1960 Trimph Pre Unit drag bike project.

[1947knuck]

I bought a 59 frame from Dan@Angry Monkey years ago, a hardtail from TFMW, a 71 front end and a 60 model 650 engine and transmission off the clasifieds at JJ. The pieces have been sitting in the shop gathering dust for several years while I worked on other projects until 2 months ago when I decided to start putting the bike together. I bought an Aisin AMR300 off ebay that looked new and modified an S&S Super B with a Holley 650 carburetor bowl. Buchanan Spokes laced up the 18 inch rim and a friend of mine installed the M&H slick. I have the parts mocked up and still aways to go so I thought I would post some pictures of where the bike is know.

[TriNortchopz]

Cool setup.How will you be mounting that carb? Any idea of the rpm that blower will spin at with that sprocket drive and ratio? Just wondering how you determined the drive ratio (looks like 1:1).

[nuklhd]

I dig what you have going so far. keep us updated.

[1947knuck]

Cool setup.How will you be mounting that carb? Any idea of the rpm that blower will spin at with that sprocket drive and ratio? Just wondering how you determined the drive ratio (looks like 1:1).

The carburetor is in the position it will be when finished. Even though the carburetor is at a 90 degree difference than the blower the outlet end of the carburetor and the inlet side of the blower are at a staight line up. The intake manifold will travel straight up 3 inches with 90 degree curves at the carburetor and blower on a straight intake manifold. Since the carburetor doesn't have to depend on a drop in atmospheric pressure to create a vacum instead using the blower drawing the air fuel mixture up it should work just fine with the correct tunning. The sprockets are 20 teeth at the primary and 18 on the blower drive, a 1.11 slight overdrive. I'm not sure this will be the final overdrive ratio at this point it will depend on the cam & final engine compression of the engine. I'm looking for maximun horsepower @ 6500 engine RPM. The blower has a recommended 10,000 RPM maximum, so the blower could be overdriven 1.5. at this engine RPM.

[TriNortchopz]

..."The sprockets are 20 teeth at the primary and 18 on the blower drive, a 1.11 slight overdrive...I'm looking for maximun horsepower @ 6500 engine RPM. The blower has a recommended 10,000 RPM maximum, so the blower could be overdriven 1.5. at this engine RPM."

Sounds good. Just curious' 20/18 are the sprockets between the primary chain and blower shaft right?
The motor is a 1960? Read that the primary engine sprocket in 1960 was changed to a 22T from a 24T sprocket the previous year...I think you will need to take that into consideration when determining your blower rpm vs. engine rpm. Is the clutch sprocket 43T? Do you think the 22T would be better than a 24T for your blown drag bike? Stock, the max. engine output was 46 hp was at 6,500 rpm. This was for the dual-carb Bonneville...not sure how that compares with your single carb model.

Got that info here:

http://www.classic-british-motorcycles.com/1960-triumph-bonneville.html

Looked at the TR6 for 1960; it had 21T/43T primary sprockets:

http://www.classic-british-motorcycles.com/1960-triumph-tr6.html

[1947knuck]

Sounds good. Just curious' 20/18 are the sprockets between the primary chain and blower shaft right?
The motor is a 1960? Read that the primary engine sprocket in 1960 was changed to a 22T from a 24T sprocket the previous year...I think you will need to take that into consideration when determining your blower rpm vs. engine rpm. Is the clutch sprocket 43T? Do you think the 22T would be better than a 24T for your blown drag bike? Stock, the max. engine output was 46 hp was at 6,500 rpm. This was for the dual-carb Bonneville...not sure how that compares with your single carb model.

Got that info here:

http://www.classic-british-motorcycles.com/1960-triumph-bonneville.html

Looked at the TR6 for 1960; it had 21T/43T primary sprockets:
http://www.classic-british-motorcycl...iumph-tr6.html

I changed the original 21T/43T single chain sprockets that came on pre units to the later double row unit chain, sprocket and clutch hub that are 29T engine and 58T clutch hub. The ratio on the pre unit set up is 2:00 and on the later unit set up I have now is 2:05. I wont make a final decision on the 20/18 sprockets that currently drive the blower until the engine is fired and I get the tuning and the blower drive ratio finalized along with monitoring the RPM of the blower compared to the RPM of the engine during the tunning.

[Dougtheinternetannoyance123]

Interesting fab work and build. Id like to see more details on the super charger/Blower?? Or can you point a link to info on them?

What kind of racing are you going for?? Is there specific classes or a "Run whatcha brung" type racing you are going for? I know some guys running the extreme drag bikes, but dont know much about the other classes and if this is a local track thing or going for a series? (We spent years researching Landspeed racing and built our bike to compete in specific classes)

2 points if you (hopefully dont mind indulging me/us) On a draw thru setup like that, My understanding is a backfire or hickup can be rather distressing, Sometimes fires? Any pop off valve or sacrificial bolts or something? Ive been at the track when Automotive versions went Kablooie... Maybe this is not an issue on yours, But its possible, whats your thoughts on this?

