95 Berlinetta weight reduction and modifications.

Here is the other head.

Exhaust porting stops abruptly well before the flange (can see this amplified by carbon build up in some ports). Bowl work is hard to see but rather lumpy compared to the other head.

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I then took that cylinder head and modified the exhaust ports to match the other head.


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Thanks and agreed.

Just used normal porting stuff, air die grinder, carbide burrs, sanding rolls.

 

Of any interest? I don't know. Here is progress anyway. As pictured in the last post, bowls are abrupt/lumpy to start. Maybe hard to see, shiny spot is high spot...

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All the time I have spent is blending the ports to remove sharp changes in angle/area but at the same time, making an effort to not enlarge the port while doing so. The mcsa (minimum cross sectional area) is already sufficient if not oversized for the displacement/rpm. Also the mcsa is near the valve guide like other multi valve heads.

Throat (lower edge of valve seat insert) was ported/blended to 23.3mm or 88% of intake valve.... and was wildly inconsistent to start.

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I didn't flow them and have no plans to. Doing what I described was the goal and as mentioned, mcsa is already on the large side for displacement/rpm.

Increasing the mcsa would have increased flow if I was chasing flow numbers but don't think that would result in better performance unless re-cammed for much higher rpm.

 

Sent the heads off to Lesco. In the meantime collecting parts.

For head gaskets, I've read of some difficulties with Elring/production changes.

Thought I might go with Toda but decided against MLS as not sure if it would play out well with liner protrusion.

After further research I decided to go with Murray Glegg (in Australia).

A pleasure to work with and seems to be a very high quality part.

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Yes of course.

Everything I do with the car will be checked on the dyno and backed up at the drag strip. Not that it's a drag car, but I think it's worthwhile to see improvements in at least trap speed to back up any power gains or weight loss.

 

Thanks guys. As for what it dyno's I'll be happy to make any gains at all.

These are highly optimized compared to other engines from the same era so it's just as easy to go backwards as forwards. I am treading carefully.

The gasket cost is inline with anything else out there as far as I know. 440 for the pair and 80 to ship to the states.

 

As for the throttle bodies. Overall super nice (in my opinion). I measured the mcsa (minimum cross sectional area) to be at the throttle shaft.

Also, a bit of a ridge/step below the throttle blade.

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I measured the entry angles at the cylinder head intake port. Center valve, outside valves, different sides, all different. Each one transferred and matched to the exit of the throttle bodies and blended.

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Back to the shafts. Masked off the bearing points and aero profiled the shafts with a die grinder and carbide burr. Countersunk fastener holes. Re-assembled with new lubricant and loctite.

And, original pic for comparison.

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Thanks. I'm using red loctite and did a trial run. (tightened screws with blades in place and let set up overnight). Was very difficult to remove the fasteners. Even after initial breakaway, lots of drag to remove.

I can stake them as well.

 

^ Thank you. It's going to be a while.

Last thing I feel is worth mentioning with the throttle bodies.

To balance them there are test ports, which is the extended fitting off the side of each TB and also balance screws that adjust how much air is getting around the throttle blade.

There are some recent threads discussing some of these fittings missing and some tightened down so far they are nearly impossible to remove.


Without getting too far into it I think the root problem is old o-rings on the test ports and adjusting screws that do not seal.

Unless replaced they have been there almost 30 years and are flattened out.

So, if you break free a tapered test port to balance the throttle bodies but the o-ring on that fitting is petrified/doesn't seal in the bore, anything you do from that point on, with the best intention, is a waste of time.

Maybe there are factory parts for this but I ended up using o-rings from McMaster Carr.

2857T112 and 2857T113 (2 packs of 5 for each part number)

(old left, new right)

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Heads are still out. (No matter) 40 custom Ferrea valves were ordered at +.5mm (slight oversize so there's room on the seat for a multi angle valve job)

Received some parts from Hill Engineering (thank you!). A bunch of stuff but mainly their tensioner pulleys, clutch release bearing with new springs and a lightweight flywheel.

They said they do not recommend the flywheel for street use. I thought I might get away with it with the continual weight loss program.

Thinking I should upgrade the propeller shaft now as well.

Being I have an early car the flange for the release bearing has a narrower centerline for the return springs. I just dropped a cutter with same spring ID/OD at the new 86mm centerline, just under 1mm deeper so the spring would locate. (new springs longer so no worries on that)

Also ordered fasteners for the flange with an integrated/large washer OD to help with any part flex.

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