john.r.davies Posted February 3, 2022 Report Share Posted February 3, 2022 This one for anybody with a TR7V8 that has four carbs in the Vee. I'm building, very slowly, a V8 powered car (not a TR) that has a 'boxer' inlet manifold with four HIF-type SU carbs on it. See below. I'm running control cables to them, and find that while they throttle all at once via a linkage, the choke control only appears to adjust the rear two. The front carbs have choke controls, but I can't see any linkage. Would choking just two of them be sufficient for cold starts, or should I be striving to adjust them all at once? Thanks! John Quote Link to post Share on other sites
jerrytr5 Posted February 3, 2022 Report Share Posted February 3, 2022 Not really my area John, but I would have thought 2 would be sufficient to get it going. Doesn't look like the sort of engine to be tootaling down the shops on a frosty morning. Jerry Quote Link to post Share on other sites
john.r.davies Posted February 4, 2022 Author Report Share Posted February 4, 2022 Thanks, jerry! But I posted this on the TR7/8 forum, in the hope that it would be in the area of some! Still hoping! Quote Link to post Share on other sites
BusheyTrader Posted February 4, 2022 Report Share Posted February 4, 2022 Have you tried the V8 forum? https://www.v8forum.co.uk/forum/index.php Quote Link to post Share on other sites
Wayne Scott Posted February 5, 2022 Report Share Posted February 5, 2022 With 4 x SUs , I would be surprised if you ever needed to use any choke at all to start from cold, unless maybe you're regularly starting on sub-zero frosty mornings! Quote Link to post Share on other sites
john.r.davies Posted February 5, 2022 Author Report Share Posted February 5, 2022 Thank you, BT and Wayne! I have asked elsewhere, and have been relieved to hear, suck it and see - you'll probably be OK. Not a problem to add a linkage, I'd just like to be able to tick that off the massive list of others in a total self build. Quote Link to post Share on other sites
BusheyTrader Posted February 5, 2022 Report Share Posted February 5, 2022 I don’t use the choke on myHolley equipped V8, nor do some pals with Edelbrock carbs. on mine, once I’ve primed the carb with a few strokes of the accelerator pedal it starts first time. Quote Link to post Share on other sites
john.r.davies Posted February 5, 2022 Author Report Share Posted February 5, 2022 But mine won't have Edelbrocks, BT! Quote Link to post Share on other sites
BusheyTrader Posted February 5, 2022 Report Share Posted February 5, 2022 2 hours ago, john.r.davies said: But mine won't have Edelbrocks, BT! Just adding to the comment about RV8s not being dependant on the choke to start from cold. Quote Link to post Share on other sites
john.r.davies Posted February 5, 2022 Author Report Share Posted February 5, 2022 Thanks, BT, the concensus seems to be not needed! Quote Link to post Share on other sites
jerrytr5 Posted February 5, 2022 Report Share Posted February 5, 2022 Wouldn't that be because Holley, Edelbrock & weber designs feature an accelerator pump so you can feed neat fuel in instead of a choke? SU's do not have this feature. Jerry Quote Link to post Share on other sites
BusheyTrader Posted February 5, 2022 Report Share Posted February 5, 2022 (edited) Yes, I use the accelerator pump to squirt fuel straight in to the inlet manifold before turning the key for an immediate cold start. I don’t have to apply the choke to keep the RV8 from dying at idle or low revs until it’s warmed up. With the 2.0L engine on twin SU’s back in the day, I found the choke necessary to fire up from cold and also prevent it from dying at idle until warmed up. Edited February 5, 2022 by BusheyTrader Quote Link to post Share on other sites
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