Got to thinking about the thread "Big Bore, Ported Heads or ......." and some of the posts.

I started looking at my "Screamin Eagle Pro Racing Parts: 2008 Competition and Performance Parts for the Experienced Rider" catalog.

It's got a wealth of Dyno charts that compare almost any combination of "street legal" with "race applications only" parts in the catalog. [Some great info and where I usually go for a quick reference when someone asks: "what kind of results can I expect from ... ?"]

After mulling over a post (#27) by forum member Grind: "if you can't swing [Big Bore] and heads at the same time, heads would be my first choice after cams. Hell, I've even done heads before cams. ... My opinion comes from building hot street/autocross motors ...."

I thought for a relatively economical build (about a third of the G-Squared quote received by 2QuietBob in post #34) that should produce upwards of 85hp and 90 ft-lb torque on a 88A.

Part No Nomenclature Qty Price Ext Pr
16953-08 KIT CYLINDER HEADS SILV 1 660.00 $660.00
32076-04 KIT COMPRESSION RELEASE 1 60.40 60.40
27623-05 SE 50MM THROTTLE BODY 1 311.94 311.94
17997-99A QUICK INSTALL PUSHROD KIT 1 114.60 114.60
DS-199180 TW37B CAMS 99-06 TWIN CAM 1 234.36 234.36
Shipping is 51.38
Total $1,432.68

The assumption is the build already starts with free flowing intake/exhaust and a fuel management module to be able to adjust to the increased air flow volume.

The heads are described as follows: "We've combined the proven Screamin' Eagle valve train components and innovative port shapes from our Evolution 1340 cylinder heads with the Twin Cam engine "bathtub" combustion chamber with a volume of 76cc to create a cylinder head that really performs. Valve spring can accommodate up to .575" valve lift camshaft kits and up to 6500 RPM. Heads are machined to accept Mechanical Compression Release P/N 32076-04. ... Fits '99-later Twin Cam ....'99-05 models require separate puchase of (2) Intake Seal Flanges P/N 26993-06 ..."

The Cams are Andrews grind. I think the 50mm throttle body uses the specified flanges ....

Prices quoted are Zanotti ... Chicago and Surdyke were about $120+ higher ... black was also a little higher by about $60.

Probably have some additional incidental costs, but if you did the work yourself, you could probably have a pretty hot set-up for around $1,500.

Any thoughts? (Well ... duh ... I'm sure y'all will have plenty to say ....)

R/
Priest

 

Wow ... guess not. I'd have thought at least Grind or 2QuietBob would have said "yes" or "no" ... ?

R/
Priest

 

Sorry, Priest. I missed this. Dunno how, I pretty much keep this forum open all day at work and most evenings (much to the chagrin of my wife ).

Doing heads with intake improvements sounds like an interesting build before going big bore. But, I've barely scratched the surface of HD hotrodding, so my knowledge is limited.

Like I said before, my experience is with small, old British cars. Funds weren't available for me to do my dream build until a few years ago. I had a lot of fun with an 850cc in a 1200lb car 20 years ago, though. I did a hot ported head with oversize valves, gnarly cam and a bigass carb. Friends with 998cc twin-carbed cars couldn't believe that my motor was only an 850.

 

Not a bad deal except that Screaming Eagle heads aren't known for their excellent flow characteristics outta the box. Better off having your old heads ported to match the profile of cam that you're planning to install.

With the 37 cams you'll lose low end unless you install a set of 9.5:1 pistons. Been down that road.

 

My first engine mods were to add 95" jugs, hc pistons, 211 S.E. cams, and a sert. It made 85hp and 93tq. It was a lot of fun and torque was across the entire rpm range to 6000. NO head work involved.

 

I wouldn't buy the heads but put that amount of money in having the stock heads done.

 

Priest,

I'd have to say that it all depends on how much you want. Remember, there is no replacement for displacement!

Here's a little something Bwickles put together for me last month when I asked a similar question.

-------HP----TQ-----HP imp-----TQ imp-----inc cost
Stock 67 82
Stage1 75 90 12% 10% $1,120 SE A/C, D&D and PCIII
Stage2 98 101 31% 12% $630 Pistons, cam, bore, gaskets
Stage3 110 110 12% 9% $1,220 Heads and TB

Even HD would agree with the stages. These are the basic parts they include in their stage kits. So to jump over one stage is not getting the most bang for your buck.

I think his BB price is a little low, but that's figuring have your cylinders bored for 103" and using HD cast pistons. Zanotti's would be good to check with here for sure.

Also, I more than agree with the others here. Have your own heads ported. You will be much further ahead for the money! Besides, a good port job is done for YOUR build, not a generic off the shelf build. Too many variables with each build for that to work well.

Good luck!




Mike

 

I am considering doing something similiar, but will probably go w/ an HQ 103" build, they will give you a package of pistons,heads,cylinders,cam, ez adjust push rods,etc. for a little over 2K. Their conservative estimate for this build is 105HP and 115-125TQ. I will keep the TB stock. But I will also replace the wimpy stock compensator and crankshaft bearing for SE units, and SE clutch spring. Now I just have to justify the 3K. I already have done stage I, AC, Rineharts, and T-max.The sputhe positrac, and a brake upgrade, then I'll be done for a while. lol.