you mention, I looked for ever trying to find a vaccum leak and came up empty handed. At that time I was also running a Nick Williams 102 TB, I put the stock TB back on and the whistle was still there. What it ended up coming down to for my intake I think, and think is being the key word, is that it's just how my intake was molded. I talked with a lot of folks about this issue, some had the same exact thing and others did not.

One thing that I would stress, run a good size bead of silicone ALL the way around the intake where the top and bottom halfs meet where the orange foam rubber gasket rope thingy that FAST uses sits and especially in the lower front because of the goofy nature of how the two halfs join. If you take the two halfs apart, get a new orange rubber rope gasket thingy and do the same thing all over again making sure to clean out any left over silicone.

One other thing that I noticed and completely overlooked in alllll of the times I had mine off was where the intake meets the heads and where and what type of head bolts you use. I switched to ARP head bolts when I did my first head/cam package. Upon further inspection one of the last times I had it off I noticed that the intake was hitting and hitting pretty good on every single washer that is used on the ARP head bolts. The head bolts I am talking about are the ones that go into the block closest to the valley cover. I never noticed it before. It is something that definately needed fixing though. That is some thick and tough plastic and it put a good 1/16 inch divit on every single rib of the intake that just so happen to sit exactly over that particular head bolt. FAST probably could have spent a tad more time looking into this and maybe not put the support rib right over where a head bolt would be but we have what we have.

Best of luck trying to find or fix the source of your whistle. I never did have any vaccum leaks of any sort just the whistle, which had a lot of people asking me if I ran a supercharger lol! Again, GOOD LUCK!

Tony