Bad weekend

[newguy]

Took the 3A out last Sat. Everything running beautifully. Decided to push her a little harder than normal.(still kept it below 4500 revs) All of a sudden, a noise I was not familiar with and didn't like. Make a long story short, broken pushrod, intake #3 cylinder. The good news, was already thinking about pulling the motor and doing a major rebuild. Going to 87MM, different cam, port and polish the head,new rear mail seal and more. Any ideas would be gratefully appreciated. Motor is out of car, now is the time to do it properly.

 

[DNK]

Seems to be going around. I would inoculate all LBC's I think

 

[MGTF1250Dave]

Aloha,

Don't forget to upgrade to 3/8" push rods.

 

[JKB1957]

I just rebuilt my 3's engine earlier this year. Did pretty much what you want to do, but also put in a header and APT bolts. If your cooling system is suspect now is also the time to upgrade, or re-core, your radiator and maybe add an oil cooler. Not cheap, especially if you go for an aluminum rad, but cheaper and easier then doing a second engine rebuild. Oh and beware of "new" oil pumps. I sheared the rotor off of a new pump less then a minute into the initial cam break in run. I reinstalled my 50 year old used oil pump and it's run perfect. A point of interest, you can actually remove and and reinstall a TR3 oil pump from underneath the car without removing the engine. Trust me, not a fun project.

 

[TR3driver]

I heard a rumor that Larry Young is looking for cam orders, to do another run of them. Haven't had a chance to try his new "street" cam for the TR2-4A, but the racers sure seem to love his "race" cam.

Sure wish I knew the specs for the "3/4 Race" cam I got from Bap-Geon some 35 years ago. Combined with just a cheap header from Warshawski's and TR4A exhaust valves, that engine would haul. I gave up street racing, though, after it broke a tooth out of the differential.

That was a few years after Dad's TR3 swallowed a valve ... I changed not only the oil pump, but liners, pistons, rod bearing, main bearings, etc. with the engine still in the car, parked in the snow!

 

[Perrymip]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]broken pushrod[/QUOTE]

Not to dampen your enthusiasm for a massive engine project, but isn't a pushrod a fairly easy fix?

 

[Brosky]

It depends what happened when the pushrod let go and if it jammed anything else up causing a "major" issue.

 

[newguy]

Thanks for all the feed back. For Perrymip: Brosky is 100% correct. JKB1957: Did you meen API studs? Also, is there a consensus on a good header for the street? Thanks again.

 

[vivdownunder]

Suggest you don't make the 3A head inlet ports any larger in diameter, as the gas tends to stall. Updated TR4A heads went to smaller diameter inlet ports for improved gas velocity, and that's the head racers like.

Viv.

 

[PeterK]

3rd time's the charm: "ARP" studs probably from aptfast.com.

 

[Don Elliott]

Randall - Where else in "Sunny So. Calif." (your words - not mine) do you get snow unless you live up near Herman on Bear Mountain ?

Or was that sometime in the previous millenium before global warming ?

 

[TR3driver]

Randall - Where else in "Sunny So. Calif." (your words - not mine) do you get snow unless you live up near Herman on Bear Mountain ?

There are mountains much closer to where I live than that; on a clear day in winter I can see snow from my backyard! But my parents live in Indiana (and at the time mentioned above, I did too). Not quite so sunny there, in the wintertime.

 

[TR3driver]

BTW, the "Competition Guides" (written by Kas Kastner) give pretty good instructions for improving the head. As I recall, the TR4 version had more engine information. Reprints are available from the usual suspects.

Kas has also published some newer Triumph books, with information more appropriate to serious racers today. But there is a huge amount of information, and I'm not sure it's any better for the street.

 

[curtislesa]

what's the outcome?

 

[newguy]

Motor is out, gives me a chance to get into the engine compartment and really clean things properly. Going with 89MM sleeves and pistons. Complete rotating assembly balanced. Lightened and balanced flywheel. All parts out being boiled clean and machined. CCing head to confirm how much we are going to shave off. Looking for a max of about 9.25 to 9.50 compression ratio. Any comments on headers for the street would be appreciated. Also any reccomendations on brand, material,(SS/mild steel) and so forth. Thanks again.