Engine swap for 85 Bronco
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From: Colorado
Engine swap for 85 Bronco
I have a 85 300c.i. 6, which I would like to swap out for a 85 302c.i. EFI. ( Got the 302 for free) First question deals with removing the EFI and using a Weiand aluminum intake w/ Holly 600 4bbl. I do not want to change out the wiring harness, thus the carb vs. EFI.
Next, does anyone know the difference in the cam specs for the 85 EFI 302 and an earlier factory carburated 289/302? I have heard the angle of the distributor gear is different on the roller cam as well. I can change cams if I need to, but would prefer not to if the spec difference is nominal. I am planning on using an electronic ignition distributor from an earlier year, thus no computer.
Any other advice/comments will be appreciated!
Next, does anyone know the difference in the cam specs for the 85 EFI 302 and an earlier factory carburated 289/302? I have heard the angle of the distributor gear is different on the roller cam as well. I can change cams if I need to, but would prefer not to if the spec difference is nominal. I am planning on using an electronic ignition distributor from an earlier year, thus no computer.
Any other advice/comments will be appreciated!
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From: Colorado
Engine swap for 85 Bronco
I failed to state I have the vehicle which the donor 302 came out of. The engine is pulled, and I am removing the motor mounts from the frame now. Someone forgot to tell me what fun it is to pull the left mount!
Senior User
Joined: Apr 2002
Posts: 406
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From: cedar rapids usa
Engine swap for 85 Bronco
There is something about the distributer gear, but it escapes me at the momment. If memory serves, the roller cam uses a harden gear that will eat away a normal distributer gear. I beleive that you have to change to a bronze gear to run the old style distributer. Check the one you pulled against the one you want to use. If they look like they are two different kinds of metal you need to change them around.
Laughing Gas
Joined: Jul 2001
Posts: 1,019
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From: Bismarck, ND
Engine swap for 85 Bronco
I'm assuming your 302EFI is an HO, like, say, from a Mustang? I'm just guessing this as you mentioned that it's a roller cam, although some T-Birds and '90's trucks used the roller 302, also. As for the cam specs, I really can't compare the stock HO specs to an earlier 289/302, as there's no telling what sort of year, model, or other criteria we're using to qualify the term "earlier". Lots of variances there. I can provide some specs I had on hand for production 5.0 cams, which are: 5.0 Mustang - lift: .278/.278, dur. @ 0.050" lift: 210/210, valve lift w/ 1.6 rockers: .444/.444, lobe separation: 115. 5.0 T-Bird - lift: .238/.247, dur. @ 0.050" lift: 183/191, valve lift w/ 1.6 rockers: .381/.395, lobe separation: 107.5. 5.0 Cobra - lift .282/.282, dur. @ 0.050" lift: 209/209, valve lift w/ 1.6 rockers: .451/.451, lobe separation 118. Hope this helps!
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From: Colorado
Engine swap for 85 Bronco
[updated:LAST EDITED ON 04-Jun-02 AT 07:55 PM (EST)]302 is out of another 85 donor Bronco. I was told the 85 Bronco 302 EFI had the roller cam. I haven't gone internal yet, just trying to get as much information as I can to help me decide if this is a good swap, or will be a pain for life....... I do like the 300 6, but I tow a small boat or a pop up camper on the highway and it just can't cut it in the hills here in Colorado.
Cam issue is whether or not the existing cam will work well with the 4bbl, or if I need to change it out and go with a something different. $$$ are an issue here.
DUH, I just found the supposed cam lobe lift in the Haynes manual for the 80 - 94 Broncos. No differentiation between carburated/EFI 302's.
intake - 0.2375 inch.....exhaust - 0.2474 inch
No other info published. Sounds similar to the 5.0 T-bird cam, liftwise.
I do appreciate all the info I have received!
Cam issue is whether or not the existing cam will work well with the 4bbl, or if I need to change it out and go with a something different. $$$ are an issue here.
DUH, I just found the supposed cam lobe lift in the Haynes manual for the 80 - 94 Broncos. No differentiation between carburated/EFI 302's.
intake - 0.2375 inch.....exhaust - 0.2474 inch
No other info published. Sounds similar to the 5.0 T-bird cam, liftwise.
I do appreciate all the info I have received!
