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#1 |
Senior Member
![]() Join Date: Apr 2001
Location: Alexandria, MN
Posts: 1,462
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So close but so far away.... ALMOST ready to fire our 250 inline
Havent posted much in the way of builds lately, but figured id post some pics of the engine some of my students and i did as part of the advanced engines class i teach. Its a 250 bored .030, flat top forged TRW L2314 pistons, Tom Lowes HYTORK cam, heavily ported and with lumps and 1.94/1.60 valves all done here at the school. This is destinted for wifeys 68 stepper here in a few weeks. Almost got this thing ready to fire for the kids tomorrow morning as it is our seniors' last day, but still missing a few things and a few wrong parts...ugh... But figured I'd throw some pics up for everybody before we hung more wires and hoses on it.... Also one of my seniors asked to restore the Merc valve and side covers for me...Did an awesome job, makes those bad days not so bad when they wow a person like that...very proud for sure! Here are the pics....
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63 C20 2WD, 230/SM420/4.11 73K 68 C30 dump truck, 327,SM425,4.56 66K original 68 C10 2WD SWB Stepper, 250/3-tree/3.73 66K.... Wifes 68 Buick Skylark Custom Conv., 350/TH400/2.56 In our family since '79 69 GMC 1500 SWB 2WD, 350/TH350/3.73 posi... 70 K10 SWB 4X4 4-sp,ps, pb, tilt, buckets, console, sliding back window (Need AC parts) WIP 72 Chevy K20 4x4 350/350/205/4.56 donor 72 Vette 350/M21/3.70 posi, triple black and super fast 84 Olds Cutlass Brougham 350/2004r/4.11 was Dad's |
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#2 |
Registered User
![]() Join Date: Jun 2012
Location: springfield mo
Posts: 3,075
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
Congrats! Looks very nice
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United States Marine Corps 2000-2011 Iraq and Afghanistan veteran Just living life now and enjoying it and my wife, daughter and son ![]() |
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#3 |
Registered User
Join Date: Oct 2007
Location: Spanaway
Posts: 8,451
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
Nice! wanna trade?
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Mike. Swamp Rat build thread : http://67-72chevytrucks.com/vboard/s...d.php?t=595019 72 3/4T 4X4 4" BDS Lift 33" BFG's |
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#4 | |
Registered User
Join Date: Jun 2014
Location: Glendale, Arizna
Posts: 1,642
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
Quote:
Is that a stock or high performance exhaust manifold? Possibly a Clifford intake with a small 4bbl in the future? I does not appear to be an integral head so maybe? That senior did an awesome job on the covers! ![]() |
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#5 |
Six in a row makes it go...
![]() Join Date: Mar 2009
Location: Vacationland: Maine
Posts: 1,346
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
Man - those Merc pieces are nice. How hard are they to find? Do they bolt right on?
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67 C20 long step resto: http://67-72chevytrucks.com/vboard/s...d.php?t=342086 66 C10 long step build: http://67-72chevytrucks.com/vboard/s...=1#post3814790 CT to Alaska in a 67 C10: http://67-72chevytrucks.com/vboard/s...d.php?t=399224 “The height of sophistication is simplicity." - Clare Boothe Luce |
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#6 |
blood type; Retumbo
Join Date: Jan 2004
Location: next to my reloading bench
Posts: 10,269
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
Wow Mike, those covers really make it look good.
A one lunger has got to choke the life right out of that thing. Now, where's that web page showing blowers for inline 6's? Yeah, 5 psi. boost with multi-port injection and CD ignition. That'll do it right. You don't mind eating mac-n-cheese and raman noodles for 6 months do you?
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Man rule #77...if you own a 67 stepside with a caddy 472 you will never be in danger of loosing you man card |
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#7 |
Registered User
Join Date: Oct 2014
Location: somewhere . . .
Posts: 961
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
liking the colour combo along w/ the detail(s) to it
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dont want to hear excuses, i want to hear solution(s) |
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#8 |
Rusty Nuts
Join Date: Sep 2008
Location: Clever Missouri
Posts: 1,338
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
Very nice!
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(Clever Missouri) Southwest Larry Mr Chevrolet My Build, The Marathon Truck http://67-72chevytrucks.com/vboard/s...d.php?t=604414 |
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#9 |
Keepin an eye out
Join Date: Feb 2003
Location: So.Cal
Posts: 3,921
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
Cool/
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1970 Chevy C10 SWB 5.3 1996 Toyota Tacoma SR5 4x4 2007 Vespa GTS 250 Scooter ZIP 91351 |
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#10 |
Registered User
Join Date: Jan 2015
Location: Ventura, CA
Posts: 818
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
That motor looks really good. That engine compartment will look clean with that in there.
