Looking to port my heads and change to R3 valves for better performance and HP. Maybe will add a Paxton someday but don't want to financially do all at once. Would appreciate response from anyone who has done engine upgrades like this on their Avanti. My engine is a healthy R1 with low mileage. Feel free to send PM. Thank you.
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Been gone over many times. I'd bet a "search" of the word porting...will bring up some good stuff.
To do it quick and cheap...the right way, isn't possible..!
If you are good with a high speed grinder, you may be able to do some good work. There are many locations in the Stude intake port for much improved flow.
One thing, do "not" bother going thru the expense and time of installing R3 exhaust valves. The stock ports and valves are already large enough for all but the biggest cu. in oversized engines (well over 300 inches).
Here is some of the work I've done.
With some VERY carefull work, the flow can be picked up past the flow of the "normal" Stude camshaft and intake manifold. But is not JUST about quantity...it's also about the "quality" of flow.
But the work shown is more about the quality of flow into the chambers.
And speaking of chambers...many don't realize that the combustion chambers are an extension of the ports and need to be simillarly modified. Smooth and remove all of the hard machned corners and sharp edges. Take a close look at the three folders on the Fotki site to see what I've done.
This work, if done right will also inhance the daily driveability
MikeLast edited by Mike Van Veghten; 06-11-2011, 08:23 AM. -
Who would you recommend to do this type of work reliably? I heard Solanki and Myers. My understanding is Solanki is an engineer so would think he would do more exacting work? Been in this hobby only 2 years and hardest part of anything I have upgraded is finding someone who does clean work without braking something else along the way.Comment
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I can clean and mill the heads, install new guides, positive seals, R3 intake valves, heavy duty stock exhaust valves, R2 springs, do pocket porting, for $995. The engine will be noticeably stronger in normal performance driving.
Getting someone to do the custom intake and exhaust port work to make your heads flow like R3 heads will cost about $2,000 in labor. You'll never notice the difference below 4,500 RPMs. How often do you plan to operate the engine above 4,500?
jack vinesPackardV8Comment
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Jack -
Mmmmm...I'd be willing to bet my $2500+ heads, you'll will notice a difference from the first tip-in of the throttle of a properly assembled engine...!
Jay -
There's only two people that really know how to make a stock head flow, both can be found on the Stude Racing site. And I dare say, Niemish (spell?) isn't one of them. And if it wasn't that obvious from the photos...I am one of them...! I've spent the last coupla years grinding and flow testing. While it's not the be all to end all, it's as close as we can come. Most of my work has been verified by the other guy doing his own work.
But as Jack notes...it's NOT cheap work.
Jacks work is worth that money.
Much more work...the cost jumps up very quickly.
And then there is another person or two that have made good headway but they aren't really streetable because of the extended use of epoxy.
MikeComment
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Mike, I'd take that bet, because nothing has been said to this point about an intake manifold. You know from Tom's flow bench work how a stock intake will choke down all your great head porting flow. There does not exist a commercially available intake manifold which will fit under the hood of a C/K/Avanti and equal the flow of your best ported heads. That's why I continually advise not to go to extremes on a street driven engine.Jack -
Mmmmm...I'd be willing to bet my $2500+ heads, you'll will notice a difference from the first tip-in of the throttle of a properly assembled engine...!
If one is willing to cut a hole in the hood of his Stude, spend the bucks on a custom intake manifold from Jeff Rice and take it to the strip regularly, then, yes, custom ported heads are the only way to go. If someone asked me to build such an engine, I'd start the quote at $3,000 for the heads and intake.
jack vinesPackardV8Comment
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Jack -
I learned a long time ago that there is two components to to good cylinder filling (unblown..!), one is "quantity" of air injested, the other is the "quality" of the properly mixed, air/fuel mixture. If you have a bunch of "stuff" in the way of "smooth" flow, yea, it MAY disturbe the flow enough to cut some of the quantity, but it can much easier disturbe the quality of the "mixture".
I learned this messing with motorcycle heads and carburetor designs (yea...the old days of carbs.). AND....some work to a Briggs & Stratten engines inlet and exhaust ports...!
When I started this trek into Stude head airflow, it wasn't so much to gain outright flow...but quality..that is "throttle sensitivty". The outright quantity just came as a result... I did overwelm the bowl/valve as shown during my last trip to the flow bench by making the begining of the port cleaner and just a tiny bit larger thAn the valve could pass cleanly.
So...my opinion, while you are correct as far as absolute flow, removing all the twists and turns as I have done, the air/fuel mixture has to circumnavigate to get into the cylinder are MUCH less thAn the original port design...which WILL aid in low throttle opening/low RPM power. And...all this goes a long way toward low and mid lift flow gains...which the flow bench has also been prooved. Tom has seen simillar results.
Low/mid lift flow gains shows upas low/mid rpm power gains.
I'd also bet that in using a "wet" flow bench, on a stock and modified head will also show a cleaner, smoother path....which WILL show up during low rpm throttle tip-in...leaving a stop signal..!
BUT...without a LOT of expensive testing, it's difficult to say exactly how much.
MikeLast edited by Mike Van Veghten; 06-12-2011, 10:26 AM.Comment
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