The carb, Being a draw thru, finite tuning is probably not needed or is it?? I know on research on this vs blow thru some mods have to be done. Maybe not, but is that an issue here? Did you pick that carb for reasons of familialirty/had on the shelf/recomended/ or replicating another build?

Starting, Im just guessing here, but it might be hard to start.. Rollers? I knew guys back in the day would have a squirt bottle and have to shoot a spritz of fuel into the intakes on cars otherwise they dont start.

Based on pictures, Here is my totally unsolicited observations :

A) Looks like a preunit head, certainly PU Rocker boxs, Is that a "had it on the shelf" or a class restriction for racing? Early ones had issues and tech materials put out by MAP cycle and a few others shows a big benefit to the later the cyl head the better the performance so not unusual to see a 9 or 10 bolt late head on a early bottom end.
(I **LOVE** The late style big oval rockerboxs as they make it so much easier to adjust the valves and do timing work)

B) Chains! So many Chains! Certainly very steam punk, but thats a lot of flinging-whipping-pulsating metal with a lot of velocity aimed at your twig & berries. I personally **LOVE** Belt primaries, final drives and even belt driven ignition, charging, etc,,
(BSA Preunits a popular mod is to convert the generator/dynamo to belt also) Im sure you are well aware but a belt if it fails does not sever body parts, shatter cases and spit shrapnel everywhere. Not to mention losing a lot of weight and recip. weight at that. I used to keep a belt kit in stock and many customers opted for one with a simple "Hold one in each hand" comparison.
Gates and a number of other industrial suppliers have online custom design software so it would be easy and affordable to make a kit for your supercharger/blower as well as you can do some fine tuning with drive ratio's Is that an option for you or considered that?

Im sure you have your bases covered so this is just dumb questions from the cheap seats, But I will say, I hope you have a good balance guy. Nothing beats a dynamic balancing job. If you need one my guy is awesome here in Oregon.

Heres a few photos of the worlds fastest vintage Norton 500 twin. (We used 750 cases) Not-runs are backwards so Sir Eddy did some presto-chango custom machine work and its now DeSaxe and then modified into a 270 degree crank, The first attempt was beautiful but wouldnt be able to go to our RPMs, so a very expensive one piece crank was commisioned which took over a year to get done. Custom cams, External oiling & segmented pump, custom H beam rods and some very top secret at the time modified cyl head, If you havent read up on it, research SINGH GROOVES.. That shit WORKS! The cyl was a custom machine job out of 6061 billet with little grooves cut to duct air to the rear as expansion and heat distro is not even. Thats basically 10 years worth of work.

[1947knuck]

[QUOTE=Dougtheinternetannoyance123;805959]Interesting fab work and build. Id like to see more details on the super charger/Blower?? Or can you point a link to info on them?

WWW.Elsberg-Tuning-DK is a site that has information on the AMR300 that I'm using along with an interesting read on different small blowers. Most of the information I got was from different Brit Bike sites about instalation,etc. I repositioned the blower drive closer to the engine sprocket and have started the chain guard designs. It going to be close in design to the one pictured here.My bike is not being built for a specific class, more of just a run what you brung type of bike. I am going to install a pop off valve similar to the one pictured except mine is going to attach at the underside of the intake manifold. As far as the carburetor I picked it because I am familiar with modifying the Super B, it should be an easy tune for this bike, and if it turns out to need an acelerator pump, that can be easily installed. As far as starting it I'm going to use a portable roller, I'm sure you've seen them with a small gas engine and a rubber wheel, it's the same style that is used on early Board Track racers like the one pictured here. This is an early bike I have all but finished, and it's a screamer. Your correct it is an early Pre Unit head, the engine runs as is stock but once I'm finished with the fabrication I'm going to consider a later head during the engine build it seems to be the way to go.
When you stand back there are alot of chains doing work on this bike. The way the blower is mounted requires it to run the opposite direction of the engine rotation, I could turn the blower over but that would put the blower sprocket closer to the rider and require a longer chain drive. In order to run the blower the way it's mounted I had to change the clutch drive to the later unit style with a double roller chain. That way I could use two spockets, one on the inside of the primary chain and the other to drive the blower. I think the chains lend to a more vintage look and fits what I'm wanting to accomplish with the build.

