[Capndirk]

Did you get the E-head figured out? For what it's worth, I was a dealer line mechanic when the '71 142-E came out. It was a half-year car IIRC, and had high performance creds at the time. Seems like compression was something like 11.5:1, but don't take that to the bank. The cars only came in gold with black leather, and I ended up buying one later on. The things were a treat to "road-test" because they really moved out and handled stiffer. Wider tires and wheels, heavier sway bar, maybe?
Anyway, if the head is a '71 "E" there could be a lot of pre-detonation issues with the high compression ratio. I think they were specced for 100+ octane. The 1972 models were de-tuned, but ran strong. That's what I remember about that period, except for what an ordeal it was to finally identify the dying while driving issue, that turned out to be the E-system temp sensor.

 

[4runner]

You had a tt4 but sold the engine. Did you run it before you sold it? How did it idle? I’m thinking 9.5 as well. Did tinus do the head as well?

 

[blazink]

The combustion chambers on my E head are 45cc, so the static compression ratio will be about 10.8:1. Maybe a little high, but my research says it will probably be OK. The truth will come when I get this put together and on the road.
I live at 7000 ft elevation, so the extra compression will help regain some power. My cam has some overlap too, so dynamic compression will be a little lower.
In the end, I won't mind if I have to run some octane booster. This isn't a daily driver and it would be more likely at lower elevations.

 

[142 Guy]

The combustion chambers on my E head are 45cc, so the static compression ratio will be about 10.8:1. Maybe a little high, but my research says it will probably be OK. The truth will come when I get this put together and on the road.
I live at 7000 ft elevation, so the extra compression will help regain some power. My cam has some overlap too, so dynamic compression will be a little lower.
In the end, I won't mind if I have to run some octane booster. This isn't a daily driver and it would be more likely at lower elevations.

45 cc is on the money. That is the same chamber volume as I measured for my 1971 B20E. My pistons sit 0.020" below the deck and allowing for a 0.047 " gasket height (al fuel injection gasket kits now come with F gaskets) and the fact that my engine is bored 0.030" over, my static compression ratio comes out at 10.0:1. If I yank the head and retrofit a B20B head gasket my CR will end up at around 10.5 which is what stock would be.

With the 10:1 CR and running 92 octane with the D cam grind, I get a slight amount of detonation right around 3200 RPM at high MAP values. I am running MSExtra with spark control, so its very easy for me to flatten the advance curve a tad while allowing full load advance to return to 32-33 deg above 3500 RPM. The fact that my pistons are 0.020" below the deck and I have the 0.047" F head gasket means that my quench clearance is probably ineffective. If I decked the block to have the pistons flush with the deck and installed a 0.027" Cometic gasket, I could probably run the 10.5:1 CR with more aggressive advance at 3000 RPM with no detonation. Based upon the experience of others with the B20 running tight quench clearances I might be able to run 89 octane with no detonation.

The exhaust port is the primary restriction on the B20 engine. It would also help Ve if the intake was on the other side of the head so it does not get preheating from the exhaust manifold; but, that is a little beyond the scope of the average engine builder. The photo below is a cross section of the exhaust port.



The top of the port around the valve stem presents a significant restriction. You will also note that the port necks down just above the valve seat. Received wisdom is that the safe thing to do is to open up the area above the valve seat to the same diameter as the valve seat - removing some of the material on the right edge of the port in the photo. More aggressive porting involves smoothing the boss around the valve guide (in effect shortening the guide) to create a more uniform port along the top. In addition to having the boss smoothed out this port has been opened up above the seat to match the ID of the seat.



Whatever you do, do not open up the port near the exhaust flange opening. In the cross section of the port you will note that on the right side of the port above the exhaust valve seat the path takes a sharp 90 deg bend. Not good for flow. Opening up the port by grinding out the lower portion of the port floor makes bend this worse. Very aggressive porting involves filling in the bottom of the exhaust port with welding rod or brazing, in effect making the exhaust port smaller at the exhaust flange; but, resulting in less disturbed flow. I have some pictures of B20 exhaust ports that have been raised in this manner and will post them if I can find them. I have also heard of a non welding / brazing approach that involves welding a tongue on to the exhaust flange and this tongue fits into the exhaust port filling in the floor area. I have not seen one of these tongue arrangements. Doesn't bear thinking about what would happen if the tongue came loose!

