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Triumph TR6 - intake vacuum no gas

Being a novice to this awesome site I posted my original question in the wrong area. Triumph New ??

Anyway.. 74 TR6 New engine rebuild. .030 over, GP2 Cam, headers, trip carbs, roller rockers. Timing checked and rechecked at TDC.. 3 psi on fuel pump, plenty of gas.

At start up / crank over we can detect no vacuum at the intake side of the carbs.. the engine is getting no gas whatsoever.. crank and crank and crank.. pull plugs.. not a hint of gas.. Used a unisyn vacuum guage and nothing. Carbs are full of gas, pulled 1 off to check.. float heights right on.. carbs were rebuilt last year and ran great ! Pulled off all three fuel intake lines 1 at a time squirting hi pressure fuel into a rag and my forehead. So it's getting fuel.

Anybody have any ideas? How much vacuum should there be at start-up crank over ?? I can't find a spec anywhere on this.

Cheers
Garry
Garry Burgess

Are you getting spark?
DON KELLY

Sounds like valve timing/adjustment.
JT White

Good point, who installed the cam?
DON KELLY

Checking the valve timing would be at the top of my suspects list. The factory repair manual suggests this routine:
1. Set #11 valves to .120"
2. Turn crank until #1 cyl. is at TDC on the compresion stroke.
3. Valve clearances on #11 valves should be equal.
I think the above procedure should work on any symetrical cam. Might be a good idea to check that the TDC mark on the damper is accurate first. Anybody have a different method?
Berry
BTP Price

Thanks guys... Lots of spark Don... my thinking exactly JT.. The timing gear and sprocket came from TRF with no marks whatsoever.. My engine rebuilder
(40 yrs. in business with a great reputation) was big time surprised about the no marks so they had to degree wheel time the engine and I don't think they had done a complete d/w time job for a while. It's a GP2 cam from Richard G.. Weird part as I understand is that I shouldn't be getting 125 compression across the board... should I ?? I'll get into the manual re BTP's idea.

Thanks Garry
Garry Burgess

Garry-In re-reading my post, I must have had a senior moment. Step #1 should read: Set the #11 valves to .120". Step #3 should read: Valve clearances on the #11 should be equal. Sorry.
Berry
BTP Price

Already there Berry and printed. Off to the shop.
Thnx.
Garry Burgess

It still is not right. Step #1 should read: Set #11 and #12 valves to .120". Step#3 should read: Valve clearances on #11 and #12 valves should be equal when crank is at TDC on the compression stroke of #1 cyl. You might check with Richard Good for his recommendation.
Berry
BTP Price

Gad Berry, I thought it was just me.
Thanks for the clarification
DON KELLY

Don-I think some bad habits from youth are starting to take their toll.
Berry
BTP Price

OK.. I'm dizzy now, thanks. I'll call Richard in the morning.
CFB
Garry Burgess

Well I'm back and the 74 TR6 is purrrring well.
Richard Good was awesome and walked me through an awesome quick check of the GP2 cam and the overall timing of the engine in 10 minutes... That took my mind off the degree wheel timing issue and put me on to the trip carbs to see what the hell was going on.
Found it in 5 minutes.. Opened up my amazing SZ 175 Carb pages that I got off the Buckeye Ohio website ( you really should take a look at the Stromberg Z link... awesome to say the least.) In all my hurry to get this car out of the shop with the help of my 19 year old son ... he put the main carb gasket ( that thick son of a b...h) on backwards and to stare at it I had to look twice to realize the notches did not line up to the carb notches and of course the small vent hole was covered by the gaskets and then 2 f...g hours later ( 3 carbs are much harder than 2) It started right away. 20 minutes @ 2,000 RPM to break the cam in and we're good.

Thanks to everyone for their input.
Garry

Garry Burgess

This thread was discussed between 23/05/2010 and 28/05/2010

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