[1947knuck]

I want this bike to have a vintage look to fit a dragster I have. I bought a 1960 Dragmaster Dragster original rolling chassis and restored it to just how it would have been in 1960, all the correct vintage pieces along with a 1960 283 engine bored .125 over stroked 1/2 inch to make 354 cubic inches with an original GMC 6-71 blower. Dode Martin the builder of the dragster in 1960 built the engine for me when he was 91 to complete the restoration. Not to turn this into a dragster thread but here is a before and after picture. I accidently posted a before pictue in my last post.
I don't have anyone in mind to do the balancing on the engine, something I am definitely going to do. I have built Harley engines, but even then I sent the crank assy off to balance and had someone in the know do the head work etc., basically I would assemble the engine once the precision work was done. I don't have any experiance with Triumph engines so I will need to find someone that can do the balancing, head work, etc., than I will assemble it. If you have someone in mind that can do that work I would be happy to get their information from you.
The pictures of the Norton engine and the information you supplied is so cool. Later tonight I will research Singh Grooves while I'm relaxing. I have allways been into Harleys but it is hard to beat a good looking Triumph, Norton or BSA engine when their cleaned up and detailed. I appreciate you taking the time to send me the pictures, suggestions and and comment of my build. Thanks Charles.

[Dougtheinternetannoyance123]

Thanks for the compliment Charles,, I really am enjoying what you are doing, And please understand I am not telling you to do anything, But when someone offers up something like this, as long as the feedback is respectful most people enjoy it, I do, Heck I do stupid stuff all the time and eternally grateful for people taking the time to offer advice. There is much to be learned from others. I usually try to learn from old guys who have done this stuff as I dont have to re-invent the wheel, But sometimes its also useful to learn what NOT to do..!
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I love your dragster car project, going off on a tangent here, But I have a soft spot for 283's. Had several Novas (1963 SS & 64 SS) and in a small light car with a Muncie they are a great motor. I went down the path with Big Blocks and had several and they are fun, But a boat anchor, Give me a well built SBC anyday. Mrs Doug has her own project, A 1969 Chevelle and not a high dollar build but what we each grew up with & around in the 70s & 80s,, You are lucky to find an old salt who knows all the old speed secrets, PICK THAT MANS BRAIN! Its fast disappearing tribal knowledge! Im a big fan of the muscle car-Trans Am wars from the 60s and early 70s. My dad took me to many of the road races and some seriously cool cars back then. Many were running stroker and modified 283s in different configs like yours. Also went to the drags a lot in the 1970s,, I once saw TV Tommy Ivo run over his crew chief in his funny car at PIR in 72-73?

Id be happy to spit ball Triumph tech with you, I used to run a shop, still have a lot of stuff left over from those days and any racer I could I interrogated them and picked up a lot of tech I have adapted and built on.

So could write some small books here on the topic (and I get complaints about my long answers from the ADD-ADHD/Crackberry crowd as it makes their thumbs sore to scroll..

But Heres 2 things off the top of my head.. Im not an expert at turbos and supercharging but know some who have done it. One nutjob good friend of mine has a Norton with a Drouin supercharger, Nortons have enough issues without supercharging, But he has about 15 years invested in his. But some folks I know in the UK doing sprinting (UK Version of drag racing) MOST with superchargers or turbos have to THRU BOLT the top ends. Some build a vise like structure to mash down the head-cyl-cases, some run extended waisted high tensile bolts top to bottom.

A Preunit 8 bolt head blows gaskets to begin with, Plus will crack out to the bolts from the exhaust seats. There is fixes for it.
Machine and sleeve the bolt holes and leave the cracks, But the later heads added meat to the casting so the 9 bolt is better than a 8 bolt and a 10 bolt is the best. (From a casting point of view, flow and HP are a separate issue)

A nutter Canadian I know, Ken B, I sponsored him one year in AHRMA got friendly with Dick Mann and got the rules changed to allow in TRIBSAS. BSA PU frames with All alloy PU Triumph 500 motors (Some use a norton box, some BSA some Triumph)
TRIBSAs dominate when legal to run for road racing and MX. So Ken went hog wild the first year and was DNF every race.
It went like stink but something always broke. He was using a all alloy cyl and head and 11:1, Hot cams and other hot parts.
Went like stink for short bursts. A BIG problem was it pulled the cyl studs out of the cases! Dick Mann and others told him he was over thinking it.. Detuned it and started finishing races and winning. The lesson I learned was, Either A) Build to win with parts that can handle the power, Or B) Learn to adapt with what you have to work with.

So I like what you are doing, But I think you might stuggle with parts of it, One point to pay attention to... ANY slight shift or torquing, or flexing (And believe me a preunit flexs a LOT) your alignments are going to be problematic. That chain setup with even a little misalignment or shift will be a problem. Id love to see it work, But I think thats why the other examples are using belts as well.

more soon, Very cool!

[1947knuck]

I got the intake from carb to blower mocked up. The intake is in two pieces so I have a hose clamp holding the two pieces together and a tie strap holding it in place while I do the final fitting before Heil-Arc welding everything together. I also got the oil filter installed below the oil tank.