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| REPLY TO THIS MESSAGE |  | PRINT | | SAVE | | B20 block and head choice for performance build 120-130 | | posted by someone claiming to be amazonphil on Tue Nov 15 01:19 CST 2022 [RELATED] | | I did mine years back but it was about a 75 I got the head from. I seem to remember something about using the lighter rods and heavier crank, used the D cam, polished the ports and had an engine shop do stainless steel seats. I did not try to plane the head or lighten the flywheel. I did have some valve float issues and ate a cam. I had changed the valve springs for original new ones but I think they were a bit loose. the valve stem length changed a little from reworking the head I think.. I added some shims under the springs and that helped valve float.. the balancing really made the engine I would definitely do that. I used an original style b18 but bored it to 2 litres.. I ground the rocker shaft down .020 and fitted all new bushings but reused the rockers which are bit hollowed out.. I made thrust washers for the edges of the pillow blocks. I used the 2 liter jets. HS 6 carbs the 67 exhaust manifold with 2 into 1.. I think it didn't have enough advance so i used a vacuum thing meant for a retarrd... somehow flipped the servo thig over to get more advance,, I somehow got it to work like that.. the distributor is from about a 74 and I took the electronic ignition module with it. it could probably be recurved more scientifically but it runs fine,, really lugs and it revs fine to about 6000 and sounds nice.. I kept the OEM peashooter exhaust. I had a cutout thing on it wiht a ball that opened up under high backpressure but it rattled,, I ditched that idea and plugged that off. it looks pretty stock if you don't notice the big valve head.. It really flies, I put in OD and lower gears,, I like the heavy flywheel its like driving a car with a gyro feature.. sure I have to pause when i shift but it's fun like that I can wind it up like a top. ;-) If you do too much you will just want to drive it like you hate it because you can and it's fun and you can race old ladys in their new hondas without them even noticing. ! | |
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| REPLY TO THIS MESSAGE | | PRINT | | SAVE | | B20 block and head choice for performance build 120-130 | posted by vvpete on Fri Feb 29 04:40 CST 2008 Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS]  [IGNORE ALL POSTS] last visit: Thu Jul 10 14:10 CST 2014 [RELATED] | | Use a '75 B20F FI block and a '72 carb head and intake which has the bigger valves and doesn't have the secondary throttle valves in the intake, optimally the best choice, if you can find these. A '71 B20E block is also a good choice, but good luck finding one. Things to note, the '72-74 B20F has the same bottom end as the 75, but the 75 has an improved forged crank and cam. The early B20F has cam problems as well as connecting rod/wrist pin is weak. I think the '74 B20F has the improved D cam and better bottom end, but has the 6-bolt crank. Note that all B20E/F blocks have a slightly different bore/stroke geometry (more square, shorter stroke) than the B20B and will be a better hi rev motor with a B20B head and high compression. -- '89 245 sportwagon, destroyed by hit & run driver, RIP. '04 V70 2.5 T Sportwagon, 12k mi and '91 245 5-speed, 209k mi, replaced the '89 | | -
| REPLY TO THIS MESSAGE | | PRINT | | SAVE | | B20 block and head choice for performance build 120-130 | | posted by Blue Horse on Fri Feb 29 06:51 CST 2008 Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] [IGNORE ALL POSTS] last visit: Mon Apr 8 17:57 CST 2013 [RELATED] | | First off, let's assume we're talking about US market cars, in which case the chronology is quite a bit different from what you describe: The B20B came out in 1969. It had twin carbs and 10.5 compression, and was rated at 125HP SAE gross. It was used until the end of the 1972 model year. The B20E came out in 1970 (in the 1800E) and was also used in 1971. It had, compared to the B, larger valves and improved porting, as well as the D Jetronic injection. These engines used a D cam. They were rated at 130HP SAE gross. As far as stock engines are concerned, this is the one to have. In 1972, the E was superseded by the F. The B20F (72-73) had slightly lower compression, a different head with more restrictive porting, and minor modifications to the D Jet system. These engines still had the D cam and 6 bolt crank. They were rated 125 HP, and are also good ones to work with. The 1974 model year is when the major changes took place. The engine was still designated B20F, but very little remained the same about it. This is where the 8 bolt crank came in, as well as hardened valve seats. Also, all the threads in the block were changed to metric. Previous versions had been SAE. The 74s had K Jetronic (CIS) fuel injection, and to go with it, a K cam. Compression was reduced still further. 