The 151 is worthy I think?

Moderator: Moderators

Postby rickswagon » Tue Nov 14, 2006 11:32 pm

www.sallee-chevrolet.com/frame.html?/Cy ... s/4-6V.htm

try this site have not called yet but they list stuff for the iron duke
User avatar
rickswagon
 
Posts: 294
Joined: Sun Aug 13, 2006 1:53 am
Location: Elizabethtown Nc

1978 Chevrolet Monza Sport Hatchback


Postby HI WINDING MONZA » Sat Dec 02, 2006 11:41 pm

I'm getting rid of my 151 crossflow engine stuff soon, cant compete in the heat, best I could get out of it was 16.93 in 1/4 with .030 cast stock pistons, . hydrlalic cam . 543 lift with clifford springs, modified jeep Headman Header, mild ported head and intake, modified varijet carb , Crane hardened pushrods and locking rocker nuts, efan, efuel pump, 4.56 gears, slicks, Ram pressureplate, Lightened flywheel ,AMC Eagle 4x4 2.5 Pontiac clutch Disc, Etc. Etc. About 150 HP. Never got around to putting a solid cam or a modified head with Olds 403 Intakes and BBC springs I still have . Would buzz up to 7300rpm ( no need for a 4 bbl) but the cam only made power to 5600. ( Biggest hydralic they make) I've spun a #4 rod once and shattered a # 4 rod this summer. Rods are the weakest link in these motors, spend your money there. ( custom) For every day drivers, just get the stockers shotpeend and beam polished because I've broke a few stockers in other cars with a 2.5. That Kansas place is the best, ( big $$$$$$$$$$) I met a guy in Syracuse that had one of those blocks with a SBC head , custom intake with webers, that ran low 8's in a rail! ( All Motor) And for some strange reason , race leaded fuel gave me a second quicker in the 1/4. The motors hate outside heat and humidity, makes them run a lot slower. ( they love 70* best) I'm like you two above , I love to wind them out, Thats where I got the nickname at the track. Ive raced this motor on and off for the last 16 years and finished in 4th place at ESTA dragstrip in 1998 going against V8s with autos. Doug In Az 8)
My Old Cadillac Powered Monza Still Lives...........now on its 5th owner!..........Somewhere ?

The 90's just keep rollin' along........
1990 Chevrolet Silverado Regular Cab Long Bed 350 TBI V8 700R4 109k miles
1992 Pontiac Sunbird Coupe 2.0 OHC MPFI I4 TH125C 150k miles
User avatar
HI WINDING MONZA
 
Posts: 3080
Joined: Thu Jun 29, 2006 7:37 pm
Location: Salinas, Puerto Rico

Postby HI WINDING MONZA » Sun Dec 03, 2006 12:13 am

And I forgot to mention , most manufactors have phased out the 151 stuff, not many left even making parts. Doug in AZ 8)
My Old Cadillac Powered Monza Still Lives...........now on its 5th owner!..........Somewhere ?

The 90's just keep rollin' along........
1990 Chevrolet Silverado Regular Cab Long Bed 350 TBI V8 700R4 109k miles
1992 Pontiac Sunbird Coupe 2.0 OHC MPFI I4 TH125C 150k miles
User avatar
HI WINDING MONZA
 
Posts: 3080
Joined: Thu Jun 29, 2006 7:37 pm
Location: Salinas, Puerto Rico

Pontiac Super Duty 151 on ebay

Postby res0o7eb » Sat Dec 09, 2006 6:23 pm

There's a Pontiac Super Duty 151 Race engine on ebay.

I borrowed the blurry pictures and posted them here for permanent viewing and drooling.

--Tom
Attachments
a03c_1.JPG
a03c_1.JPG (23.42 KiB) Viewed 2273 times
b9eb_1.JPG
b9eb_1.JPG (22.54 KiB) Viewed 2273 times
a921_1.JPG
a921_1.JPG (24.6 KiB) Viewed 2273 times
a49c_1.JPG
a49c_1.JPG (21.12 KiB) Viewed 2273 times
User avatar
res0o7eb
 
Posts: 3783
Joined: Wed Jun 28, 2006 10:53 pm
Location: Near Seattle, WA

1977 Pontiac Sunbird Hatchback

Postby NixVegaGT » Wed Dec 20, 2006 2:29 pm

That's great input, Doug. I've heard good things about this engine in the past. Especially when I was hooked up with the turbo Mopar crowd. They always respected the Duke. I heard it was a pretty tough engine.

I'm really intrigued by this SBC head idea... That might be something to seriously consider. You could get one of those shallow angle heads. Like one of those 18º jobbies. They show great flow numbers... Also a couple side draft webbers seems like a good combo. I guess it comes down to the cam then.

