318 engine combination

-
69dart340hemiorange

69dart340hemiorange

Member
Joined
Apr 28, 2018
Messages
21
Reaction score
2
Location
Pennsylvania
This has probably been asked many times before. Will a 318 bored .030 with kb167 pistons, #302 heads, comp cams xe268h, weiand 8007 intake, and 600 cfm carb be a good combo? What will the comp ratio be and what would the approximate power numbers be? It will be in front of a direct a833 and 3.73 gears.
 
69dart340hemiorange said:
This has probably been asked many times before. Will a 318 bored .030 with kb167 pistons, #302 heads, comp cams xe268h, weiand 8007 intake, and 600 cfm carb be a good combo? What will the comp ratio be and what would the approximate power numbers be? It will be in front of a direct a833 and 3.73 gears.
Click to expand...
Subscribe d
 
in general, sounds like a decent combo. With your gears and 4 gear, i personally would like a better flowing head.
 
69dart340hemiorange said:
This is what I'm doing for now and see how I like it, if not I will go with a set of eddy heads.
Click to expand...
well, 302's to eddy, that's kind of a pendulum swing... LOL.
Ok, i'll answer your questions in order:
  1. doesn't matter if it sounds like a good combo, because it's what you are doing for now. If you don't like it, you'll change it. were ok with that.
  2. Compression ratio is anybody's guess. It would all have to be CC'd to know
  3. Power numbers should range between 100 hp and ???, depending how well you can tune, what type of 600, and a bunch of other info that is missing.
but, i think what you were looking for was this remark, so I'll say it. "Cool build, should scoot, keep us posted" :)
 
318willrun said:
well, 302's to eddy, that's kind of a pendulum swing... LOL.
Ok, i'll answer your questions in order:
  1. doesn't matter if it sounds like a good combo, because it's what you are doing for now. If you don't like it, you'll change it. were ok with that.
  2. Compression ratio is anybody's guess. It would all have to be CC'd to know
  3. Power numbers should range between 100 hp and ???, depending how well you can tune, what type of 600, and a bunch of other info that is missing.
but, i think what you were looking for was this remark, so I'll say it. "Cool build, should scoot, keep us posted" :)
Click to expand...
I'm looking at a summit racing 600 cfm vacuum secondary carb (around a 67 main jet and 73 secondary) 1" spacer, long tube hookers, pypes violator exhaust, factory tips, hei distributor, and I will be tuning with a vacuum gauge and Afr gauge
 
69dart340hemiorange said:
I'm looking at a summit racing 600 cfm vacuum secondary carb (around a 67 main jet and 73 secondary) 1" spacer, long tube hookers, pypes violator exhaust, factory tips, hei distributor, and I will be tuning with a vacuum gauge and Afr gauge
Click to expand...
I was contemplating with those #302 heads to do some port and bowl work to them and get 1.88/1.60 valves put in
 
69dart340hemiorange said:
I was contemplating with those #302 heads to do some port and bowl work to them and get 1.88/1.60 valves put in
Click to expand...
This would really help the rest of your combo. Not sure if you want suggestions, but i was going to suggest 360 heads. Bigger ports, bigger valves. When it comes to performance, and i have to choose, I always take flow over compression. I would home port the bowl area of 360 heads, and do some "slight" touch up to the ports.
 
318willrun said:
This would really help the rest of your combo. Not sure if you want suggestions, but i was going to suggest 360 heads. Bigger ports, bigger valves. When it comes to performance, and i have to choose, I always take flow over compression. I would home port the bowl area of 360 heads, and do some "slight" touch up to the ports.
Click to expand...
I could do the 360 heads with the minor port and bowl work and get the block decked to get it close to zero deck and get thinner head gaskets to help bump compression a little
 
69dart340hemiorange said:
I could do the 360 heads with the minor port and bowl work and get the block decked to get it close to zero deck and get thinner head gaskets to help bump compression a little
Click to expand...
you could, but you'd want to CC it all first to see where you are at. A true 8.5 to 1 works well with todays gas, and will perform well. If you want a little more compression, cut the heads .040 for a slight bump. I've done this many times, and I've never cut the intake side either. Never had an issue.
 
are you porting heads per sticky at the top of the page?
have you ccd your heads do all 4 end chambers
KB shows compression height 1.82
block 9.578
rod 6.123- less if rebuilt
Centered pin. Piston is .010" above 9.578" deck.
Compression Ratios
57cc-10.4
60cc-10.1
64cc-9.6
68cc-9.2
so how big are your heads and what are the ccs of the gasket you want to use
cheers
sounds like a good combo AVS or TQ
forget cam till you get ccs there is another thread discussion cams for 318s but not with stick and gears
WHAT EXHAUST? and is this a daily driver or weekend warrior?
 
I started the post and came back to it and found some questions answered

you can't mill open chambered heads to get quench

he will have positive deck

69dart- is your 318 still together?