74 was not a good year. These were the engines with the porous blocks and wear-prone camshafts. I refer to 74 as "the year of round cams and oval cylinders" In my opinion, they are best avoided, except that the head is a quick, easy way to get hardened seats, if you can find one. The 75 is pretty much identical to the 74, but with most of the quality control issues resolved. To answer the original question, if I were looking to build a carbureted performance street engine, I would look for any 6 bolt bottom end in good condition, and top it with, ideally, a 71 E head (with the injector ports plugged) or, as those are very difficult to find, a 72 or later F head, perhaps with a bit of port work to bring it up (more or less) to E spec. Don't go too high with your compression--10.5:1 is a reasonable upper limit. As for the camshaft, I have often heard that not all D cams were created equal, and that those in the 70-71 Es were more equal than the others, but have never seen any kind of official confirmation of this. | | -
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| REPLY TO THIS MESSAGE | | PRINT | | SAVE | | B20 block and head choice for performance build 120-130 | | posted by vvpete on Fri Feb 29 07:49 CST 2008 Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] [IGNORE ALL POSTS] last visit: Thu Jul 10 14:10 CST 2014 [RELATED] | | No. Not all B20 heads are the same, and if performance and high compression along with the larger valves are important to you, the only one's to work with are the early B20E heads and the one and ONLY US carb head that had the bigger, same size valves used on all the E/F heads as well as 10:1 compression is the '72 (up to '75 in Canada and Europe) B20B head. This head was only used on US wagon models and came with the HIF6 carbs, as all other models came with FI as standard, and the wagon was opt FI. If you take any of the later B20F heads w/larger valves, you would need to block off the injector ports and shave the head to up the compression, and do some porting to open up the flow. Just using a thinner head gasket is not enough to get it to 10:1 or greater. -- '89 245 sportwagon, destroyed by hit & run driver, RIP. '04 V70 2.5 T Sportwagon, 12k mi and '91 245 5-speed, 209k mi, replaced the '89 | | -
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REPLY TO THIS MESSAGE  | | PRINT | | SAVE | | B20 block and head choice for performance build 120-130 |  posted by B20Paul. on Thu Jan 27 21:40 CST 2022 Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] [IGNORE ALL POSTS] last visit: Mon Oct 20 10:54 CST 2014 [RELATED] | | "Why would the '73 B20E heads not be as good as the '70-72 heads?" The actual BEST choice is 1973+ B20A From around 1973, or whenever the previous batch of heads run out, the exhaust port changed & I think there is a tiny bit more meat in the inlet port in the right place for porting. EXHAUST PORT: This is the biggest choke point in B18 & B20 If you sit the head flat on a bench, then sit down and look in the exhaust port at the FLOOR from the manifold face to where it turns down to the valve, the early heads rise up about .125"/3mm. In the 73+ heads the floor raises up about.25"/6mm. This lets you make a much better Short Side Radius(SSR). If you can't weld, then this is a big advantage. Most people hack away at the LSR which actually needs metal added for most purposes. In the beginning, I only had one choice, I welded up the floor to make it about 10mm higher inside, gives a great SSR. Using a near stock B20E valve I got the flow up to 80cfm@10"H2O which is roughly 133cfm@28". Both early & late heads are so hit & miss that the flow is around 60cfm max. (6 banger B30A/E exhausts, which are round, max out at 55cfm.) INLET PORT: The E head needs nothing done to it if you are only lifting the valve to .25D, just careful seat, bowl & chamber work. This is a quick & easy IF YOU HAVE all the tools. Works fine with Twin 45DCOE & the stock injection manifold. BEST INLET PORT: Starts with an A/B head because the port is smaller & you can leave metal in places where it is already gone from & squeaks up the mid-lift flow a little & the velocity too. The A head is thickest, so you keep those for Stroker usage. "Volvo Owners Club engine chart shows the same specs for all 3 years." That's because they read it from a book. In 1974 the B20E cam changes from D to K, which looses approx 5 BHP peak, but, the K cam with a stock or mild head is equal to or better up to 5500rpm & much kinder on the valvetrain. The graphs shown by Volvo are 'artist interpretations'. Although it's a very average intake, a B20E/F should still show some kind of double hump in the power/torque curves. In one 'good' source, there is an B20E that makes 135BHP, it's a misprint, but it drives some people nuts looking for the specs of this unicorn. ENGINE BUILDING: Do you have a spare engine? Bolt it up to engine stand & get the stuff you need to degree in a cam & play with that. If you can't master that skill then you can't built even a stock engine properly. | |
