talking heads - Pirate4x4.Com : 4x4 and Off-Road Forum

Chief yelling alot · 01-20-2004, 11:21 PM

no not the band

in school in ~2 weeks we will be doing a head re & re so I thought why dont I grab a pare of 345 heads from a wrecker I go to (about $10.00) and do them for my scout (so I have a good set handy if I need them)

hears the question

how much should I mill off to compensate for the new style gaskets and maybe a small + in comprssion. with out altering the intake mating surface.

also any info for opening up the ehaust port would be grate.

thanks

Scout Dude · 01-20-2004, 11:28 PM

about 2 inches..this will save you about 60 lbs!

Tech related: Seems to me that you could bump the compression up a huge amount on a 345 and maybe, just maybe, get some decent power vs weight out of them. What's the most that has been tried on these?

Darel · 01-21-2004, 05:00 AM

There is a guy here in MT I just talked to last week that mills his heads A LOT (can't recall an exact number, I'll ask again) and runs 9.4:1 or more in a couple of 392s he and his son built. He runs Isky custom-grind cams and says they'll put down some "decent power". He's been running this way for years so I don't see any reason why you couldn't take a pair of $10 heads and experiment.
Darel

Mechanos · 01-21-2004, 06:17 AM

I say none. Just mill the least amount necessary to true them up. Deck the block to compensate for composite gaskets. I'm not saying you can't mill the heads, I'm just saying that I would rather deck the block.

Sully · 01-21-2004, 11:03 AM

Why deck the block, instead of milling the heads?

Mechanos · 01-21-2004, 11:40 AM

Greater change in volume per .001" of material removed. .030" off of the block nets a larger volume than .030" off the heads.

scoutver5.7 · 01-21-2004, 01:21 PM

Quote:

Originally posted by Sully
Why deck the block, instead of milling the heads?

Zero deck height. Better flame propogation. Gets rid of pinging problems so common on SVs. More power.

I took .040 off my block for zero deck. Took .008 off the heads - just to true them up. Angle cut them to ensure good intake mating. Ended up at 9.3:1 with FM hypueretic (sp?) flattop pistons.

Chief, if your heads have the AIR injection bosses in the exhaust ports (not all do) grind them out and match the port to the manifold or header gasket. Blend in no more than about 3/4" - leave any more than that to experienced porters.

Chief yelling alot · 01-21-2004, 01:40 PM

well how much should I take off to compensate for the gasket?

looks like to run regular i'll keep the CR the same

there non air injection

tsm1mt · 01-21-2004, 04:03 PM

Just to compensate for the gasket? About .020 IIRC.

I decked my 392 .036" which was what it needed to hit 0-deck (with a .035 stroke and topped pistons).

Somewhere over 9:1, and it didn't seem to be a pinger..

DocDan has some great stories to tell, eh, Darel?

I have a 304 that's over 10:1..the pistons come out of the deck.. makes good power.. sure surprises the Chevy powered Jeeps..

01-20-2004, 11:21 PM	#1 (permalink)
Chief yelling alot Registered User Join Date: Oct 2001 Member # 7646 Location: New Westminster B.C. Canada Posts: 5,345	talking heads no not the band in school in ~2 weeks we will be doing a head re & re so I thought why dont I grab a pare of 345 heads from a wrecker I go to (about $10.00) and do them for my scout (so I have a good set handy if I need them) hears the question how much should I mill off to compensate for the new style gaskets and maybe a small + in comprssion. with out altering the intake mating surface. also any info for opening up the ehaust port would be grate. thanks __________________ 85 suzuki sj 410, 82 suzuki sj 410 pickup 68 IH pickup, 78 Scout II 76 Scoutt II turbo 345 propane

01-20-2004, 11:28 PM	#2 (permalink)
Scout Dude Registered User Join Date: Apr 2001 Member # 4001 Location: Citrus Heights, CA Posts: 3,986	about 2 inches..this will save you about 60 lbs! Tech related: Seems to me that you could bump the compression up a huge amount on a 345 and maybe, just maybe, get some decent power vs weight out of them. What's the most that has been tried on these? __________________ Dysfunctional Rockcrawlers

01-21-2004, 05:00 AM	#3 (permalink)
Darel Registered User Join Date: Jul 2003 Member # 21309 Location: Langhorne, PA Posts: 210	There is a guy here in MT I just talked to last week that mills his heads A LOT (can't recall an exact number, I'll ask again) and runs 9.4:1 or more in a couple of 392s he and his son built. He runs Isky custom-grind cams and says they'll put down some "decent power". He's been running this way for years so I don't see any reason why you couldn't take a pair of $10 heads and experiment. Darel __________________ Lots of IHs. Lots of other junk. No money.

01-21-2004, 06:17 AM	#4 (permalink)
Mechanos Pirate4x4 Addict! Join Date: Aug 2001 Member # 6704 Location: Roosterville, Missouri Posts: 6,986	I say none. Just mill the least amount necessary to true them up. Deck the block to compensate for composite gaskets. I'm not saying you can't mill the heads, I'm just saying that I would rather deck the block. __________________ It's IHeavy aka TORC KC0UIC -.- -.-. ----- ..- .. -.-. Nothing is foolproof to a sufficiently talented fool.

01-21-2004, 11:03 AM	#5 (permalink)
Sully Zeus of the Sluice Join Date: Jun 2002 Member # 12121 Location: Live Free or Die Posts: 4,787	Why deck the block, instead of milling the heads? __________________ Live Free or Die Why is mankind the only species that attempts to preserve the shallow end of its gene pool?

01-21-2004, 11:40 AM	#6 (permalink)
Mechanos Pirate4x4 Addict! Join Date: Aug 2001 Member # 6704 Location: Roosterville, Missouri Posts: 6,986	Greater change in volume per .001" of material removed. .030" off of the block nets a larger volume than .030" off the heads. __________________ It's IHeavy aka TORC KC0UIC -.- -.-. ----- ..- .. -.-. Nothing is foolproof to a sufficiently talented fool.

01-21-2004, 01:40 PM	#8 (permalink)
Chief yelling alot Registered User Join Date: Oct 2001 Member # 7646 Location: New Westminster B.C. Canada Posts: 5,345	well how much should I take off to compensate for the gasket? looks like to run regular i'll keep the CR the same there non air injection __________________ 85 suzuki sj 410, 82 suzuki sj 410 pickup 68 IH pickup, 78 Scout II 76 Scoutt II turbo 345 propane

01-21-2004, 04:03 PM	#9 (permalink)
tsm1mt Registered User Join Date: Oct 2000 Member # 2071 Location: Helena, MT USA Posts: 5,169	Just to compensate for the gasket? About .020 IIRC. I decked my 392 .036" which was what it needed to hit 0-deck (with a .035 stroke and topped pistons). Somewhere over 9:1, and it didn't seem to be a pinger.. DocDan has some great stories to tell, eh, Darel? I have a 304 that's over 10:1..the pistons come out of the deck.. makes good power.. sure surprises the Chevy powered Jeeps.. __________________ -Tom KE7VUX

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode