Fel Pro 1250 Or 1262 ?

skiwesser11 · Mar 27, 2015

I currently have 1250's on AFR 165's and must remove lower, when I took off the upper I ran a vid scope to check for good lower to head fitment and I can see gasket in all ports, except mabye one.
The intake ports in heads are 2.060x1.250 according to AFR's site.
The 1250's are 2.00x1.20 while the 1262's are 2.10x1.28, so seems I'd want the 1262's but AFR's literature days use 1250's on 165cc head?
Any reason I shouldn't use the 1262's to get rid of any turbulence I feel I'm probably getting now?
Advice/input appreciated guys.

Gearbanger 101 · Mar 28, 2015

As long as it all lines up and nothing is leaking, go ahead an use em. I'd go with the 1262s3's though. They're the same gasket, but utilize a steel core to hold their shape. More durable than the standard 1262's for daily street use.

A5literMan · Mar 28, 2015

What he said

mikestang63 · Mar 28, 2015

1250s3 with the steel core will match your ports

skiwesser11 · Mar 28, 2015

Fit, yes.
Match, not so much.
Perhaps I should just trim the tops of the sc1250's I just figure if the 1262's would seal well as they a touch larger. I think ports on heads are actually 2.060x 1.206

skiwesser11 · Mar 28, 2015

*edit won't work they are 2.060x.1.25 or close to that(basically as advertised) I could be wrong but I believe thats what they measured.
Again, even .009 all the way around each port can't be good. With camera I can see gasket protruding into each intake port so it's a restriction I'd guess.
I'll have to check port sizes on the gaskets I'm replacing but they came with my Ebrock rpm II EFI so I think they're the same as steel core 1250 ?

Chuckman · Mar 29, 2015

the only steel-cored intake gaskets i know of are the 1250s3/1262s3, and the stock-replacement ms93334. the latter is really tiny, and not even big enough for a gt40 head. sounds like you really need the 1262-sized gasket (as mentioned, go with the s3, the normal 1262 and 1250 are way too easy to have leak). just be aware that the s3's dont have egr provisions (thought i'd point it out since an afr165 is an emissions-legal head).

i do find it odd though that the port on those small afr's have that kind of cross section though, the tfs170 is a larger (but shorter) port and is only 1250-sized.

skiwesser11 · Mar 30, 2015

I will remeasure to be sure, but bottom line is any gasket visible at all between heads/lower intake hinders flow, correct? So while its apart I shouldn't put same size back on, should I trim a 1250 to the head??
Thanks guys

Gearbanger 101 · Mar 30, 2015

skiwesser11 said:
I will remeasure to be sure, but bottom line is any gasket visible at all between heads/lower intake hinders flow, correct? So while its apart I shouldn't put same size back on, should I trim a 1250 to the head??
Thanks guys

Why don't you just buy one set of each and lay them on top of the head to see before making a decision. Keep the set that works, return the set that doesn't.

skiwesser11 · Mar 30, 2015

Gearbanger 101 said:
Why don't you just buy one set of each and lay them on top of the head to see before making a decision. Keep the set that works, return the set that doesn't.

Hmmm..... that's too sensable for my usual methods. Thanks for telling me what I should've thought of 3 days ago haha.
Seriously thanks, I wouldn't have thought of that, I'm sure I'd have ordered one or the other.

skiwesser11 · Apr 2, 2015

Fwiw, the 1262's fit best.

skiwesser11 · Apr 12, 2015

Also, fwiw, if I was buying intake/heads again I'd go with the 185's (at least, I'm 306ci so that played into decision to go with the 165's).
I got heads 12 yrs ago and I believe 185's are the norm on smaller engines now anyway, seems like 165's with 58 chambers were the hot ticket at the time.

At any rate I can still see maybe 2 or 3 mm of head at mating point with inspection camera at top of ports but no gasket as before.
I didn't have the heads off and I may have mentioned I certainly would not try to match them myself but even this small of an interference will probably result in not having optimum flow if only due to turbulence, correct?
I'm going by theory here but makes sense to me

A5literMan · Apr 12, 2015

^^^ agreed. It's not a big deal though.

skiwesser11 · Apr 12, 2015

A5literMan said:
^^^ agreed. It's not a big deal though.

Good, glad to hear that from someone other than me haha.
I hope that small of an "offset", if you will, would not cause any real loss of flow due to turbulence or tumbling or whatever physics is going on in there.
It's uniform to each port, plus I'll never know unless I get them port matched some day so I'm good with it.
Thanks 5liter

Fel Pro 1250 Or 1262 ?

skiwesser11

Gearbanger 101

Straight Outta Locash

A5literMan

At least it is lumpy...

mikestang63

skiwesser11

skiwesser11

Chuckman

GTFO you fat, heavy bastard

skiwesser11

Gearbanger 101

Straight Outta Locash

skiwesser11

skiwesser11

skiwesser11

A5literMan

At least it is lumpy...

skiwesser11

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