Hi everyone, looking to a little upgrade my 1641cc engine. I’m considering putting a pair of performance heads.
C13-98-1381-B - EMPI - GTV-2 HP CYLINDER HEAD - 40X35.5MM W/SINGLE HI-REV SPRINGS (WITH COMPETITION VALVE JOB) - BORED FOR 85.5MM
Would this upgrade be worth it? Or should I keep it stock?
I am running dual Solex carbs with a Engle 100 cam and a Pertronix ignition system.
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figure how much HP U want and go for it,,HP=$$ dont get enough and it haunts U at night wondering IF i had 40 more HP...
I'd add 1.24:1 solid rocker assembly and a decent exhaust - might get close to 20 more hp.
I have used 1641cc builds in a number of speedsters and buggy's coupled to a 3:88 R & P transmission. John Brown in Dunbar WV does a great job building long blocks for me. No external oil cooler - fan is necessary. Counterweight crank, weighed rods then balance it as a rotational unit w/ flywheel. ( lightened flywheel on a smaller cc engine isn't noticeable and not worth the expense) w/ a 1641 stock heads are fine and per Wolfgang 1:25 - 1 with good springs will help a bit too. 100 cam is fine for the 1641. The stock clutch will suffice but use a name brand. I run dual Solex carbs on the 1641's adding a intake manifold cross over balance tube. (Your upgraded heads are a plus too.) A good distributor with electronic ignition and a quality wire set. I also add on a spin on oil filter - pump. Go for a decent flowing exhaust ( Tri - Mill etc.) On a side note, add all of this up and also estimate a1915cc upgrade and decide what the budget will be.
Your 1641 cc engine's powerband (with the Engle W100 cam) is all over by 5,000 rpm (or so) while the bigger valved heads will only really start to come into their own above 6,000 rpm. The bottom end/lower midrange won't be as 'crisp' as it could be, this will show itself as slightly poorer mileage, and valve springs won't last as long with the bigger (and heavier) valves either. I know the mileage probably doesn't matter, but it's a sign that the combo isn't optimal, and the engine won't be making the power it could be where you spend most of your time driving. Properly ported 35x32 mm heads with the 1.25 rockers (as Wolfgang suggested, make sure the compression is around 8.25:1, minimal (.040-.050") deck with no sharp edges in the combustion chambers and the engine will be way more fun than it would be with 40x35 heads on it. Al
@ALB posted:Your 1641 cc engine's powerband (with the Engle W100 cam) is all over by 5,000 rpm (or so) while the bigger valved heads will only really start to come into their own above 6,000 rpm. The bottom end/lower midrange won't be as 'crisp' as it could be, this will show itself as slightly poorer mileage, and valve springs won't last as long with the bigger (and heavier) valves either. I know the mileage probably doesn't matter, but it's a sign that the combo isn't optimal, and the engine won't be making the power it could be where you spend most of your time driving. Properly ported 35x32 mm heads with the 1.25 rockers (as Wolfgang suggested, make sure the compression is around 8.25:1, minimal (.040-.050") deck with no sharp edges in the combustion chambers and the engine will be way more fun than it would be with 40x35 heads on it. Al
I appreciate all the input. Thanks
