Latus Engine Upgrades

[jackio]

Saw on the Latus website a number of upgrades but all appear to be for at TC88 to take it up to a 95". Any of these work on a TC96 up to a 103"? Am I correct that none of these include the SE high output/high compression heads and pistons? If that's correct, why not? Lastly, thoughts on the 251 cams -- I'm looking for low-mid torque.

[Mike]

Essentially the same upgrades apply to the 96/103 upgrade. Main differences are cam and piston choices. We have nearly 100 new dyno charts to add to our library, and now that racing season is over I hope to get those updates in soon. There are some 95's listed with SE Performance, CNC and HTCC heads but due to the volume they can be hard to find. We offer heads ported by Baisley High Performance in "Superstock" at $750.00 or "Street-pro" for $1350.00 in addition to the SE line. They are VERY popular since we can attain similar hp/tq numbers to the SE heads at a reduced price and we offer them on an exchange basis. The SE products are going strong, has the advantage of being able to financed into a new bike sale, allows greater discount advantages during winter sales and can have warranty advantages when installed on newly purchased bikes.
The 251 cams are a very good choice so long as the heads and compression is enough to support them (minimum 10.0 to 1). We use them in our "Boss" kit (251 kits in our dyno library). They are similar to the 211's but the higher lift means they are not bolt-ins. We use the 211's with stock heads and the 10.25 pistons and the 251's with the Superstock heads. The 251's also look very good in the 103 with 10.0 compression and are "bolt-in" in '06 and later heads. This is the essence of our new 103 kit (yet to be added under engine packages on this site). Of course we also offer many cam, head and engine combo's that can be discussed individually.
Thank, Mike

[jackio]

You are the Man. A couple more questions:

Am I correct in my assumption then that the real difference between the SE heads and the Baisley is primarily cost -- if you are doing this to a bike already puchased (I bought the 07 in August)?

Is there any polishing necessary/useful with the SE heads?

Is there any reason to queston whether the high compression pistons and heads will get compression less than 10 to 1?

Assuming that compression with the SE high performance heads/pistons would be more than 10 to 1 with the 251 cams, what kind of hp/tq numbers would be expected?

When will your 103 kits be available? Thanks a bunch.

[Mike]

Our 103 kits are available now, we've just not posted them here. The SE Performance heads does respond to porting fairly well, but it requires a full port job which adds $1300.00 to the intitial cost of the heads. They do not respond well enough to the Superstock porting to be worth the added cost of $750.00. This is also true of the SE 103+ heads. The SE CNC head are already ported and require no additional work. These are actually a very good head and will flow slightly higer numbers than our StreetPro heads. It can be argued that the ports/valves in the CNC heads are a little too large and as a result low end torque does suffer.

For comparison, the SE Performance heads ($949.95), out of the box, flow similar numbers to our Superstock Heads ($750.00). The Superstock heads tend to be more consistant since the SEP heads are "as cast" and can vary. A fully ported SEP head ($949.95 + $1300.00=$2249.95) flows about the same as our BaisleyStreet Pro heads ($1300.00-$1450.00). The SE CNC heads flow slightly higher numbers due to large ports and valves than our Street Pro heads but suffer from other issues which tends to make the HP numbers about equal. So it is somewhat about price but we also have customers who want to be stealthy and therefore prefer not to have the SE script on the heads.

No reason to suspect published compression ratios, they are typ. within .2 of adverstized. Kits using our Superstock heads and the 251 cams typically get 100-105hp and 105-110 tq (STD, 5th gear, 250i dyno, 5speed trans). Well optimized (2-1 exhuast, 50mm t-body, large air cleaner, good tune) have gone 105-112hp and 110-115 peak torque. Of course the oposite is true. Restricted exhuast/air cleaners can reduce these numbers dramatically. For example, same setup with SE Performance Touring slip-on mufflers will typ. go 90-95hp/100-105tq.

Thanks, Mike

[jackio]

Thank you. Can I take your last comments on mufflers to mean that the slip-ons with stock headers will be too restrictive with the SE 103"? I was thinking about Rinehart slip-ons. I've heard that the stock headers are good for low-med tq, but are you saying that is still not the case if you move up to the 103" with the SEP heads? Thanks

[Mike]

It's all about the shape of and, where you want, your power band to be. Knowing that concentrating on low end power typically will result in a reduction of high end power (peak dyno numbers). The stock head pipe can become a resriction on aggressive 103's but works fine on typical (and CVO) 103 builds and what they are used for. We do a "Y" pipe modification that reduces some of the restriction and when used with a good slip-on muffler (Vance and Hines Classic Round, for instance) gives very good low end numbers with a good high end. The RhineHarts and SE slip-ons both exhibit a torque dip around 2500 rpm. The RhineHarts will make very good high end numbers where the SE's sign off at around 4500. As you add flow capacity through the heads, these effects can become greater but it is more a function of the wider cam timing we normally introduce along with those heads.
Thanks,Mike