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..................... ____ .........________//__{\_____ ,,,,,,,/__(O)___//___/__(O)_/ 1970 C20 -_--_--_- ______ _--_--_- /___|__\____ -_--_-_ |_(0)|__|_(0)] 1972 K5 |
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#11 |
Hittin E-Z Street on Mud Tires
![]() Join Date: Nov 2004
Location: Greenville, SC
Posts: 23,090
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
No joke, one of my greatest regrets in owning my truck the past 18 years is pulling the butter smooth, nothing wrong with it, 250 for a 350 about 12 years ago. I should have just put a T5 behind it....
Beautiful looking motor. One of the best GM ever produced. Thank you for teaching kids to do more than play with their phone.
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Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride ![]() American Born, Country by the Grace of God ![]() 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications! |
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#12 |
Senior Member
![]() Join Date: Jul 2000
Location: North Texas
Posts: 3,490
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
Gotta love the simplicity of a pre-smog 250.
Which transmission will be in the 68?
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Mike 1969 C10 LWB -- owned for 35 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then! |
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#13 |
Registered User
Join Date: Oct 2014
Location: Mesa AZ (Near Phoenix)
Posts: 2,302
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
That looks amazing.
That thing will run like stink.
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"Life is too short to drive a boring vehicle". Later, Wayne ![]() |
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#14 |
Registered User
Join Date: May 2014
Location: Mobile, AL
Posts: 422
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Just my style.........I mean just my style if I wasn't incredibly broke lol. That's about to change though, just got my degree! Seriously though, your motor reminds me of mine, just better!
Last edited by Custom/Ten; 05-21-2015 at 11:57 AM. |
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#15 |
Registered User
Join Date: Mar 2013
Location: Anaheim Hills, CA
Posts: 323
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
I assume he is talking about a cam shaft with larger lobes?
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1971 Cheyenne Big Block Longhorn |
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#16 |
Registered User
Join Date: May 2014
Location: Mobile, AL
Posts: 422
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
No it's actually a lump that goes in the head. 250 guys are always talking about installing lumps. Supposed to be a great upgrade. Changes air/fuel flow.
Last edited by Custom/Ten; 05-21-2015 at 12:58 PM. |
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#17 |
Registered User
Join Date: Jul 2010
Location: Willingboro, NJ
Posts: 489
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
"Lump Port" is actually a modification of cylinder head. A wedge is installed into the intake passages, kind of looks like the top of an airplane wing, or a lump, hence the name. Because the 250 and 292 (and I assume 230's as well) each cylinder shares the intake port on the head and manifold the air velocity is decreased over all due to the large port in relationship to volume of air each cylinder will take. Only one valve opens at a time so the speed at fuel/air mix is in drawn in is on the slow side. The lump is supposed to increase the air velocity and mixture efficiency with in the head prior to the intake valve. The stove bolt guys have touted the lump port modification has the way to go. Want to try out a lump port on one of my spare cylinder heads.
Paul
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Retired USAF - No rockets, no mortars, no bad guys shooting...No stress!!! ![]() My Build Thread: Project 72' Green http://67-72chevytrucks.com/vboard/s...d.php?t=587932 |
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#18 |
Registered User
Join Date: Apr 2010
Location: So Cal
Posts: 1,437
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
tkeduk8r, I have a question about your PCV system. The PCV valve with vacuum line is top center. I can't see where the fresh air intake is for the system.
An internet search for "MerCruiser 250" produces plenty of valve covers and complete engines. Most are on Ebay. I can't see on any of those pictures either, what provision is made for PCV air intake. Lump ports on the inline head, involves cutting out the head bolt boss and raising the intake port floor. Each of the three intake ports feed two valves. The boss for the head bolt provides restriction and the area inside the port is large and causes the velocity of the air/fuel to slow just before the valves. Removing the boss increases the port volume even more. Adding a large lump to the port floor with brazing, epoxy or an aluminum insert, reduces the volume and directs the flow toward the valve pocket. There are a couple of different aluminum inserts, but they all involve removing the boss, installing a short hex head bolt and plugging the old hole on top. Sorry, ironduke, I didn't know you had posted as I was a little slow. These images should help.
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'67 GMC 2500, 292, 4spd, AC |
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#19 |
Registered User
Join Date: May 2014
Location: Mobile, AL
Posts: 422
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Good info from these guys, I also saw some cool vids on YouTube with guys installing lumps!