Received wisdom is that improvements on the exhaust port get you a high initial return. Even with no cam change the improvement in Ve increases power and better flow helps with heat build up in the port area - presumably with reduced tendency to detonate when using higher CRs.

As an aside, if you also have an F head you might want to have a look at the exhaust ports. I have read internet chatter that the F head ports have more material on the floor of exhaust port so may have a better shape. I have never seen an F head and I haven't seen any photographic proof of this so it may just be chatter. If the exhaust ports were a better shape it might be better to machine the F head to increase its CR to the same as a E head although, unless someone can tell you exactly how much to take off to yield a 45 cc chamber volume having to do multiple passes with measurements between each pass could be a rather expensive venture.

 

[blazink]

Thanks for the very informative post 142 Guy. It sounds like I am on the right track with my slightly hotter cam, tighter quench, and high elevation.

My block is decked for zero piston clearance, with a 0.036" head gasket to help with quench.
I may open the combustion chamber a little to get my compression ratio below 10.5:1 (needs about 2CC more volume). I will also do some mild porting in the exhaust. Any photos of B20 port work would be appreciated.

I can confirm that the F head has significantly more material in the floor of the exhaust port. I haven't measured, but it looks almost twice as thick.
For now, the F head will be stored with hopes of someday building a forced induction engine with lower compression ratio.

 

[dcthompson]

So having said that, I asked around a few years ago and it seems that all the good Volvo B20 Head guys have sailed into the sunset.

"You could contact Eric at HiPerformance in Torrance California and see if he knows anybody,

http://hiperformanceautoservice.com/

or perhaps Cameron or Phil know someone that they can recommend."

Phil S. is back to rebuilding heads using his own "secret sauce." PM me if you want his contact information.

 

[volvorelix]

Not to take this too far on a new tangent, but just for everyone's info: Phil has retired from engine building. Swedish Relics has acquired Phil's design specifications and full rights and access to all proprietary custom components. Through this collaboration, all future Singher spec engines will be the result of consultation with Phil directly while the engines themselves will be assembled by Swedish Relics.

Aside from that: I've done business with Eric and Ian at Hi Performance, with KG Trimning, and with Tinus Tuning. I highly recommend each of these companies.

Thanks,

Cameron
swedishrelics.com

 

[dcthompson]

FWIW, Cameron is building a B20 (yes, I'm keeping the original B18) for my 123GT. It's going to incorporate the usual go-fast goodies, including 45DCOE Webers, forged pistons, 123 distributor, lightened flywheel, and more, plus a head modified to Phil's specification. I am told that I should expect to be impressed.

 

[R32rennsport]

FWIW, Cameron is building a B20 (yes, I'm keeping the original B18) for my 123GT. It's going to incorporate the usual go-fast goodies, including 45DCOE Webers, forged pistons, 123 distributor, lightened flywheel, and more, plus a head modified to Phil's specification. I am told that I should expect to be impressed.

Looking forward to comparing notes, my build is nearly identical specifications.

Cameron, good to know that Phil has entrusted you and that you stand by those in the industry that I've come to trust myself.

 

[BF Flyers]

- I know this post is several months old, but I was wondering how this build panned out? I have spoken with Cameron before, but he is on the other side of the continent (I may call him again anyway).

I assume this thread is pretty well concluded (?). But I came here initially to see if there is someone on the east coast who KNOWS orange block Volvo engines, and can port heads (exhaust porting) to their best modern spec. As noted above, and other places before, the big restriction in the B18 and B20 is the exhaust port. I also know the process for porting such beasts has eveloved over time. It seems that you really need to know what you are doing to get it right on this machine. I was going to ask the forum if there is a machine shop on the east coast, one that knows these heads and how to port them well. As noted (indirectly), it's not just any head to port.