Stock Ford 351W 4bbl dyno numbers

[Galon]

Has anyone dynoed a stock 1969 Ford 351w 4 bbl motor? I'm looking for good dyno numbers on a stock 351w 4 bbl carb motor with no modifications. It was factory rated at 290hp. Is this a realistic number? For this information it should be a restoration build with no mods. Any help would be appreciated. Thanks

[PackardV8]

FWIW, the 1969 figures were still gross horsepower.

[dondon]

according to an article in 1969 by Roger Huntington a stock 351 windsor made 210 hp at 4300 rpm's

[travis]

There was an article in Hot Rod magazine in the mid ‘80’s where Jon Kaase was developing 351w packages. A bone stock 2bbl early 351w with stock replacement forged pistons (9.0 compression) and dyno headers made 211 Hp/353 tq. Adding an aluminum ford dual plane intake similar to an Edelbrock 2181/600 4bbl added like 16 Hp. Adding a good 3 angle valve job brought it up to 255 Hp/362 tq. Then a performer type cam (204/214@.050) brought it up to 291 Hp/373 tq.

I’ve built and/or owned pretty much every variation of carbed stock 351w ever made...there was nothing magical about the ‘69/‘70 years. They was all strong off idle, and ran out of steam quickly. In a ‘69 or ‘70 mustang with 3.50 gears, they was typically a low-mid 15 second car. I’d dare say that the early FI version (‘88-‘93), with the FI swapped for a 4bbl intake/carb, was slightly stronger.

Afaik, there was only 2 hft cams ever offered from the factory on almost all 351w’s (other than the Lightning trucks)...one was 195/195@.050, .416/.416 lift, 107.5 lsa, the other was 206/221@.050, .444/.453 lift, 115 lsa. All carbed versions from ‘69-‘87 got the smaller cam whether it was in a mustang or a truck. FI engines got the bigger one until they switched to a hydraulic roller in ‘94. Lightning’s got a 198/208, .416/.445, 114 lsa hydraulic flat tappet cam iirc.

The ‘69 up to around ‘75 or ‘76 had the bigger valves (1.84/1.54) and typically low to mid 60’s cc chambers. They flow better than the later year heads (except for the Lightning’s which had GT40 iron heads), but the engines was choked with a very low profile intake and pretty terrible exhaust manifolds.

[n2omike]

The ‘69 up to around ‘75 or ‘76 had the bigger valves (1.84/1.54) and typically low to mid 60’s cc chambers. They flow better than the later year heads (except for the Lightning’s which had GT40 iron heads), but the engines was choked with a very low profile intake and pretty terrible exhaust manifolds.

The 1969 and 1970 heads were the best two years. They had the bigger valves, and also smaller chambers. After 1970, the chambers got huge. The C9OE and D0OE heads were the ones to have. Of course, everything aftermarket (including the GT40) totally eclipses them every way...

[travis]

The ‘69 up to around ‘75 or ‘76 had the bigger valves (1.84/1.54) and typically low to mid 60’s cc chambers. They flow better than the later year heads (except for the Lightning’s which had GT40 iron heads), but the engines was choked with a very low profile intake and pretty terrible exhaust manifolds.

The 1969 and 1970 heads were the best two years. They had the bigger valves, and also smaller chambers. After 1970, the chambers got huge. The C9OE and D0OE heads were the ones to have. Of course, everything aftermarket (including the GT40) totally eclipses them every way...

There is a grey area around ‘75-‘76 where some may have had 69cc chambers, but every ‘71-‘76 head I’ve seen had a 64-65cc chamber. 1977-ish they went to the smaller 1.78/1.46 valves and 69-70cc chambers, and pedestal rockers.

I think ultimately all the pre-‘78 heads have about the same potential in ported form. The D0OE’s I have here that I need to finish flow 229/150 (no pipe) with undercut 1.94/1.50 valves.

[frnkeore]

Since this has gotten way OT, I have a quick question.

Are the 302, D0OE heads any different in the port area, than the 351W's? I know the valves are the smaller 1.78 x 1.46 and the chambers are a little smaller (58cc) but, what about the ports? I have a pair, in my parts bin.

[Galon]

The reason for the initial question was because of a 351w I have dynoed with lower what estimated numbers. The numbers aren't terrible but I was expecting at least the 290hp the factory claimed. Peak hp was 281 at 4600 rpm and peak torque was 369 at 3300-3500 rpm. Air fuel could be a little leaner but I wouldn't expect another 10hp. Air fuel was high 11 to 12. Timing was 34-37 degrees with little effect. The intake is a edelbrock performer rpm. Compression ratio is 10. The camshaft is a Comp Cam .433 -.447 lift with 206-212 dur. @.050 106 centerline and 110 lobe separation. Carb is a modified Holley 750. Headers are 1 3/4 dia. 28" primary length and a 3" collector into turbo mufflers. My original thoughts were the engine should be around 300hp with a better manifold and camshaft. I have run numerous engine simulations and they all look even worse than my numbers from the actual dyno test although the peak torque and peak hp rpm numbers are at the same rpm the dyno shows. This is why I asked for original numbers from a stock restoration build to see if the factory numbers were realistic. Although the engine sounds great the numbers are disappointing. A bit confused. Thank you for all of your recent responses.

[travis]

Since this has gotten way OT, I have a quick question.