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#20 | |
Registered User
Join Date: Mar 2013
Location: Anaheim Hills, CA
Posts: 323
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
Quote:
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1971 Cheyenne Big Block Longhorn |
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#21 |
Registered User
Join Date: Jul 2010
Location: Willingboro, NJ
Posts: 489
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
"The boss for the head bolt provides restriction and the area inside the port is large and causes the velocity of the air/fuel to slow just before the valves. Removing the boss increases the port volume even more."
Thanks for the correction.
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Retired USAF - No rockets, no mortars, no bad guys shooting...No stress!!! ![]() My Build Thread: Project 72' Green http://67-72chevytrucks.com/vboard/s...d.php?t=587932 |
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#22 |
Senior Member
![]() Join Date: Apr 2001
Location: Alexandria, MN
Posts: 1,462
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
Thanks guys... Was at school that night till about 11.... Didn't know the flu was waiting until about 230 am and have been home sick the past two days...gonna be missing graduation tonight too.... Oh well...
Anyway... The lump port mod is due to the fact that a head bolt passes right through the three siamezed (?) Intake ports. Basically you cut and machine the bolt boss out of the head and insert a aluminum "lump" that directs the intake charge more efficiently to the valves.. Very cool and disgustingly common sense.... The exhaust manifold is a stock c60 with a larger 2.5 inch outlet.... Found out the hard way that neither my Clifford intake nor my factory power steering brackets are compatible with it ![]()
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63 C20 2WD, 230/SM420/4.11 73K 68 C30 dump truck, 327,SM425,4.56 66K original 68 C10 2WD SWB Stepper, 250/3-tree/3.73 66K.... Wifes 68 Buick Skylark Custom Conv., 350/TH400/2.56 In our family since '79 69 GMC 1500 SWB 2WD, 350/TH350/3.73 posi... 70 K10 SWB 4X4 4-sp,ps, pb, tilt, buckets, console, sliding back window (Need AC parts) WIP 72 Chevy K20 4x4 350/350/205/4.56 donor 72 Vette 350/M21/3.70 posi, triple black and super fast 84 Olds Cutlass Brougham 350/2004r/4.11 was Dad's |
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#23 |
Senior Member
![]() Join Date: Apr 2001
Location: Alexandria, MN
Posts: 1,462
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
Oh... And yes the merc covers are bolt on... I had to use to use two gaskets to clear the ARP head studs...as far as the pcv system goes there is only one port and it had a hollowed out pcv valve in there when I got the covers... So I don't know how "it should" go....I'll have to figure out how I want to make it work on the truck yet...may have to drill into cover for connection to air cleaner yet well see...
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63 C20 2WD, 230/SM420/4.11 73K 68 C30 dump truck, 327,SM425,4.56 66K original 68 C10 2WD SWB Stepper, 250/3-tree/3.73 66K.... Wifes 68 Buick Skylark Custom Conv., 350/TH400/2.56 In our family since '79 69 GMC 1500 SWB 2WD, 350/TH350/3.73 posi... 70 K10 SWB 4X4 4-sp,ps, pb, tilt, buckets, console, sliding back window (Need AC parts) WIP 72 Chevy K20 4x4 350/350/205/4.56 donor 72 Vette 350/M21/3.70 posi, triple black and super fast 84 Olds Cutlass Brougham 350/2004r/4.11 was Dad's |
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#24 |
Senior Member
![]() Join Date: Apr 2001
Location: Alexandria, MN
Posts: 1,462
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
And it'll have a 4speed OD MY6 trans out of an 84 c10 behind it with a 3.73 gear turning 31 inch tires...
--Mike
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63 C20 2WD, 230/SM420/4.11 73K 68 C30 dump truck, 327,SM425,4.56 66K original 68 C10 2WD SWB Stepper, 250/3-tree/3.73 66K.... Wifes 68 Buick Skylark Custom Conv., 350/TH400/2.56 In our family since '79 69 GMC 1500 SWB 2WD, 350/TH350/3.73 posi... 70 K10 SWB 4X4 4-sp,ps, pb, tilt, buckets, console, sliding back window (Need AC parts) WIP 72 Chevy K20 4x4 350/350/205/4.56 donor 72 Vette 350/M21/3.70 posi, triple black and super fast 84 Olds Cutlass Brougham 350/2004r/4.11 was Dad's |
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#25 |
Account Suspended
![]() Join Date: Aug 2005
Location: Southern UT
Posts: 906
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Re: So close but so far away.... ALMOST ready to fire our 250 inline
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