NewbVetteGuy

I laid my bead of gray RTV on my china walls and tried to install my intake yesterday and found that I could only get the bolt holes on one side to line up. I really SHOULD HAVE elongated the intake bolt holes...

What are the factors that can make this happen?

-My block has never been decked, I have new heads that haven't ever been machined down, and I used the head gasket recommended by the MFGR...


At this point, I forced the intake to fit and probably majorly screwed up at least one bolt hole in one head, but the intake is on.... I'd love to just understand what factors can throw off the intake to head bolt hole alignment just so I know, though...




Thanks,
Adam

bashcraft

How did you force it to fit if the holes didn't line up?

HeadsU.P.

Vortec heads?

You used head gasket recommended by . . . .
But what intake gasket? They come in two thicknesses if the intake is too far away, use the thickest.

C3 Stroker

Were the heads (or the intake) ever milled? That would make a mis-match.

derekderek

start with intake with no gasket. see how holes line up intake should be down a little too deep and all holes seem too high. now put the rubber pieces on china walls and see how holes line up. if they look ok, i put sealer under the gasket side pieces and drop intake on using rubber china wall ends and get bolts to start. go back in an hour or next day. pull intake and check gaskets for location. use sealer on china walls instead of rubber pieces and install the gasket.

NewbVetteGuy

Not vortec heads or intake.
Nothing ever milled.

Holes would've fit up pretty well without a gasket at all, I think.
I used gaskets on the heads; RTV on china walls.

It was like the intake needed to sit lower than was possible. I could get 3/4 - 4/5" of a bolt hole on each side in the very bottom of the intake's holes.
-I "forced it" by getting like one thread started on bolt #1 and #1 on opposite sides of the intake started and then applying some good downward force with my ratcheting T-handle alan head wrench (bolts for this intake are stainless alan head bolts)- the #1 bolt started slightly vertical of where it should be- my thinking was that if I could just manage to get 2 bolts started and snug that they'd compress the gasket and make more room for the other holes. This largely worked except the #1 bolt went in kinda crooked / too verticle and didn't straighten out as it went in. I think it DID work to compress the gasket just enough that the others went in straight. I should've removed a tiny bit of material from the bottom of each intake hole, though. #1 bolt hole in the head is definitely screwed up. The others were still really tight going in, so who knows? I don't know what it's SUPPOSED to feel like going in, but it didn't feel right.

Hopefully, I got lucky for once and there's no vacuum leaks and I won't need to worry about it for 10 years. ;-)


Adam

NewbVetteGuy

The intake gasket supplied by Ken @ FIRST (the intake MFGR) -he ported the intake to a Felpro 1206 size to match the heads and then provided a generic gray gasket very well matched to the ports.
I probably could've used an ultra-thin gasket, actually.


Adam

jackson

First fit should have been dry.

REELAV8R

Yes. NVG these are aftermarket parts, never assume anything fits until you measure and or fit it first, then apply sealer or do final assembly. I recall a harmonic balancer incident recently.

I hope the stainless bolts got some anti-Seize...no scratch that, thread sealant, before they went into aluminum threads.

HeadsU.P.

If it were mine, I would remove the intake and start over. You shouldn't have to force fit a part like that. Somethings not right and you need to address the issue before you snap "ears" off the intake, strip the threads or snap bolts off in the cyl head. Slow down and think this through.
Flip the intake up-side-down. Inspect the mating surface that would attach to the china wall. If you think about it, the china walls are the only two places the intake has any contact with the short block. There should be a slight gap at the heads, no contact.

jackson

I agree start over & take your time ... & when you begin to feel a problem STOP and ask for insight

Heads: holes-threads not located correct ... surfaces milled incorrect.

Intake: holes not located correct ... surfaces milled incorrect.

two separate manufacturers/suppliers ... expect finger pointing.

7T1vette

Before assembly, one should dry-fit the intake on the block/heads assembly to see how the bolt holes line up and how much gap there is in the 'valleys'. That should give you some idea of how thick the intake-to-head gaskets need to be for everything to line up at final assembly.

If none of the parts have been milled (engine block, head surfaces [intake or cylinder face], and/or intake), the problem must be the gasket thicknesses (cylinder head, or intake head). But, my 'guess' is that something HAS been re-machined.

427Hotrod

Need to take it apart and do it right. What intake? It's not uncommon to have to elongate the holes on some intakes...MFG's just can't seem to get holes correct even on something as common as a SBC. Hopefully you can run a thread chaser through the bad threads and clean them up. It will be a LOT harder to do all of this in the car later.


JIM

bashcraft

Sounds like it's cross threaded. Are you going to leave it like this?

NewbVetteGuy

YES THIS!
If anyone is lucky enough to stumble across this thread immediately PRIOR to their first intake install: FIT IT DRY FIRST!
-This would've quickly shown the issue and then I wouldn't have felt so rushed to get it done before the RTV started drying and setting up...

Adam

NewbVetteGuy

I did THAT right, at least. I used ARP Thread Sealant on all bolts. I like it because it's supposed to help keep torque readings consistent, seal, and supposedly never dries out.

For the stainless bolts that hold down the thermostat housing, bolt the runners to the base, and bolt the runners to the plenum, my plan is to use anti-sieze on all except for one bolt, which explicitly requires thread sealant because it goes into water/ coolant.

I've test fit the runners and plenum a gazillion times at this point so I'm pretty confident there.


Adam

NewbVetteGuy

Anyone happen to know the right bolt size / thread count for a tap to chase the intake-to-head bolt holes?!?

(Anyone know the right specs for the various coolant plugs in the intake too? -They were honestly TERRIBLE from the MFGR; I went to a hardware store with a plug this weekend and they seemed to think it was some weird non-standard thread count for the 1/2" plugs so I ran away. The guy who's normally there who really knows what he's doing was gone and it took these guys way too long to come up with a really weird answer and I'm just tired of screwing stuff up.


Adam

HeadsU.P.

In the future, you should act like Saturday nite hot rodders. They would just sit the intake on the short block. Stand back. Open beer. Stare at what they just did. Eye -ball it some more. Drink another beer. Then think about actually attaching the intake. Its a two hour process.

And I believe its 3/8 - 16

NewbVetteGuy

Yep. This is very close to the root cause on essentially all of my big "oopies" so far. --I've got basically 2 hours a weekend do work on the car and I feel like I absolutely have to rush and get something accomplished; I'm in GIT-R-DONE mentality and it means I push-through things when I should stop.

Early on in my build when all the new parts were rolling in and I got to disassemble the heads and the intake and just spend my time with it, it was really fun making sure to get it done right and going slow. Now that I'm at like 7? 8? months since I started I've shifted to "just get the 2#$#@ thing done" mode and what do you know? -Now I'm breaking stuff.

I also mistakenly thought that buying a step-by-step SBC rebuild guide would actually tell me everything I need to check and do and if it's not in the book then I don't need to do it. (See: ATI harmonic balancer install and needing to hone the balancer before trying to install it.) I also thought "hey it's just a SBC, it's the most sold v8 engine and maybe the most sold engine in the world, PERIOD, there's no way a MFGR would sell you a $1,000+ part for one of these that isn't perfect/that won't just bolt-up..."
*Breaking out Harmonica* -Lol!

Adam

drwet

Almost certain the block has been decked and/or the heads have been milled. The solution is to mill the intake the appropriate amount to match.