I could suggest a really good book for home porting if you're interested:
http://www.amazon.com/Practical-Gas-Flo ... F8&s=books


I read an article about a bunch of guys swapping a DOHC head on these too. That was back in '87 though so I hope that doesn't send anyone down a dead end.

I like the idea of working on your Duke instead of swapping in a SBC mostly because that swap is so over done. I'm not adverse to it, it's just a little too common for my taste. That said, it does take a big commitment to working out the smallest details. You can't really make easy power NA. You've got to get the power from every place you can get it.

OK a friend of mine from v8buick.com would bitchslap me if I didn't get a turbo pitch in here. You can definately make some power with a turbo. Even with a blow through carb style. Upgrade the rods and pistons. From my research on pistons for the Wildcat 355 project you could fit a couple different pistons in here: Ford 289 pistons are the right compression height +0.015 and you could have the pin holes honed to fit chevy pins. You already know the Pontiac 301 but finding the right pistons for a turbo application would be a nightmare. The did make a 301 turbo. A friend of mine is trying to build one now. Really tough to find pistons. The Chevy 4.3L V6 pistons would work. They are similar to the SBC but have the shallower compression height you need.

For rods... What are the dims for the Duke's rods? I'm betting we could find an equivolent.

Here's a link to some Comp Cams numbers:
http://www.compcams.com/catalog/202_203.html

I also found out that Super Duty you've got in the pic is supposed to be good for 200hp!


Cool idea guys. Keep up the thread. Let me know where you go with it.
- Nic '73 Vega GT "DogBoxx" Batwing LS1
http://www.cardomain.com/ride/2357894
User avatar
NixVegaGT
 
Posts: 2196
Joined: Sat Nov 11, 2006 2:24 am
Location: Minnesota

1973 Chevrolet Vega GT

Postby HI WINDING MONZA » Wed Dec 20, 2006 9:35 pm

Nic, If I was still back East, I would keep runnin the Duke.............But here with racetime Temps hovering around 100*, It makes no sence to compete with small cubes and lose...............its big blocks that love heat...............I've seen that even back East. The 440 Monaco ran consistant low 15's all last season ................. It is a piece of crap and people were amazed that the big boat could fly that fast and win big! ( so good that the rookie driver finished in 4th place) As for the rods on the 151, I know they are 6 " long with a 2'' journal , and don't know what would interchange, I think a custom aluminum rod would do nicely. As for your 301 Turbo pistons ( which are the same size as 151 crossflow pistons ) I heard that they are unavailable. ( forged) just the cast are available. I think custom again on that...........Doug in Az 8) Ps, I'm swapping in a Gm Big Block, not a SBC , I agree with you on that , too many SBC's! :( sorry guys)
My Old Cadillac Powered Monza Still Lives...........now on its 5th owner!..........Somewhere ?

The 90's just keep rollin' along........
1990 Chevrolet Silverado Regular Cab Long Bed 350 TBI V8 700R4 109k miles
1992 Pontiac Sunbird Coupe 2.0 OHC MPFI I4 TH125C 150k miles
User avatar
HI WINDING MONZA
 
Posts: 3080
Joined: Thu Jun 29, 2006 7:37 pm
Location: Salinas, Puerto Rico

Postby HI WINDING MONZA » Wed Dec 20, 2006 10:34 pm

I forgot to add that the Super Duty Four ( like the one on Ebay now) was capiable of 350-375 Hp normally aspirated. Pontiac made 2 different blocks and 4 different heads. That Kansas place will redrill a 151 block to accept any head ( Not just Gm) you want. Doug In AZ 8)
My Old Cadillac Powered Monza Still Lives...........now on its 5th owner!..........Somewhere ?

The 90's just keep rollin' along........
1990 Chevrolet Silverado Regular Cab Long Bed 350 TBI V8 700R4 109k miles
1992 Pontiac Sunbird Coupe 2.0 OHC MPFI I4 TH125C 150k miles
User avatar
HI WINDING MONZA
 
Posts: 3080
Joined: Thu Jun 29, 2006 7:37 pm
Location: Salinas, Puerto Rico

Postby NixVegaGT » Thu Dec 21, 2006 10:12 am

True enough, Doug, about running a 4. It's a bit tougher. Don't get me wrong it's a fun challenge.

The turbo car I built made around 260hp at the wheels and it broke everything all the time to make that. I was constantly fixing something. Now that was a front driver with a gearbox made of ice cream of course. I broke axles, motormounts, and exhaust flanges, suspension parts, turbos, and finally the gearbox. The engine I built was awesome! but it was really hard on everything else. That might not be as big an issue with the H though. You'd know better than me.

It handled like a M*therF*cker though! Damn it was fun to drive and a lot of that I can attribute to weight distribution. That's where a heavy engine will make a big difference. BUT it all depends on application! I really wanted a road car. A big engine will get you down the track in a hurry though.