If you pull the heads measure the deck clearance at all four corners before your remove the pistons

your machinist will need to know this before you square up the block or if you don't

That piston has positive deck so squaring up the block determines how far out of the block the pistons come- not a problem but you may have to juggle head gaskets - especially with closed chamber heads like the Edelbrocks

If piston is out 10 and you have a .040 gasket – well depends on if any of the head surface overhangs the bore

also check your rods for being angle cut on the caps

agree flow trumps compression (more fill needs less squeeze)

8.5-9:1 true compression for iron heads (unless big big cam, late intake close to bleed off compression)

agree on ir3333 comp cam suggestion but put that off (and I do not use comp cams much)

is the summit carb avs or afb both good avs better
you do not want large tube headers
 
Let's fix some errors: The deck height above seems a bit low, even for a Magnum block. An LA block will have around 9.599-9.600" deck height. So with a 1.810 compression height, these pistons will end up about .012 below deck in a LA block. No problem to get about .040" quench with a .028" head gasket (Mr Gasket 1121G).

So OP, what year is your 318 block? We just need to know if it is before or after '92 IIRC to decide if it is an LA or Magnum block.

With 64 cc chambers (my recollection for the 302's but check me on that) and a .028" head gasket, that is around 9.5:1 in an LA block.

OP, what do you intend to do with this engine? Drag race? Road race? Circle track? Cruise? That has a lot to do with what you decide next. You asked about how much HP.... that can be all over the place, depending on the cam and the in and out breathing bits. But the cam should not be chosen for peak HP alone; it will decide the 'character' of the engine and should be tailored more for the intended use. So let us know a bit more of how this will be used.
 
nm9stheham said:
Let's fix some errors: The deck height above seems a bit low, even for a Magnum block. An LA block will have around 9.599-9.600" deck height. So with a 1.810 compression height, these pistons will end up about .012 below deck in a LA block. No problem to get about .040" quench with a .028" head gasket (Mr Gasket 1121G).

So OP, what year is your 318 block? We just need to know if it is before or after '92 IIRC to decide if it is an LA or Magnum block.

With 64 cc chambers (my recollection for the 302's but check me on that) and a .028" head gasket, that is around 9.5:1 in an LA block.

OP, what do you intend to do with this engine? Drag race? Road race? Circle track? Cruise? That has a lot to do with what you decide next. You asked about how much HP.... that can be all over the place, depending on the cam and the in and out breathing bits. But the cam should not be chosen for peak HP alone; it will decide the 'character' of the engine and should be tailored more for the intended use. So let us know a bit more of how this will be used.
Click to expand...
The block is a 1983
 
I think you're on the right track. The 1.88/1.60 valves in the 302 heads work well, especially if your head shop does a nice deep 70 degree bowl cut and you follow up with a basic blend and gasket match port job. Nothing cosmic, in fact Mopar sold this exact setup over the counter in the early 90's. A 30 degree back cut on the intakes help.

So long as you have a halfway decent exhaust system you should end up with an honest 300 hp at the wheels.
 
C130 Chief said:
I think you're on the right track. The 1.88/1.60 valves in the 302 heads work well, especially if your head shop does a nice deep 70 degree bowl cut and you follow up with a basic blend and gasket match port job. Nothing cosmic, in fact Mopar sold this exact setup over the counter in the early 90's. A 30 degree back cut on the intakes help.

So long as you have a halfway decent exhaust system you should end up with an honest 300 hp at the wheels.
Click to expand...
Exhaust will be long tube hookers reduced to 2.5 and a pypes violator 2.5 inch x pipe system with factory style tips
 
C130 Chief said:
I think you're on the right track. The 1.88/1.60 valves in the 302 heads work well, especially if your head shop does a nice deep 70 degree bowl cut and you follow up with a basic blend and gasket match port job. Nothing cosmic, in fact Mopar sold this exact setup over the counter in the early 90's. A 30 degree back cut on the intakes help.

So long as you have a halfway decent exhaust system you should end up with an honest 300 hp at the wheels.
Click to expand...
Would the compression be too high for regular pump gas with the KB pistons or should I go with a stock style flat top and use a he268 instead of the xe268
 
Where's that 400 horse 318 link? Do most of it and you have 300+.
 
69dart340hemiorange said:
Would the compression be too high for regular pump gas with the KB pistons or should I go with a stock style flat top and use a he268 instead of the xe268
Click to expand...
I should rephrase that and put it this way will the anywhere from 9.5-10.5 compression ratio be OK for regular pump gas and will that be too much compression for that cam
 
With good gears (4.10) and a GOOD driver with slicks and hookin up GOOD, in a LIGHT car, that beeotch could see 12.90s. Das a fact.
 
69dart340hemiorange said:
I should rephrase that and put it this way will the anywhere from 9.5-10.5 compression ratio be OK for regular pump gas and will that be too much compression for that cam
Click to expand...
Because no one can say exactly what the compression wil be with the op's combination (exactly) It needs to be measured.
 
69dart340hemiorange said:
When I was looking at those KB pistons on average with the 302 casting head the compression is around 9.6-1
Click to expand...
I have dome pistols in my 273 and I measured 9.6/1 static compression.302 heads are dangeriously close to the 273 heads I have. (Port size, flow and valve size.) Both cylinder head designs are a very efficient combustion chamber and I have no engine detonation issues at that ratio. I used the thin composite head gaskets. You can look through my build thread. The link is below.
 
You must log in or register to reply here.
-

Back
Top