Postmaster
Joined: Aug 2001
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From: Nevada
Engine swap for 85 Bronco
I hope you're not setting yourself up for a disappointment. The 300 is a far better engine for towing than the 5.0.
1985 4.9 (300 ci) 120 hp @ 3200 rpm 251 ft/lb @ 1600 rpm
1985 5.0 (302 ci) 139 hp @ 3400 rpm 250 ft/lb @ 2000 rpm
Look at the torque numbers - the 300 is equal to the 302 at 400 less rpm.
Gearing would be a better solution.
1985 4.9 (300 ci) 120 hp @ 3200 rpm 251 ft/lb @ 1600 rpm
1985 5.0 (302 ci) 139 hp @ 3400 rpm 250 ft/lb @ 2000 rpm
Look at the torque numbers - the 300 is equal to the 302 at 400 less rpm.
Gearing would be a better solution.
Laughing Gas
Joined: Jul 2001
Posts: 1,019
Likes: 3
From: Bismarck, ND
Engine swap for 85 Bronco
I believe the duration on that stock truck cam (@ .050" lift) is 180'ish. I know it's pretty sick. If the engine is the original in the '85 donor Bronco, than it doesn't have a roller cam. While the '85 and later 302 truck blocks could accept a roller cam and lifters (conversion kit is available from FRPP), Ford installed a hydraulic flat tappet cam in them (EFI and carbed) from the factory. This remained the case through somewhere around '93 or '94, I believe.
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From: Colorado
Engine swap for 85 Bronco
I appreciate all the info/advice so far. I have found another FTE'er that pulled the same 302 EFI to carb change I want to do. He has provided much information (thanks Rick!), and has been happy with the results.
As for the 300 vs. 302, I do like the 300 when offroad, but tsryong to tow even approximately 800 lb boat/motor/trailer, it really dogs the 300 out at this altitude. Great for flatlander towing.......<4000ft altitude.
As for the 300 vs. 302, I do like the 300 when offroad, but tsryong to tow even approximately 800 lb boat/motor/trailer, it really dogs the 300 out at this altitude. Great for flatlander towing.......<4000ft altitude.
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Joined: Sep 2000
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From: Bay area
Engine swap for 85 Bronco
>I hope you're not setting yourself up for a disappointment.
>The 300 is a far better engine for towing than the 5.0.
>
>1985 4.9 (300 ci) 120 hp @ 3200 rpm 251 ft/lb @ 1600 rpm
>1985 5.0 (302 ci) 139 hp @ 3400 rpm 250 ft/lb @ 2000 rpm
>
>Look at the torque numbers - the 300 is equal to the 302 at
>400 less rpm.
>
>Gearing would be a better solution.
>
>
I agree, I think your setting your self up for dissappointment. but it is your truck.
the 302 will rev higher than the 300, but the 300 in my mind is a better tower than the 302.
If I was going to do something like this again, I would drop in a built 351w for the higher power, or a built 300. Cam, headers, and a 4 barrel on the 300 will make it a bear!
>The 300 is a far better engine for towing than the 5.0.
>
>1985 4.9 (300 ci) 120 hp @ 3200 rpm 251 ft/lb @ 1600 rpm
>1985 5.0 (302 ci) 139 hp @ 3400 rpm 250 ft/lb @ 2000 rpm
>
>Look at the torque numbers - the 300 is equal to the 302 at
>400 less rpm.
>
>Gearing would be a better solution.
>
>
I agree, I think your setting your self up for dissappointment. but it is your truck.
the 302 will rev higher than the 300, but the 300 in my mind is a better tower than the 302.
If I was going to do something like this again, I would drop in a built 351w for the higher power, or a built 300. Cam, headers, and a 4 barrel on the 300 will make it a bear!
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From: Colorado
Engine swap for 85 Bronco
>If I was going to do something like this again, I would
>drop in a built 351w for the higher power, or a built 300.
>Cam, headers, and a 4 barrel on the 300 will make it a bear!
Since the 302 was a freebie, and $$$ are an issue, I can't do a 351.
As for the 300, it is a fresh engine, having only about 15000 miles on a rebuild. Rebuild included new factory cam, pistons, rings, etc. Intake and exhaust were also ported. Reason for rebuild: all 6 cylinders had broken rings....did not bore since they were all smooth, not a ridge in any.