Are the 302, D0OE heads any different in the port area, than the 351W's? I know the valves are the smaller 1.78 x 1.46 and the chambers are a little smaller (58cc) but, what about the ports? I have a pair, in my parts bin.

Yes, the ports are smaller

[travis]

The reason for the initial question was because of a 351w I have dynoed with lower what estimated numbers. The numbers aren't terrible but I was expecting at least the 290hp the factory claimed. Peak hp was 281 at 4600 rpm and peak torque was 369 at 3300-3500 rpm. Air fuel could be a little leaner but I wouldn't expect another 10hp. Air fuel was high 11 to 12. Timing was 34-37 degrees with little effect. The intake is a edelbrock performer rpm. Compression ratio is 10. The camshaft is a Comp Cam .433 -.447 lift with 206-212 dur. @.050 106 centerline and 110 lobe separation. Carb is a modified Holley 750. Headers are 1 3/4 dia. 28" primary length and a 3" collector into turbo mufflers. My original thoughts were the engine should be around 300hp with a better manifold and camshaft. I have run numerous engine simulations and they all look even worse than my numbers from the actual dyno test although the peak torque and peak hp rpm numbers are at the same rpm the dyno shows. This is why I asked for original numbers from a stock restoration build to see if the factory numbers were realistic. Although the engine sounds great the numbers are disappointing. A bit confused. Thank you for all of your recent responses.

That is a tiny cam. The headers are very mismatched IMO for the rest of the combo (dyno headers?). Based on a ton of info I have gathered over the years, your results seem like they are in the ballpark of where they should be. Stock, those heads just don’t move much air...peak airflow is around .400” lift, flowing around 183/112@28”. The exhaust side really responds to some simple quick and easy porting. The intake takes more work and are thin in all the wrong places.

You have the compression and supporting parts. Unless you’re going to put this in something really heavy or with tall gearing, I would add another at least 10 degrees duration on both sides. BTDT many times and have always been happy with the results for a mild driver. JMO of course

[My427stang]

You probably have 49 degrees or less overlap, which means the headers are likely not hurting as much, but you aren't getting much cylinder fill during overlap combined with the low lift either

That being said, the stock cam for the 4 barrels, I think was the same as the J-code Mustang, 115 LSA, and indexed on 114.5 if I remember correctly, might have been 115.5 , been a while. Likely had a smidge more advertised than the Comp you have now and similar .050, and the advertised could be much less with the Comp especially if it's an XE series, but the key is that the original cam likely hung in a lot longer than you'd expect because of advertised duration and indexing (along with partially being BS numbers back then LOL)

I think your RPM intake should help, and assuming the use of the engine, if you have the compression and can live with a little less low end you could retard the cam a little, however 280 HP doesn't sound incredibly off. I would like to see your exact grind and know the use/compression, ettc

One last point, at your lift, a stock set of 351 heads likely flow 170-ish on a good day, I think that sounds like a good little engine for what you have in it.

In the end - in the 60s and 70s, HP ratings were likely higher than they really were, and you didn't make any drastic changes, maybe even throttled back a little, except for the intake.

[af2]

In the end - in the 60s and 70s, HP ratings were likely higher than they really were, and you didn't make any drastic changes, maybe even throttled back a little, except for the intake.

Except for the high performance engines that were shut off 3000 rpm less than when they started making steam..

[Galon]

I guess my expectations were a little high.I have recently dynoed a 351w with the GT40P heads and that made a respectable 380hp. Both builds were close to the same build except the 380hp had a better hyd. roller and or course the heads. The 281hp motor was also limited on the cam selection because of the positive stop rail rocker assembly. Getting the preload was tough and also maintaining geometry. Quite a difference in heads. I never realized the manufacturers number were off on the 290hp 351w. I also realize hp makes sales. The headers I am using are my shop dyno headers and aren't the optimum for this application. I'm hoping both of these engines mentioned are streetable pump gas motors. I dynoed both on Sunoco 98 octane unleaded fuel to intentionally stay away from detonation. Maybe a pull on pump gas would be smart. Thank you for your paying attention to my concerns. I plan to make a few additional changes, such as carb spacers and maybe an open header pull just to see if there is anything left. Any improvements I see I will report. Thanks again.

[n2omike]

The 1969 and 1970 heads were the best two years. They had the bigger valves, and also smaller chambers. After 1970, the chambers got huge. The C9OE and D0OE heads were the ones to have. Of course, everything aftermarket (including the GT40) totally eclipses them every way...

There is a grey area around ‘75-‘76 where some may have had 69cc chambers, but every ‘71-‘76 head I’ve seen had a 64-65cc chamber. 1977-ish they went to the smaller 1.78/1.46 valves and 69-70cc chambers, and pedestal rockers.

The 69 and 70 heads, with the part number C9OE and D0OE had 60.4 cc chambers. They were the smallest chambers on the 351W heads, and had the biggest ports/valves... although they were still asthmatic.

The heads were initially designed for a 221ci engine, and weren't really changed all that much as the engine grew to 260, 289, 302 and 351ci. The heads are too small to make much power unless a LOT of quality grinding is done... and that is only to make power on a 289/302. 351 is is in desperate need of better heads.

[PackardV8]

For true. As I've mentioned before, I wasted some of the best years of my young life trying to make horsepower with OEM iron SBF heads. There aren't any good ones; some are slightly less bad than others.