She liked to run hot too. So your point about track temps is a good one.

431... Is that an overbore 427? BTW that color really works on your car. Did you paint a bumble bee badge on your car? I might be mixing you up with another guy. It's a cool looking car.
- Nic '73 Vega GT "DogBoxx" Batwing LS1
http://www.cardomain.com/ride/2357894
User avatar
NixVegaGT
 
Posts: 2196
Joined: Sat Nov 11, 2006 2:24 am
Location: Minnesota

1973 Chevrolet Vega GT

Postby HI WINDING MONZA » Thu Dec 21, 2006 6:48 pm

You're REAL close on that Guess Nic, but no cigar! :lol: The Decal is SKI DOO, And the stripe is like a reverse early Camaro- BBody Mopar combination. We painted the Monaco with a black " Coast Guard" type stripe on the rear quarters with "440 Sport Coupe" lettering body color " Citron Gold " in the middle which is the factory color for the 70 Monaco. Doug in AZ 8)
My Old Cadillac Powered Monza Still Lives...........now on its 5th owner!..........Somewhere ?

The 90's just keep rollin' along........
1990 Chevrolet Silverado Regular Cab Long Bed 350 TBI V8 700R4 109k miles
1992 Pontiac Sunbird Coupe 2.0 OHC MPFI I4 TH125C 150k miles
User avatar
HI WINDING MONZA
 
Posts: 3080
Joined: Thu Jun 29, 2006 7:37 pm
Location: Salinas, Puerto Rico

Postby res0o7eb » Wed Dec 27, 2006 2:56 pm

Found this 'encouraging' link in the archives.
http://forums.h-body.org/viewtopic.php?t=17515
Last edited by res0o7eb on Fri Jan 18, 2008 10:34 pm, edited 1 time in total.
User avatar
res0o7eb
 
Posts: 3783
Joined: Wed Jun 28, 2006 10:53 pm
Location: Near Seattle, WA

1977 Pontiac Sunbird Hatchback

Postby HI WINDING MONZA » Wed Dec 27, 2006 10:16 pm

Tom , you are a determined little 151 bugger , aren't you! :lol: :lol: Doug in Az 8
User avatar
HI WINDING MONZA
 
Posts: 3080
Joined: Thu Jun 29, 2006 7:37 pm
Location: Salinas, Puerto Rico

Postby IronDukeVega » Fri Dec 29, 2006 4:33 pm

Folks,

I was searching the web for info on the Edelbrock Pontiac HD 151 valvecover and found this thread - interesting. The valvecover, by the way, is no longer available.

I have a 1971 Vega with a 1978 Pontiac 151 non-crossflow that came out of a '78 Monza. I took the engine, Saginaw 4 sp (better ratios than the Vega version) and the front brake system (vented rotors, much bigger calipers and pads - and far better braking). This engine is probably the easiest engine sawp for the Vega (and the engine they should have used in the first place ...Chevy 153 derivitive). I thought I had the better engine than the stock Vega motor for modification but was wrong - there were far more aftermarker parts for the 2.3 Vega than the non-crossflow Pontiac. The pictures above brought back memories. I had the Offy dual port 4 bbl manifold with Holley 390 and later the dual Weber 45 DCOE9 side draft carbs at different times (this was back in the late 70s).

For the Vega motor, the 4 bbl dual port manifold was an interesting idea, but it did not work well. The primary side of the manifold was at the bottom which forced the majority of intake flow to move along the floor of the intake port - the worst part of the Vega intake port design (a sharp radius that angled back on itself. Later Vegas had a raised floor with longer radius). The manifold would probably have worked much better if the carb was rotated so that the primaries were on the secondary side of the manifold and the flow was on the top deck. This would in effect lead to a long, easy flow curve into the valve area. Never tried it though. The Webers looked awesome, but they never tuned right. Throttle response was unbelievable, but the intake suffered from low intake flow inertia at normal rpms and an inibility to sync the carbs effectively given the piss-poor IECO supplied linkage - turn your headlights on at idle and the rpms would drop from 1000 to 500. I still have the manifold but sold the carbs. This engine had a perf. cam and Hedman headers (great collector design). In the end, the stock Vega manifold with a Holley 350 cfm 2bbl worked the best. With impossibly odd engine problems (loooong story), I went with the 151 in 1984 when my wife's 1978 Monza got wrecked.