I am totally dissatisfied with the 300 for towing. Hit a hill, and the joggers wave as they pass you.... It might be fine for flatland towing, at or near sea level, but for the mountains out west, it is terrible. Gearing would definitely help, as would going to a smaller tire. Currently I have 275-75-15's, much too tall.
I am going on with the 302 swap.
I will post how this goes, and whether or not I am satisfied. If nothing else, I need the experience!
>drop in a built 351w for the higher power, or a built 300.
>Cam, headers, and a 4 barrel on the 300 will make it a bear!
Since the 302 was a freebie, and $$$ are an issue, I can't do a 351.
As for the 300, it is a fresh engine, having only about 15000 miles on a rebuild. Rebuild included new factory cam, pistons, rings, etc. Intake and exhaust were also ported. Reason for rebuild: all 6 cylinders had broken rings....did not bore since they were all smooth, not a ridge in any.
I am totally dissatisfied with the 300 for towing. Hit a hill, and the joggers wave as they pass you.... It might be fine for flatland towing, at or near sea level, but for the mountains out west, it is terrible. Gearing would definitely help, as would going to a smaller tire. Currently I have 275-75-15's, much too tall.
I am going on with the 302 swap.
I will post how this goes, and whether or not I am satisfied. If nothing else, I need the experience!
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Joined: Jul 2001
Posts: 237
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From: Clearwater USA
Engine swap for 85 Bronco
I should have jumped into this earlier but, here I go. I have an 86 with a 302 EFI that I just rebuilt last year. I stuck with the EFI because of money (did not have the extra to do all the switching). If you go with the 302 make sure you get a good RV cam and a good intake manifold also get some decent headers. I live in west central Florida about as flat as you can get and I am not that happy with my 302. It just doesn't have any *****. It's okay around town and pulling my friends boat about a 22 footer. I have 32 tires and a 3.55 rear and it does okay. My motor is pretty much stock if you do some of these upgrades you might be happy with the 302. I understand a free motor is hard to turn down, I had no extra money for my rebuild thats why I stuck with the 302. If I get ahead of some of my bills I am going to drop a 460 or better yet a cummins diesel into my Bronco. Hope this gives you some ideas, Good Luck,
Rick
86 302 EFI, bored 60 over, AOD,
Headman Headers, Flowmaster 40 series,
2 inch dual exhaust, MSD ignition
Rick
86 302 EFI, bored 60 over, AOD,
Headman Headers, Flowmaster 40 series,
2 inch dual exhaust, MSD ignition
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From: Colorado
Engine swap for 85 Bronco
Thanks Pilotrick!
I don't know if I'll be able to change the cam or not....I do agree it would be the wise thing to do. I think the Wieand split plane manifold and 4 bbl will be helpful, as well as a 1" spacer. Need the spacer for the EGR connection. Should help with vacuum too.
As for towing, I tow a 14 ft. deep-V fishing boat, maybe 800 lbs total. Once a year I tow a small pop-up camper, loaded maybe 1500 lbs, but also have the Bronco loaded with gear and 2 other adults. I have towed the boat out on the plains east of here, and it is acceptable if you don't have to pass anyone. Try to get around a semi, have to get one heck of a run at it to break through the air off the cab.
I don't want to spend much at all, as this is a 'beater' Bronco. If it rusts much more, it will be more of a swamp buggy than anything else! A frame w/5 gallon paint bucket seat.
I don't know if I'll be able to change the cam or not....I do agree it would be the wise thing to do. I think the Wieand split plane manifold and 4 bbl will be helpful, as well as a 1" spacer. Need the spacer for the EGR connection. Should help with vacuum too.
As for towing, I tow a 14 ft. deep-V fishing boat, maybe 800 lbs total. Once a year I tow a small pop-up camper, loaded maybe 1500 lbs, but also have the Bronco loaded with gear and 2 other adults. I have towed the boat out on the plains east of here, and it is acceptable if you don't have to pass anyone. Try to get around a semi, have to get one heck of a run at it to break through the air off the cab.
I don't want to spend much at all, as this is a 'beater' Bronco. If it rusts much more, it will be more of a swamp buggy than anything else! A frame w/5 gallon paint bucket seat.
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