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| REPLY TO THIS MESSAGE | | PRINT | | SAVE | | B20 block and head choice for performance build 120-130 | | posted by Deluxe on Fri Feb 29 08:07 CST 2008 Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] [IGNORE ALL POSTS] last visit: Fri Sep 25 07:10 CST 2009 [RELATED] | | Well, I'm thinking that a block won't be too difficult to find, but a specific head will be. I think a lot of people will know that their head is a B20 head, but they may not know the exact year, specs, etc. I've been cruisin' eBay for 122 stuff for at least a few months now and haven't seen a head or engine on there. There's a B20 on eBay right now in Tenessee, a little far away for a block that I can probably find locally, and I think it is a '75 or later. Where do I go to get a desirable head? I can probably get a block here in my state. I have a 95% complete running and driving '65 wagon that I'll trade for a good B20 engine. The car is about what you'd expect from a person who is willing to trade it for an engine, but it is a cool, nearly complete, '65 with a B18. Deluxe | | -
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| REPLY TO THIS MESSAGE | | PRINT | | SAVE | | B20E head on eBay - $15 120-130 | | posted by someone claiming to be paul on Fri Feb 29 13:18 CST 2008 [RELATED] | | Looks rough, but if you're planning on a rebuild: http://cgi.ebay.com/ebaymotors/Volvo-144-145-1800-P1800-ES-E-S-B20E-Cylinder-Head_W0QQcmdZViewItemQQcategoryZ6755QQihZ004QQitemZ140210498718QQrdZ1QQsspagenameZWDVW Paul | | -
| REPLY TO THIS MESSAGE | | PRINT | | SAVE | | B20E head on eBay - another one 120-130 | | posted by someone claiming to be paul on Sat Mar 1 03:46 CST 2008 [RELATED] | | This going off today->$90 http://cgi.ebay.com/ebaymotors/B-20-LARGE-PORT-INJECTED-HEAD-VOLVO-1800-E-S-ES-122_W0QQcmdZViewItemQQcategoryZ33617QQihZ018QQitemZ280203507062QQrdZ1QQsspagenameZWDVW | |
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| REPLY TO THIS MESSAGE | | PRINT | | SAVE | | B20E head on eBay - $15 120-130 |  posted by JohnMc on Sat Mar 1 01:37 CST 2008 Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] [IGNORE ALL POSTS] last visit: Thu Oct 23 07:42 CST 2014 [RELATED] | | Here's a general guide to what sort of head it is (I wouldn't trust the eBay descriptions on most parts, even if it cam off a '71 1800E there's no guarantee it started off on one). First look for injector pads - the raised, machined areas over the intake ports. If it doesn't have those, it's either a B18 or carb B20 head, and you can discriminate between those by weird 'umbrella' valve seals at the top of the stem (B18) (I'm not sure how those work, even in general theory) vs. the 'real' seals, inside the springs on the valve guide (B20). If it has injector pads (even if not drilled out) then it's a later head, and should have the bigger valves of an injected head. Next, look at the center head bolt on the manifold side. There is a little raised, machined surface for the bolt to torque onto. If this is completely surrounded bu lower, rough cast metal, it is a B20E head. If it is connected to one and only one of the nearby raised machined injector pads with a little strip of raised machined metal, then it is an early B20F head. If it is connected on both sides to both nearby injector pads with raised machined metal, then it is a late B20F head. If you get an injector head with undrilled injectors, it might be something interesting (like an R-sport head) or it may have just been a late production carb head replacement from the parts department. R-sport heads will generally have a stamped part number on the upper surface, in the same general area as the center head bolt, on the manifold side. They sold different flavors of the heads too, so I'm not sure what differences there would be on all of them. From what I understand the late B20F heads are the ones with the most potential for improvement, because they used different internal casting cores, and there is more metal in the places it needs to be ported more for better flow. Try to port an earlier head as much and you'll hit air in the ports. -- '63 PV544 rat rod, '93 Classic #1141 245 +t | |
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