For the 151, I made the following modifications on a rebuilt motor (.030 over): decked head a total of .070 and the block .005 for a likely 9.75+:1 compression, perf. cam with .493 lift and 210 degrees at .050, HiPo valve springs, bronze valve guides, bigger intake valves (1.84 v. 1.74), ported head, Crane roller rockers, high volume oil pump, modified stock intake manifold with Holley 350 cfm 2bbl, custom 2.25 headpipe and 2.25 exhaust, HiPo cat, 2.5" Dynomax muffler and tailpipe in the stock path. I'm figuring close to 140+ hp at 5,200 rpm. My only issue with these modifications is that the engine has been very sensitive to lifter loads from increased lift and higher tension valve springs. My first cam was .554 lift and with valve geometry problems the lifters would suddenly bleed down at 4,000 rpm, making a sound like the engine was beeing hammered to death. Ultimately, I solved the problem by going to a different cam with less lift, using Wolverene lifters with a bigger oil feed hole, installing a high volume oil pump, and getting the valve train geometry set correctly. The geometry could only be checked once I installed the roller rockers since I now had an exact pivit point to check the rocker radius movement against. Still, the valve guides suffer from accelerated wear. The greater the valve-to-guide clearance the greater the engine vibration. Believe it or not, I now know that this type of vibration causes the Holley accelerator pump to pump fuel on its own starting at around 3,000 rpm.

What does it all mean in a 2,400 pound car with 3.36 gears? I'm guessing 0-60 in 8 and the 1/4 mile in 16. Problem is I need an overdrive trans since 3,500 rpm at 65 mph means only 20 mpg (my '06 V8 Tundra does better). The Tremec TKO 500 is my goal, but at $2,000 it's likely a ways off. The engine sounds great but is rough, causing the Hurst linkage to buzz badly at high rpm.

Back to the start of this all - the valve cover. In order to accomodate the roller rockers, I had to push out the front and back ends of the stock valve cover and weld in new metal - ugly!. The valve cover pictured above looks like it would actually fit on the non-crossflow but now looks to be an ebay item at best. One word of advice. If you modify your valve cover or have one that lets oil directly reach the PCV valve, when the car sits for about a day, an oil drop will form at the inlet of the PCV valve and hang there. When you start the car, that oil will be sucked into the manifold and cause a nice puff of blue smoke out the tailpipe. Drove me nuts thinking I had valve seal problems. Once I eliminated the space in the modified PCV baffle under the valve cover necessary to clear the rockers, oil no longer was slung against the PCV valve - and no more puff of blue smoke at start-up!

I'd like to post some pics of my car. Just about finished a restoration. It's now Cranberry red with silver fender stripes, 13" Cragar rims, fiberglass lift-off hood, custom rear spoiler, lowered suspension, 1975 Vega and Monza interior. Almost no other Vegas here on the roads around San Francisco.
IronDukeVega
 
Posts: 3
Joined: Fri Dec 29, 2006 4:28 am

1971 Chevrolet Vega Hatchback

Postby res0o7eb » Fri Dec 29, 2006 4:54 pm

IronDukeVega,

Welcome to this site.
Thank you for sharing your experience with the 151 (and the 140). Some good info there. Hope to see more from you.

I thought the valve cover shown above was a Pontiac SD part. Is that not correct?

I'm sure I speak for many in that we would like to see your Vega added to the Garage - finished or not. Sounds like you have a nice ride.
Last edited by res0o7eb on Sun Nov 04, 2007 11:39 pm, edited 1 time in total.
User avatar
res0o7eb
 
Posts: 3783
Joined: Wed Jun 28, 2006 10:53 pm
Location: Near Seattle, WA

1977 Pontiac Sunbird Hatchback

Postby IronDukeVega » Sun Dec 31, 2006 3:35 pm

Folks,

Great to see so much info and interest here on the now obscure H-body. I'm gradually putting info on my ride in the Garage. Still hoping to get hold of the Edelbrock SD valve cover. I see it works on a stock crossflow motor as shown with the link below, but in a worst-case situation, I'm sure there's a way to make one fit a non-crossflow with custom fabrication if necessary. "If there's a will there's a way" seems to characterize much of what drives us to keep H-bodies going anyway.


link to website about Fieros with SD valvecover:
http://www.fiero.nl/cgi-bin/fiero/showT ... =printable
IronDukeVega
 
Posts: 3
Joined: Fri Dec 29, 2006 4:28 am

1971 Chevrolet Vega Hatchback

Postby IronDukeVega » Tue Jan 09, 2007 12:36 am

Value cover update:

After finding more pictures of the SD valvecover, I was able to determine that it will not fit on the non-crossflow head. I had contacted Edelbrock about the availability and they said it was discontinued 2 years ago (2004?). I also asked why it was still listed when it had not been available for all that time, and the response was essentially that the continued listing was valid because it was qualified with "while supplies last." I would therefore interpret anything footnoted with that comment as likely "no longer available." At least it's a nice reminder of what was once produced - so you can keep an eye out for one on eBay.
IronDukeVega
 
Posts: 3
Joined: Fri Dec 29, 2006 4:28 am

1971 Chevrolet Vega Hatchback

PreviousNext

Return to Engine Tech

Who is online

Users browsing this forum: No registered users and 1 guest